Safety of antiemetic prophylaxis with HTX-019 as a 30-min infusion in patients with cancer: a retrospective study

Aim: The NK-1 receptor antagonist HTX-019 (CINVANTI^® [aprepitant injectable emulsion]) was approved for preventing chemotherapy-induced nausea and vomiting based on bioequivalence studies in healthy volunteers. The objective of this study was to evaluate HTX-019 safety in cancer patients. Patients & methods: This retrospective analysis evaluated the safety of HTX-019 130 mg 30-min intravenous infusion, as part of a three-drug antiemetic regimen. Results: No treatment-emergent adverse events (TEAEs) were deemed related to HTX-019. During treatment cycles, three of 100 patients developed five reversible TEAEs: dyspnea, hot flash, pain, nausea and visual disturbance. Between cycles, six patients had TEAEs of dizziness (three patients), infusion-site events (two patients) and headache (two patients). Conclusion: HTX-019 is safe in cancer patients receiving chemotherapy.

QIM19-138: Care Coordination Between Prescribers and the Specialty Pharmacy—Qualitative Insights Into Designing a Quality Improvement Program for Multisite Community Oncology Practices

Background: There is 1 multiple myeloma (MM) quality metric available (treatment with bisphosphonates, developed by the American Society of Hematology) to evaluate the quality of cancer care delivered to improve patient experience and outcomes. As many community practices integrate specialty pharmacy (SP) services into their practice, patient education, treatment adherence, and visit scheduling coordination are becoming increasingly complex, particularly for treatments with Risk Evaluation and Mitigation Strategies (REMS) programs. We sought to understand the fundamental challenges facing a multisite community oncology practice undergoing SP centralization to identify potential quality gaps for patients with MM. Methods: Structured, in-depth interviews were conducted with physicians treating the highest volume of MM patients across 5 different urban and rural sites of a single multisite community practice. The interviews covered 6 domains: access to care or clinical advice/communication (ACC/AC); care coordination (CC); disease management for MM (DMMM); patient education (PE); medication management (MedMgmt); and data and quality improvement (DQI). Results: Five providers treating 304 MM patients from January 2016 through April 2018 identified several key issues related to the interaction between the SP and clinical sites: ACC/AC, coordination of efforts to ensure patient affordability of both oral/intravenous components; CC, centralize pharmacy workflow processes (specifically REMS enrollment) to ensure timely receipt of medication (high priority); DMMM/PE, inconsistent patient education regarding the role of the centralized pharmacy in the REMS programs, side-effect management, and intent of therapy; MedMgmt, limited concern/understanding of the impact of oral therapy adherence; DQI, no set standards for MM-specific quality measures for benchmarking performance between SP and practices. Conclusions: This qualitative survey identified several areas for improving MM-related quality of care in terms of the relationship between a centralized SP and satellite offices. To address these themes, the practice further integrated licensed practical nurses into the SP. Additionally, 2 quality improvement measurement opportunities were proposed: (1) measuring adherence using pharmacy refill data and (2) overall treatment delay (number of days from prescribing to pick-up/ship to patient).

Characterization of hydrogen responsive nanoporous palladium films synthesized via a spontaneous galvanic displacement reaction

A model is presented regarding the mechanistic properties associated with the interaction of hydrogen with nanoporous palladium (np-Pd) films prepared using a spontaneous galvanic displacement reaction (SGDR), which involves PdCl(2) reduction by atomic Ag. Characterization of these films shows both chemical and morphological factors, which influence the performance characteristics of np-Pd microcantilever (MC) nanomechanical sensing devices. Raman spectroscopy, uniquely complemented with MC response profiles, is used to explore the chemical influence of palladium oxide (PdO). These combined techniques support a reaction mechanism that provides for rapid response to H(2) and recovery in the presence of O(2). Post-SGDR processing via reduction of PdCl(2)(s) in a H(2) environment results in a segregated nanoparticle three-dimensional matrix dispersed in a silver layer. The porous nature of the reduced material is shown by high resolution scanning electron microscopy. Extended grain boundaries, typical of these materials, result in a greater surface area conducive to fast sorption/desorption of hydrogen, encouraged by the presence of PdO. X-ray diffraction and inductively coupled plasma-optical emission spectroscopy are employed to study changes in morphology and chemistry occurring in these nanoporous films under different processing conditions. The unique nature of chemical/morphological effects, as demonstrated by the above characterization methods, provides evidence in support of observed nanomechanical response/recovery profiles offering insight for catalysis, H(2) storage and improved sensing applications.

