Cognitive decrements in 1991 Gulf War veterans: associations with Gulf War illness and neurotoxicant exposures in the Boston Biorepository, Recruitment, and Integrative Network (BBRAIN) cohorts.

BACKGROUND: During deployment, veterans of the 1991 Gulf War (GW) were exposed to multiple war-related toxicants. Roughly a third of these veterans continue to exhibit neurotoxicant induced symptoms of Gulf War Illness (GWI), a multi-faceted condition that includes fatigue, pain and cognitive decrements. When studied empirically, both deployed veterans with exposures and those who meet the criteria for GWI are more likely to show deficits in the area of neuropsychological functioning. Although studies have shown cognitive impairments in small sample sizes, it is necessary to revisit these findings with larger samples and newer cohorts to see if other areas of deficit emerge with more power to detect such differences. A group of researchers and clinicians with expertise in the area of GWI have identified common data elements (CDE) for use in research samples to compare data sets. At the same time, a subgroup of researchers created a new repository to share these cognitive data and biospecimens within the GWI research community. METHODS: The present study aimed to compare cognitive measures of attention, executive functioning, and verbal memory in a large sample of GWI cases and healthy GW veteran controls using neuropsychological tests recommended in the CDEs. We additionally subdivided samples based on the specific neurotoxicant exposures related to cognitive deficits and compared exposed versus non-exposed veterans regardless of case criteria status. The total sample utilized cognitive testing outcomes from the newly collated Boston, Biorepository, Recruitment, and Integrative Network (BBRAIN) for GWI. RESULTS: Participants included 411 GW veterans, 312 GWI (cases) and 99 healthy veterans (controls). Veterans with GWI showed significantly poorer attention, executive functioning, learning, and short-and-long term verbal memory than those without GWI. Further, GW veterans with exposures to acetylcholinesterase inhibiting pesticides and nerve gas agents, had worse performance on executive function tasks. Veterans with exposure to oil well fires had worse performance on verbal memory and those with pyridostigmine bromide anti-nerve gas pill exposures had better verbal memory and worse performance on an attention task compared to unexposed veterans. CONCLUSIONS: This study replicates prior results regarding the utility of the currently recommended CDEs in determining impairments in cognitive functioning in veterans with GWI in a new widely-available repository cohort and provides further evidence of cognitive decrements in GW veterans related to war-related neurotoxicant exposures.

Prior automatic posture and activity identification improves physical activity energy expenditure prediction from hip-worn triaxial accelerometry.

Accelerometry is increasingly used to quantify physical activity (PA) and related energy expenditure (EE). Linear regression models designed to derive PAEE from accelerometry-counts have shown their limits, mostly due to the lack of consideration of the nature of activities performed. Here we tested whether a model coupling an automatic activity/posture recognition (AAR) algorithm with an activity-specific count-based model, developed in 61 subjects in laboratory conditions, improved PAEE and total EE (TEE) predictions from a hip-worn triaxial-accelerometer (ActigraphGT3X+) in free-living conditions. Data from two independent subject groups of varying body mass index and age were considered: 20 subjects engaged in a 3-h urban-circuit, with activity-by-activity reference PAEE from combined heart-rate and accelerometry monitoring (Actiheart); and 56 subjects involved in a 14-day trial, with PAEE and TEE measured using the doubly-labeled water method. PAEE was estimated from accelerometry using the activity-specific model coupled to the AAR algorithm (AAR model), a simple linear model (SLM), and equations provided by the companion-software of used activity-devices (Freedson and Actiheart models). AAR-model predictions were in closer agreement with selected references than those from other count-based models, both for PAEE during the urban-circuit (RMSE = 6.19 vs 7.90 for SLM and 9.62 kJ/min for Freedson) and for EE over the 14-day trial, reaching Actiheart performances in the latter (PAEE: RMSE = 0.93 vs. 1.53 for SLM, 1.43 for Freedson, 0.91 MJ/day for Actiheart; TEE: RMSE = 1.05 vs. 1.57 for SLM, 1.70 for Freedson, 0.95 MJ/day for Actiheart). Overall, the AAR model resulted in a 43% increase of daily PAEE variance explained by accelerometry predictions. NEW & NOTEWORTHY Although triaxial accelerometry is widely used in free-living conditions to assess the impact of physical activity energy expenditure (PAEE) on health, its precision and accuracy are often debated. Here we developed and validated an activity-specific model which, coupled with an automatic activity-recognition algorithm, improved the variance explained by the predictions from accelerometry counts by 43% of daily PAEE compared with models relying on a simple relationship between accelerometry counts and EE.