A retrospective cohort study to assess the impact of therapeutic substitution of darbepoetin alfa for epoetin alfa in anemic patients with myelodysplastic syndrome

Darbepoetin alfa and epoetin alfa are used to treat anemia in the undertreated population of patients with myelodysplastic syndrome (MDS). We implemented guidelines to switch anemic patients with MDS from epoetin alfa 40,000 U weekly to darbepoetin alfa 200 microg every 2 weeks and then conducted a retrospective cohort study of the initial 263 treated patients. Patients (> or = 18 years old, MDS diagnosis) were either previously treated with epoetin alfa (received 16 weeks of prior epoetin alfa and either switched to darbepoetin alfa or remained on epoetin alfa) or treatment-naive (no previous erythropoietin therapy and received only 1 agent for 16 weeks). Both major response and minor response based on the International Working Group criteria were calculated. The study was not powered to statistically compare treatment groups; values presented are for descriptive purposes only. Data from 244 patient records were included: 142 previous epoetin alfa patients (80 switched to darbepoetin alfa, 62 remained on epoetin alfa) and 102 naive patients (56 darbepoetin alfa, 46 epoetin alfa). Major response rates were similar between treatment groups in both the naive (46% for darbepoetin alfa, 35% for epoetin alfa) and previous epoetin alfa groups (26% for darbepoetin alfa, 17% for epoetin alfa). Overall response rates were 42%-76% across treatment groups. No differences in transfusions across groups were observed. Treatment of anemic patients with MDS with either darbepoetin alfa or epoetin alfa appeared to be effective. Whereas epoetin alfa was most frequently administered on a weekly basis, darbepoetin alfa was most frequently administered every 2 weeks, which may offer the benefit of convenience with its less frequent dosing.

Angiotensin-converting enzyme genotype and physical performance during US Army basic training

Prior studies have suggested that angiotensin I-converting enzyme (ACE) genotype correlates with superior physical performance in highly selected populations. This study assessed whether such an association exists in a heterogeneous population. Using polymerase chain reaction techniques, we determined the ACE genotypes (insertion/insertion, deletion/insertion, or deletion/deletion) of 62 male and 85 female US Army recruits. Before and after 8 wk of basic training, we determined peak oxygen uptake and performance on the Army Physical Fitness Test (APFT), which includes standardized measures of muscular endurance (sit-ups, push-ups) and a 2-mile run. Subjects of different ACE genotypes had similar peak oxygen uptakes and APFT scores, both before and after training. Subjects with genotype II had higher APFT scores than others, but the differences were not statistically significant. Furthermore, no ACE genotype group had a performance advantage in analyses that adjusted for baseline fitness. We conclude that ACE genotype does not have a strong effect on aerobic power or muscular endurance in healthy, young American adults drawn from an ethnically and geographically diverse population.

The prevalence of exercise-induced bronchospasm among US Army recruits and its effects on physical performance

STUDY OBJECTIVES

To measure the prevalence of exercise-induced bronchospasm (EIB) and to determine its effect on the physical performance response to training in otherwise healthy young adults.

DESIGN

Observational, retrospective study.

SETTING

Fort Jackson, SC, May to July 1998.

PARTICIPANTS

One hundred thirty-seven ethnically diverse US Army recruits undergoing an 8-week Army basic training course.