Factors associated with outcome in 94 hospitalised foals diagnosed with neonatal encephalopathy.

REASONS FOR PERFORMING STUDY: Neonatal encephalopathy is the most common neurological abnormality identified in neonatal foals, but its clinical course has been rarely characterised. OBJECTIVES: To describe factors associated with nonsurvival in a population of foals diagnosed with neonatal encephalopathy. STUDY DESIGN: Retrospective cross-sectional clinical study. METHODS: Cases were selected from equine neonatal (≤14 days of age) admissions between 1996 and 2007. Multivariable logistic regression was used to identify clinical parameters, laboratory variables and therapeutic interventions associated with nonsurvival. RESULTS: A total of 94 foals were included in the study. Median age at admission was 12 h (range 0-96 h). The most frequently identified clinical signs included abnormal udder seeking (59%), abnormal suckle (55%), inability to stand (42%), abnormal gastrointestinal motility (37%), abnormal consciousness (34%) and seizure activity (22%). Overall, 75 (79.8%) foals survived to be discharged from the hospital and 19 foals died or were subjected to euthanasia. Variables significantly associated with nonsurvival in the multivariable model were serum total calcium concentration, serum activity of alkaline phosphatase, recumbency, number of concurrent diseases, and use of vasopressors/inotropes. The model correctly classified 92.0% of cases. CONCLUSIONS: Overall survival was good and similar to previous reports. Vasopressors/inotropes were the only therapeutic intervention associated with nonsurvival, suggesting that persistent hypotension is associated with nonsurvival in the current population. Foals with concurrent disease, high total calcium and low alkaline phosphatase at admission, and that were recumbent or required treatment with vasopressors/inotropes during hospitalisation, were significantly less likely to survive.

Inequality-related economic burden of communicable diseases in Canada.

BACKGROUND: Communicable diseases cause a significant burden on society in terms of health care expenditures and their health impact on individuals. Cost-of-illness studies estimate the total economic burden of illness and injury. OBJECTIVE: To identify the economic burden of illness for communicable diseases in Canada, and to derive the costs associated with inequalities based on income and hospital expenditures. METHODS: Data were derived from the Economic Burden of Illness in Canada (EBIC) database, for the year 2008. Data for communicable diseases were extracted and compared to the overall results. Data on income level was available for hospital expenditures, and was analyzed by income quintile. RESULTS: The total costs attributable to communicable diseases in Canada were $8.3 billion, which represented 9% of the total costs that could be attributed to a specific disease or diagnostic category. Indirect costs accounted for 44% of total communicable disease costs and represented a more significant proportion of the economic burden related to communicable diseases compared to non-communicable diseases. When hospital costs by income quintile were analyzed, a clear inverse relationship was found between income and hospital expenditures. The costs associated with this inequality in 2008 were $308 million. The current estimates are likely to be an underestimate due to the conservative assumptions made in the analysis. CONCLUSION: The cost of communicable disease in Canada is sizable and there is a clear correlation between lower income and higher hospital costs. Further research is needed to better account for co-morbid conditions and to better estimate the value of lost productivity related to disability arising from communicable diseases.

Tibiofemoral contact biomechanics following meniscocapsular separation and repair.

Meniscocapsular separations are often seen in knees with other intra-articular pathology. The consequences of these tears with regard to knee contact mechanics are currently unknown, and the biomechanical advantages of repair have not been measured. We hypothesize that tears to the meniscocapsular junction will cause an increase in tibiofemoral contact pressure and a decrease in contact area, with a return to more normal conditions after repair. 10 fresh-frozen cadaver knees each underwent 10 cycles of axial compressive loading in full extension under three different testing conditions: intact, meniscocapsular separation, and repair. A pressure sensor matrix was inserted into the medial joint space and used to measure magnitude and location of contact pressure and area. Mean contact pressure increased from 0.80±0.17 MPa in the intact knee to 0.88±0.19 MPa with separation, with a decrease to 0.78±0.14 MPa following repair. Peak pressures followed a similar trend with 2.59±0.41, 3.03±0.48, and 2.84±0.40 MPa for the same three groups, respectively. While none of the changes seen was statistically significant, even these small changes would potentially create degenerative changes at the articular surface over prolonged (i. e., months or years) standing, walking, and activity in the unrepaired state.

A socio-ecological approach promoting physical activity and limiting sedentary behavior in adolescence showed weight benefits maintained 2.5 years after intervention cessation.

BACKGROUND: Obesity in youth remains a major public health issue. Yet no effective long-term preventive strategy exists. We previously showed that a school-based socio-ecological approach targeting behavior and social/environmental influences on physical activity (PA) prevented 4-year excessive weight gain in 12-year olds. In this study, we investigated if this efficacy persists 30 months after intervention cessation. METHODS AND FINDINGS: The program targeted students, family, school and the living environment to promote/support PA and prevent sedentary behavior (SB). A total of 732 students from eight randomized middle schools completed the 4-year trial. At the 30-month post-trial follow-up, body mass index (BMI), fat mass index (FMI), leisure PA (LPA), home/school/workplace active commuting, TV/video time (TVT), and attitudes toward PA were measured in 531 adolescents. The beneficial effects of the intervention on the excess BMI increase (+0.01 vs +0.34 kg m(-2) in the intervention and control groups, respectively) and on the overweight incidence in initially non-overweight students (4.3% vs 8.6%; odds ratio=0.48 (95% confidence interval: 0.23-1.01)) were maintained at the post-trial follow-up. LPA was not maintained at the level achieved during the trial. However, we still observed a prevention of the age-related decrease of the adolescents' percentage reporting regular LPA (-14.4% vs -26.5%) and a higher intention to exercise in the intervention group. The intervention promoted lower TVT (-14.0 vs +13.6 min per day) and higher active commuting changes (+11.7% vs -4.8%). Trends in higher BMI reduction in students with high initial TVT and in the least wealthy group were noted. TVT changes throughout the follow-up predicted excess BMI and FMI changes. CONCLUSIONS: Long-term multilevel approach targeting PA and SB prevents excessive weight gain up to 30 months after intervention cessation. The efficacy may be higher in the most sedentary and least wealthy adolescents. Healthy PA-related behavior inducing long-lasting weight effects can be promoted in youth providing that an ecological approach is introduced in the prevention strategy.

Validity of combining heart rate and uniaxial acceleration to measure free-living physical activity energy expenditure in young men.