MEASUREMENTS AND RESULTS

Subjects underwent exercise challenge testing at the end of basic training to evaluate for EIB (defined as a decrease in FEV(1) of > or = 15%, 1 or 10 min after running to peak oxygen uptake on a treadmill). Those subjects who were unable to run to peak oxygen uptake, or who were unable to perform two baseline FEV(1) maneuvers the results of which were within 5% of each other, were excluded from analysis. We measured peak oxygen uptake on a treadmill and the scores achieved on the components of the US Army physical fitness test (APFT). Of 137 subjects, 121 (58 men and 63 women) met our inclusion criteria. Eight subjects (7%) had EIB. Subjects who experienced EIB and unaffected control subjects both showed statistically significant gains in performance on the APFT events during basic training. At the end of basic training, peak oxygen uptake levels and APFT event scores were not significantly different between subjects with EIB and unaffected control subjects.

CONCLUSIONS

Seven percent of the US Army recruits who were tested had EIB, but this did not hinder their physical performance gains during basic training. EIB per se should not be an absolute reason to exclude individuals from employment in jobs with heavy physical demands.

Risk factors for training-related injuries among men and women in basic combat training

PURPOSE

Past investigations indicate that training-related injuries are associated with certain performance-oriented measures of physical fitness and certain lifestyle characteristics. This study examined associations between injuries, direct (physiological) measures of physical fitness, and lifestyle characteristics.

METHODS

Subjects were 756 men and 474 women performing the standardized activities involved in U.S. Army Basic Combat Training (BCT). Before BCT, a subsample of subjects (182 men and 168 women) were administered a series of tests that included a treadmill running test (peak VO2), dual-energy x-ray absorptiometry (for body composition), several measures of muscle strength, a hamstring flexibility test, and a vertical jump. A questionnaire addressed smoking habits and prior physical activity. All subjects were administered the Army Physical Fitness test consisting of push-ups, sit-ups, and a 3.2-km run. Gender, age, stature, and body mass were obtained from physical examination records. Injuries incurred during BCT were transcribed from medical records; for each medical visit, the diagnosis, anatomical location, disposition (final outcome of visit), and days of limited duty were recorded.

RESULTS

Women had over twice the injury rate of men. For men and women, fewer push-ups, slower 3.2-km run times, lower peak VO2, and cigarette smoking were risk factors for time-loss injury. Among the men only, lower levels of physical activity before BCT and both high and low levels of flexibility were also time-loss injury risk factors. Multivariate analysis revealed that lower peak VO2 and cigarette smoking were independent risk factors for time-loss injury.

CONCLUSIONS

Lower aerobic capacity and cigarette smoking were independently associated with a higher likelihood of injury in both men and women during a standardized program of physical training. Further studies are needed to assess associations between injury and body composition and muscular strength.

Evaluation of anthropometric equations to assess body-composition changes in young women

BACKGROUND

Healthy young women who engage in an exercise program may lose fat that is not reflected in body weight changes because of concurrent gains in fat-free mass (FFM).

OBJECTIVE

This study addressed the question of how well anthropometry-based predictive equations can resolve these changes.

DESIGN

Several widely used skinfold-thickness- or circumference-based equations were compared by using dual-energy X-ray absorptiometry to study 150 healthy young women before and after 8 wk of Army basic combat training (average energy expenditure: 11.7 MJ/d).

RESULTS

Women lost 1.2 +/- 2.6 kg fat (mean +/- SD) and gained 2.0 [corrected] +/- 1.5 kg FFM. Fat loss (r = 0.47), but not FFM gain (r = 0.01), correlated with initial fatness. Thus, for many women who lost fat, body weight did not change or increased. Fat loss was associated with a reduction in abdominal circumference but this alone was not a consistent marker of fat loss. One circumference equation and one skinfold-thickness equation yielded the smallest residual SDs (2.0% and 1.9% body fat, respectively) compared with the other equations in predicting body fat. The sensitivity and specificity of the best equations in predicting changes in percentage body fat were not better than 55% and 66%, respectively.