Combining accelerometry (ACC) with heart rate (HR) monitoring is thought to improve activity energy expenditure (AEE) estimations compared with ACC alone to evaluate the validity of ACC and HR used alone or combined. The purpose of this study was to estimate AEE in free-living conditions compared with doubly labeled water (DLW). Ten-day free-living AEE was measured by a DLW protocol in 35 18- to 55-yr-old men (11 lean active; 12 lean sedentary; 12 overweight sedentary) wearing an Actiheart (combining ACC and HR) and a RT3 accelerometer. AEE was estimated using group or individual calibration of the HR/AEE relationship, based on an exercise-tolerance test. In a subset (n = 21), AEE changes (ΔAEE) were measured after 1 mo of detraining (active subjects) or an 8-wk training (sedentary subjects). Actiheart-combined ACC/HR estimates were more accurate than estimates from HR or ACC alone. Accuracy of the Actiheart group-calibrated ACC/HR estimates was modest [intraclass correlation coefficient (ICC) = 0.62], with no bias but high root mean square error (RMSE) and limits of agreement (LOA). The mean bias of the estimates was reduced by one-third, like RMSE and LOA, by individual calibration (ICC = 0.81). Contrasting with group-calibrated estimates, the Actiheart individual-calibrated ACC/HR estimates explained 40% of the variance of the DLW-ΔAEE (ICC = 0.63). This study supports a good level of agreement between the Actiheart ACC/HR estimates and DLW-measured AEE in lean and overweight men with varying fitness levels. Individual calibration of the HR/AEE relationship is necessary for AEE estimations at an individual level rather than at group scale and for ΔAEE evaluation.

Pro-neural miR-128 is a glioma tumor suppressor that targets mitogenic kinases.

MicroRNAs (miRNAs) carry out post-transcriptional control of a multitude of cellular processes. Aberrant expression of miRNA can lead to diseases, including cancer. Gliomas are aggressive brain tumors that are thought to arise from transformed glioma-initiating neural stem cells (giNSCs). With the use of giNSCs and human glioblastoma cells, we investigated the function of miRNAs in gliomas. We identified pro-neuronal miR-128 as a candidate glioma tumor suppressor miRNA. Decreased expression of miR-128 correlates with aggressive human glioma subtypes. With a combination of molecular, cellular and in vivo approaches, we characterize miR-128's tumor suppressive role. miR-128 represses giNSC growth by enhancing neuronal differentiation. miR-128 represses growth and mediates differentiation by targeting oncogenic receptor tyrosine kinases (RTKs) epithelial growth factor receptor and platelet-derived growth factor receptor-α. Using an autochthonous glioma mouse model, we demonstrated that miR-128 repressed gliomagenesis. We identified miR-128 as a glioma tumor suppressor that targets RTK signaling to repress giNSC self-renewal and enhance differentiation.

SU-E-T-155: Dose Response Curve of EBT2 and EBT3 Radiochromic Films to a Synchrotron-Produced Monochromatic X-Ray Beam.

PURPOSE: This work investigates the dose-response curves of Gafchromic EBT2 and EBT3 radiochromic films using synchrotron-produced monochromatic x-ray beams. These dosimeters are being utilized for dose verification in photoactivated Auger electron therapy at the LSU Center for Advanced Microstructures and Devices (CAMD) synchrotron facility. METHODS: Monochromatic beams of 25, 30 and 35 keV were generated on the tomography beamline at CAMD. Ion chamber depth-dose measurements were used to calculate the dose delivered to films irradiated simultaneously at depths from 0.7 - 8.5 cm in a 10×10×10-cms polymethylmethacrylate phantom. AAPM TG-61 protocol was applied to convert measured ionization into dose. Calibrations of films at 4 MV were obtained for comparison using a Clinac 21 EX radiotherapy accelerator at Mary Bird Perkins Cancer Center. Films were digitized using an Epson 1680 Professional flatbed scanner and analyzed using the optical density (OD) derived from the red channel. RESULTS: For EBT2 film the average sensitivity (OD/dose) at 50, 100, and 200 cGy relative to that for 4-MV x- rays was 1.07, 1.20, and 1.23 for 25, 30, and 35 keV, respectively. For EBT3 film the average sensitivity was within 3 % of unity for all three monochromatic beams. CONCLUSIONS: EBT2 film sensitivity shows strong energy dependence over an energy range of 25 keV - 4 MV. EBT3 film shows weak energy dependence, indicating that it would be the better dosimeter for Auger electron therapy. This research was supported by contract W81XWH-10-1-0005 awarded by The U.S. Army Research Acquisition Activity, 820 Chandler Street, Fort Detrick, MD 21702-5014. This report does not necessarily reflect the position or policy of the Government, and no official endorsement should be inferred.