CONCLUSIONS

These data suggest that for women, anthropometry can provide better estimates of fatness than body mass index but it is still relatively insensitive to short-term alterations in body composition. Not surprisingly, the circumference equation that includes the most labile sites of female fat deposition (ie, waist and hips instead of upper arm or thigh) proved to be the most reliable.

The effects of choline supplementation on physical performance

It has been reported that plasma choline levels decrease following certain types of strenuous exercise. Preliminary findings also suggest that a drop in plasma choline may limit physical performance, while choline supplementation may delay fatigue during prolonged efforts. A double-blind crossover design was used to determine the relationship between plasma choline and performance during and after 4 hr of strenuous exercise. Volunteers (N = 14) received either a placebo or treatment beverage (8.425 g choline citrate) prior to and midway through a 4-hr load carriage treadmill exercise (3% grade at 5.6 km/h 3 20 km) carrying a total load of 34.1 kg. Following the treadmill test, run time-to-exhaustion and squat tests were performed, and perceived exertion, plasma choline, glycerophosphocholine, and phosphatidylcholine were measured. Plasma choline levels increased 128% after the run-to-exhaustion with the choline supplemented beverage but remained unchanged with the placebo beverage. No significant effects were seen with choline supplementation on any outcome performance measure. Consequently, soldiers conditioned to carry heavy loads over long distances do not deplete plasma choline as a result of a prolonged exhaustive exercise under a placebo beverage, nor do they benefit from choline supplementation to delay fatigue under the same conditions.

Acute hormonal responses to a single bout of heavy resistance exercise in trained power lifters and untrained men

The purpose of this study was to investigate the acute responses of both stress and fluid regulatory hormones to a single bout of resistance exercise in both trained and untrained men. Seven competitive power lifters (PL) and 12 untrained subjects (UT) performed one set of the leg press exercise to exhaustion at 80% of their respective one-repetition maximum. Blood samples were obtained twice prior to exercise (at P1 and P2), immediately postexercise (IP), and at 5 minutes postexercise (5PE). Compared to P1 and P2, plasma epinephrine, norepinephrine, dopamine, atrial peptide, osmolality, and blood lactic acid increased significantly (p < or = 0.05) at IP. Plasma epinephrine, norepinephrine, atrial peptide, and blood lactic acid concentrations remained elevated at 5PE compared to P1 and P2. Plasma renin activity and angiotensin II were significantly elevated at 5PE compared to P1, P2, and IP, and this increase was significantly greater in PL compared to UT at 5PE. These data indicate that an acute bout of resistance exercise dramatically affects secretion of stress and fluid regulatory hormones.

Phylogenetic characterization of a highly attenuated strain of equine arteritis virus from the semen of a persistently infected standardbred stallion

An avirulent, novel variant of equine arteritis virus (EAV; CA95G) was isolated from the semen of a persistently infected Standardbred stallion. The CA95G virus caused subclinical infection and seroconversion in susceptible horses, and virus was isolated only once from blood and nasal secretions collected from 6 experimentally infected horses. Sequence analysis of genes encoding the known EAV structural proteins shows that this highly attenuated strain of EAV is genetically similar to virulent field strains of EAV and, in particular, to a strain of EAV that was isolated during an outbreak of equine viral arteritis in western Canada in 1986. Not only is the carrier stallion the critical natural reservoir of EAV, but genetic diversity of the virus is generated in the course of persistent infection of carrier stallions. The subtle genetic changes that facilitate and maintain persistent EAV infection of the stallion's reproductive tract likely influence phenotypic properties of the virus such as virulence.

Passive transfer, rate of decay, and protein specificity of antibodies against equine arteritis virus in horses from a Standardbred herd with high seroprevalence

OBJECTIVE

To determine rate of decay of passively acquired antibodies in Standardbred foals on a farm with a high seroprevalence to equine arteritis virus (EAV) and to determine whether vertical or horizontal transmission of the virus was responsible for infection on the farm.