Use of biocides and insect repellents and risk of hypospadias.

BACKGROUND: The relationship between the use of biocides and insect repellents and the risk of hypospadias was examined in a large case-control study in the South East of England. METHODS: A case-control study was carried out among 471 cases of hypospadias referred to surgeons, and 490 randomly selected population-based controls, born between 1 January 1997 and 30 September 1998. Telephone interviews were conducted between September 2000 and March 2003. The questionnaire included information on demographic, lifestyle and environmental factors, including the use of biocides and insect repellents, during pregnancy. A total biocide score was created from summing positive responses to an eight-item biocide exposure questionnaire. RESULTS: The use of insect repellent (adjusted OR 1.81, 95% CI 1.06 to 3.11) during the first trimester of pregnancy was associated with risk of hypospadias, but none of the biocides, or indicators for them, except for the total biocide score for the highest two exposure categories (score 3: adjusted OR 1.73, 95% CI 1.02 to 2.94; and scores 4 and 5 combined: adjusted OR 2.98, 95% CI 1.01 to 8.78) showed statistically significant associations. CONCLUSION: The authors found an association between the use of insect repellent and total biocide score and risk of hypospadias. In particular, the use of insect repellent warrants further investigation, specifically in relation to type, content and frequency of use since this information was missing in the current study.

Changes in plasma arginine vasopressin concentrations in cyclists participating in a 109-km cycle race.

OBJECTIVE: To evaluate the osmotic and non-osmotic regulation of arginine vasopressin (AVP) during endurance cycling. DESIGN: Observational study. Setting 109 km cycle race. PARTICIPANTS: 33 Cyclists. INTERVENTIONS: None. MAIN OUTCOME MEASUREMENTS: Plasma sodium concentration ([Na(+)]), plasma volume (PV) and plasma arginine vasopressin (AVP) concentration ([AVP](p)). RESULTS: A fourfold increase in [AVP](p) occurred despite a 2-mmol l(-1) decrease in plasma [Na(+)] combined with only modest (5%) PV contraction. A significant inverse correlation was noted between [AVP](p) Delta and urine osmolality Delta (r = -0.41, p<0.05), whereas non-significant inverse correlations were noted between [AVP](p) and both plasma [Na(+)] Delta and % PV Delta. Four cyclists finished the race with asymptomatic hyponatraemia. The only significant difference between the entire cohort with this subset of athletes was postrace plasma [Na(+)] (137.7 vs 133.5 mmol l(-1), p<0.001) and plasma [Na(+)] Delta (-1.9 vs -5.1 mmol l(-1), p<0.05). The mean prerace [AVP](p) of these four cyclists was just below the minimum detectable limit (0.3 pg ml(-1)) and increased marginally (0.4 pg ml(-1)) despite the decline in plasma [Na(+)]. CONCLUSIONS: The osmotic regulation of [AVP](p) during competitive cycling was overshadowed by non-osmotic AVP secretion. The modest decrease in PV was not the primary non-osmotic stimulus to AVP. Partial suppression of AVP occurred in four (12%) cyclists who developed hyponatraemia during 5 h of riding. Therefore, these results confirm that non-osmotic AVP secretion and exercise-associated hyponatraemia does, in fact, occur in cyclists participating in a 109 km cycle race. However, the stimuli to AVP is likely different between cycling and running.

Rates of fluid ingestion alter pacing but not thermoregulatory responses during prolonged exercise in hot and humid conditions with appropriate convective cooling.

The aim of the study was to examine the effects of fluid replacement on thermoregulation and cycling performance in hot, humid conditions. Six male cyclists (PPO = 426 +/- 39 W) performed six 80 km time trials. Subjects replaced 0% (0); 33% (33); 66% (66); or 100% (100) of the weight lost during an "ad libitum" trial (Ad Lib). In another condition (WET), subjects rinsed their mouths at 10 km intervals. There was no trial effect on any thermoregulatory variables or on performance. When WET, 0, 33 ("LO") were compared to Ad Lib; 66, 100 ("HI"), power output was higher in HI (209 +/- 22 vs. 193 +/- 22 W, p < 0.05). Restricting fluid below ad libitum rates impaired performance (LO group). Rates greater than ad libitum did not result in further improvements. Ad libitum fluid ingestion is optimal as it prevents athletes from ingesting too little or too much fluid.

Three independent biological mechanisms cause exercise-associated hyponatremia: evidence from 2,135 weighed competitive athletic performances.

To evaluate the role of fluid and Na+ balance in the development of exercise-associated hyponatremia (EAH), changes in serum Na+ concentrations ([Na+]) and in body weight were analyzed in 2,135 athletes in endurance events. Eighty-nine percent of athletes completed these events either euhydrated (39%) or with weight loss (50%) and with normal (80%) or elevated (13%) serum [Na+]. Of 231 (11%) athletes who gained weight during exercise, 70% were normonatremic or hypernatremic, 19% had a serum [Na+] between 129-135 mmol/liter, and 11% a serum [Na+] of <129 mmol/liter. Serum [Na+] after racing was a linear function with a negative slope of the body weight change during exercise. The final serum [Na+] in a subset of 18 subjects was predicted from the amount of Na+ that remained osmotically inactive at the completion of the trial. Weight gain consequent to excessive fluid consumption was the principal cause of a reduced serum [Na+] after exercise, yet most (70%) subjects who gained weight maintained or increased serum [Na+], requiring the addition of significant amounts of Na+ (>500 mmol) into an expanded volume of total body water. This Na+ likely originated from osmotically inactive, exchangeable stores. Thus, EAH occurs in athletes who (i) drink to excess during exercise, (ii) retain excess fluid because of inadequate suppression of antidiuretic hormone secretion, and (iii) osmotically inactivate circulating Na+ or fail to mobilize osmotically inactive sodium from internal stores. EAH can be prevented by insuring that athletes do not drink to excess during exercise, which has been known since 1985.

Hyponatraemic encephalopathy despite a modest rate of fluid intake during a 109 km cycle race.

OBJECTIVE: To report a case of exertional hyponatraemic encephalopathy that occurred despite a modest rate of fluid intake during a 109 km cycling race. METHODS: Men and women cyclists were weighed before and after the race. All subjects were interviewed and their water bottles measured to quantify fluid ingestion. A blood sample was drawn after the race for the measurement of serum Na(+) concentration. RESULTS: From the full set of data (n = 196), one athlete was found to have hyponatraemic encephalopathy (serum [Na(+)] 129 mmol/l). She was studied subsequently in the laboratory for measurement of sweat [Na(+)] and sweat rate. CONCLUSIONS: Despite a modest rate of fluid intake (735 ml/h) and minimal predicted sweat Na(+) losses, this female athlete developed hyponatraemic encephalopathy. The rate of fluid intake is well below the rate currently prescribed as optimum. Drinking to thirst and not to a set hourly rate would appear to be the more appropriate behaviour.

The effects of different air velocities on heat storage and body temperature in humans cycling in a hot, humid environment.