DESIGN

Repeated-measures study.

ANIMALS

46 Standardbred horses (15 brood mares and their foals, 5 stallions, and 11 young horses).

PROCEDURE

Serum samples obtained from horses on the farm were evaluated by serum neutralization and western immunoblot analysis to detect EAV-specific antibodies. The half-life of passively acquired antibodies in foals was estimated by use of regression analysis.

RESULTS

Most (14/15) of the mares evaluated were seropositive to EAV. After suckling, their foals were also seropositive. Mean biological half-life for passively acquired antibodies in serum samples obtained from foals was 32 days (r2 = 0.61). The foal born to a seronegative dam and all 11 young horses from the farm were seronegative to EAV. At least 2 of 5 stallions on the farm were persistently infected carriers that were shedding virus in their semen. Immunoblot analysis of seropositive serum samples most consistently recognized the M protein of EAV.

CLINICAL IMPLICATIONS

Analysis of these data indicated that a modified-live EAV vaccine can be administered to foals after they are 8 months old without risk of interference from maternal antibodies, regardless of serologic status of the foal's dam. Horizontal transmission of EAV via the respiratory tract apparently was uncommon on the farm, indicating that mares primarily were infected by venereal transmission of virus from carrier stallions.

Serologic response of horses to the structural proteins of equine arteritis virus

Equine arteritis virus (EAV) is the causative agent of equine viral arteritis, an apparently emerging disease of equids. In this study, the antibody response of horses to the structural proteins of EAV was evaluated using gradient-purified EAV virions and baculovirus-expressed recombinant EAV structural proteins (G(L), G(S), M, N) as antigens in a Western immunoblotting assay. Thirty-three sera from horses that previously had been naturally or experimentally infected with EAV were evaluated, including samples from mares, geldings, and both persistently and nonpersistently infected stallions. Sera also were evaluated from 4 horses that had been vaccinated with the commercial modified live EAV vaccine. The data suggest that the serologic response of individual horses to EAV may vary with the infecting virus strain and duration of infection. The M protein was most consistently recognized by the various serum samples, whereas the response to the N and G(L) proteins was variable and the G(S) protein was bound by only 1 serum sample. The immunoblotting assay definitively established the protein specificity of the humoral response of horses to EAV; however, it clearly is less sensitive than the standard serum neutralization (SN) test--2 of the 37 sera that were seropositive by the SN test failed to react in the immunoblot assay with any EAV structural protein. Furthermore, the G(L) protein expresses the known neutralization determinants of EAV, yet only 22 of the 37 sera that had SN antibodies bound the G(L) protein in the immunoblotting assay. Information from this study will assist ongoing efforts to develop improved methods for the serologic diagnosis of EAV infection of horses.

Comparison of body composition assessment among lean black and white male collegiate athletes

Variations in the density of the fat-free mass (DFFM) across ethnic groups is a critical factor that invalidates the use of body fat equations. It has also been suggested that resistance trained athletes may have higher body densities (BDs) than untrained subjects. Thus, the validity of using anthropometric (ANT) equations, which have mainly been derived on white nonathletic groups, has been questioned for athletic white and black men. This study compared BD and percent body fat (%BF) between 34 white (20 +/- 1 yr, 184 +/- 11 cm, 84 +/- 12 kg, 25 +/- 3 BMI) and 30 black (20 +/- 1 yr, 182 +/- 9 cm, 84 +/- 12 kg, 25 +/- 2 BMI) male collegiate athletes and determined the accuracy of 5 ANT equations in estimating %BF. Subjects were underwater weighed (UWW), and skinfold measurements were obtained from the chest, mid-axillary, abdomen, suprailiac, subscapula, triceps, and thigh. BD was obtained from UWW and estimated from the five skinfold equations. From UWW, significant (P < or = 0.05) differences were found for BD (1.075 +/- 0.007 vs 1.0817 +/- 0.009), but not for %BF (10.49 +/- 2.8 vs 11.59 +/- 3.4) for white and black subjects, respectively. Differences were noted for subcutaneous skinfold sites (abdominal (vertical), suprailiac, and thigh), sum of three and seven skinfolds, and proportion of subscapular subcutaneous fat. One out of five and five out of five ANT equations (Siri conversions) yielded significantly lower estimates compared with UWW %BF for the white and black athletes, respectively. Use of the Schutte equation for the black athletes resulted in overpredictions of %BF for five out of five equations. In addition, the Schutte equation offered slightly greater accuracy than did the Siri equation for estimating %BF in black athletes. These data confirm earlier concerns that ANT equations derived on general populations may not be as accurate for athletic populations and also suggest that correction equations are necessary for converting BD into %BF for populations differing with respect to race or training status.