AIM: The purposes of this study were to determine (i) the effects of different facing air velocities on body temperature and heat storage during exercise in hot environmental conditions and (ii) the effects of ingesting fluids at two different rates on thermoregulation during exercise in hot conditions with higher air velocities. METHODS: On five occasions nine subjects cycled for 2 h at 33.0 +/- 0.4 degrees C with a relative humidity of 59 +/- 3%. Air velocity was maintained at 0.2 km h(-1) (0 WS), 9.9 +/- 0.3 km h(-1) (10 WS), 33.3 +/-2.2 km h(-1) (100 WS) and 50.1 +/- 3.2 km h(-1) (150 WS) while subjects replaced 58.8 +/- 6.8% of sweat losses. In the fifth condition, air velocity was maintained at 33.7 +/- 2.2 km h(-1) and subjects replaced 80.0 +/- 6.8% of sweat losses (100.80 WS). RESULTS: Heat storage, body temperature and rating of perceived exertion were higher in 0 and 10 WS compared with all other conditions. There were no differences in any measured variable between 100 and 150 WS, or between 100 and 100.80 WS. Thus, the evaporative capacity of the environment is increased with higher air velocities, reducing heat storage and body temperature. At higher air velocities, a higher rate of fluid ingestion did not influence heat storage, body temperature or sweat rate. CONCLUSION: The finding of previous laboratory studies showing a beneficial effect of high rates of fluid ingestion on thermoregulation during exercise in hot, humid, windstill conditions cannot be extrapolated to out-of-doors exercise in which facing air velocities are seldom lower than the athlete's rate of forward progression.

The effect of pre-exercise cooling on high intensity running performance in the heat.

The purpose of this study was to determine the effect of pre-exercise cooling on high intensity, moderate duration running performance and thermoregulatory responses in a hot environment (38 degrees C, 40 %RH). On separate days, 11 male subjects completed two treadmill runs to exhaustion at 100% of maximal aerobic power with (CL) and without (CT) pre-exercise cooling. Cooling consisted of 20 min of standing rest in a 22 degrees C environment with fan cooling (4.0 m x sec -1) and water spraying (50 ml x min -1) applied to both anterior and posterior body surfaces. Core temperature (T(c)) was determined with an esophageal T(es) probe, and skin temperatures (T(sk)) were measured using surface thermistors positioned at four sites. Finger prick blood samples were taken before and after exercise for the determination of blood lactate. Heart rates and ratings of thermal sensations and comfort were also recorded. Time to exhaustion was significantly shorter in the CL condition (368.9 +/- 56.2) compared to the CT condition (398.8 +/- 55.5 sec). Peak T(es) (37.51 +/- 0.57 vs. 38.56 +/- 0.30 degrees C for CL and CT, respectively), T(sk) (34.18 +/- 1.22 vs. 36.15 +/- 0.70 degrees C for CL and CT, respectively), rates of heat gain (0.20 +/- 0.05 vs. 0.28 +/- 0.05 degrees C x min -1 for CL and CT, respectively), and net heat storage (238.4 +/- 109.6 vs. 531.9 +/- 78.3 kJ for CL and CT, respectively) were all lower in the CL compared to CT throughout the treadmill runs. There were no differences in lactate accumulation between the two conditions. Based on these data, it can be concluded that pre-exercise cooling influences thermoregulatory responses during high intensity, moderate duration exercise; however, performance is impaired compared to a control trial in which no cooling procedures were employed.

The influence of different external cooling methods on thermoregulatory responses before and after intense intermittent exercise in the heat.

The purpose of this study was to determine the effect of different cooling methods on thermoregulation before and after intermittent anaerobic exercise in the heat (38 degrees C). On separate days, 10 men completed 4 conditions consisting of 2 sets of six 30-second sprints (with 30 seconds of rest) at 125% of maximal aerobic power with each set of sprints followed by a cooling procedure. The 4 conditions were the following: passive cooling at room temperature (22 degrees C; PRC), fan cooling (4.0 m x s(-1), 22 degrees C; FAC), fan cooling with water spraying (50 ml x min(-1); FWC), and a noncooling passive recovery in the heat chamber (38 degrees C; PCC). Each set of 6 sprints was followed by a 12-minute cooling period; after the second 12-minute period, cooling continued until esophageal temperature (Tes) was reduced by 1.0 degrees C. Tes and mean skin temperatures (Tsk) were taken before and during exercise and during all cooling phases. Cooling rates (mean +/- SEM) after the second set of sprints (based on Tes) were greater (p < 0.05) in PRC (0.043 +/- 0.007) than in the other conditions (FWC = 0.027 degrees +/- 0.005 degrees, FAC = 0.03 degrees +/- 0.004 degrees, and PCC = 0.021 degrees +/- 0.003 degrees C per minute). Overall decreases in heat content, however, were greater in the FWC (-332.2 +/- 27.8) and FAC (-129.9 +/- 14.7 kJ) conditions compared with the PRC condition (29.0 +/- 14.9 kJ). The time required to lower Tes by 1.0 degrees C with PRC (22.8 +/- 1.8) was less than with FAC (30.4 +/- 2.7 minutes). Finally, the rate of increase in Tes during the second set of sprints was less in the FAC and FWC conditions (0.15 degrees +/- 0.01 degrees and 0.11 degrees +/- 0.01 degrees C per minute) compared with the PCC and PRC conditions (0.19 degrees +/- 0.01 degrees and 0.18 degrees +/- 0.01 degrees C per minute), suggesting differences in pre-exercise cooling. Based on cooling rates and the time required to lower Tes by 1.0 degrees C, PRC was the most effective method of cooling. The conclusion is different, however, when taking into account changes in heat content since the FAC and FWC conditions were more effective in dissipating heat and in preventing heat gain during the second set of sprints

Cerivastatin and gemfibrozil-associated rhabdomyolysis.

OBJECTIVE: To report a case of rhabdomyolysis resulting from concurrent use of cerivastatin and gemfibrozil. CASE SUMMARY An 82-year-old white man presented to the emergency department with severe muscle weakness and inability to walk approximately one month after starting cerivastatin. He had been taking gemfibrozil for several years without any known adverse effects. Both medications were discontinued and the patient recovered. He was discharged with a diagnosis of rhabdomyolysis secondary to his medications. DISCUSSION: Four previous reports describing rhabdomyolysis in patients on concomitant cerivastatin and gemfibrozil have been cited. Although monotherapy with cerivastatin is well tolerated and has a low frequency of adverse events, the combination with nicotinic acid (i.e., niacin) or a fibric-acid derivative (i.e., gemfibrozil, fenofibrate) may result in severe skeletal muscle toxicity and rhabdomyolysis. CONCLUSIONS: According to the Naranjo scale, a probable relationship exists between the concomitant use of gemfibrozil and cerivastatin with the resulting development of rhabdomyolysis. Concurrent use of gemfibrozil and cerivastatin is therefore contraindicated.

The use of arthroscopic thermal capsulorrhaphy to treat internal impingement in baseball players.

PURPOSE: To determine if reducing glenohumeral translation by arthroscopic thermal shrinkage would improve the results of arthroscopic treatment of internal impingement in baseball players. TYPE OF STUDY: Retrospective review. INTRODUCTION: Traditional treatment of internal impingement does not address the pathophysiology. Baseball players' shoulders routinely have glenohumeral laxity. Addressing this laxity by thermal capsulorrhaphy may improve the results in the treatment of these patients. Traditional treatment of labral and rotator cuff debridement and/or repair has had marginal results in regard to the most important criterion, return to competition. METHODS: Charts of all patients undergoing surgical arthroscopy of the shoulder for suspected internal impingement were analyzed. Patients were divided into 2 groups: traditional treatment (non-heat-probe group, NHP, n = 51) or traditional treatment plus thermal capsulorrhaphy (heat-probe group, HP, n = 31). Internal impingement was confirmed by physical examination and arthroscopic criteria. All participants were baseball players and follow-up was 30 months. Data were analyzed for initial return to play and continued participation 30 months after surgery. RESULTS: Mean time for return to competition was 7.2 months in the NHP group and 8.4 months in the HP group; 80% of the NHP group returned to competition compared with 93% of the HP group. At 30 months after surgery, 67% of the NHP group was back to competition compared with 90% of the HP group (P =.01). The HP group averaged 7 degrees less external rotation than before surgery. There were no significant complications in either group. CONCLUSIONS: Thermal capsular shrinkage can be safely used in the treatment of internal impingement in the throwing athlete.