Gender comparison of peak oxygen uptake: repetitive box lifting versus treadmill running

The gender differences in peak oxygen uptake (VO2peak) for various modes of exercise have been examined previously; however, no direct gender comparisons have been made during repetitive lifting (RL). In the present study the VO2peak between RL and treadmill running (TR) was compared between 20 men [mean (SD) age, height, body mass and body fat: 21 (3) years, 1.79 (0.06) m, 81 (9) kg, 19 (6)%, respectively] and 20 women [mean (SD) age, height, body mass and body fat: 21 (3) years, 1.63 (0.05) m, 60 (7) kg, 27 (6)%, respectively]. VO2peak (l x min[-1]), defined as the highest value obtained during exercise to volitional fatigue, was determined using discontinuous protocols with treadmill grade or box mass incremented to increase exercise intensity. For RL VO2peak, a pneumatically driven shelf was used to lower a loaded box to the floor, and subjects then lifted the box, at a rate of 15 lifts x min(-1). VO2peak (l x min(-1) and ml x kg(-1) x min[-1]) and minute ventilation (VE, l x min[-1]) were determined using an on-line gas analysis system. A two-way repeated measures analysis of variance revealed significant gender effects, with men having higher values for VO2peak (l x min(-1) and ml x kg(-1) x min[-1]) and VE, but women having higher values of the ventilatory equivalent for oxygen (VE/VO2). There were also mode of exercise effects, with TR values being higher for VO2peak (l x min(-1) and ml x kg(-1) x min[-1]) and VE and an interaction effect for VO2peak (l x min(-1) and ml x kg(-1) x min[-1]) and VE/VO2. The women obtained a greater percentage (approximately 84%) of their TR VO2peak during RL than did the men (approximately 79%). There was a marginal tendency for women to decrease and men to increase their VE/VO2 when comparing TR with RL. The magnitude of the gender differences between the two exercise modalities appeared to be similar for heart rate, VE and R, but differed for VO2peak (l x min(-1) and ml x kg(-1) x min[-1]). Lifting to an absolute height (1.32 m for the RL protocol) may present a different physical challenge to men and women with respect to the degree of involvement of the muscle groups used during lifting and ventilation.

Physical performance and metabolic recovery among lean, healthy men following a prolonged energy deficit

Previous studies have demonstrated that full recovery from weight loss may take months or years. The present investigation examined short-term recovery (5 wks "post") of physical performance (muscular strength, muscular power, vertical jump), body composition, metabolic hormones (testosterone, luteinizing hormone, sex hormone binding globulin, insulin-like growth factor-1, triiodothyronine, thyroxine, thyroid binding globulin, and thyroid-stimulating hormone) and metabolic markers (transferrin, ferritin, prealbumin, glycerol, nonesterified fatty acids, high-density lipoproteins, and lactate) in 10 healthy young men after an 8-week Army course with an energy deficit (1000 kcal/d) and loss of body mass (-12%). Subjects ate ad libitum after the course ended ("post"). Body composition was determined by dual-energy X-ray absorptiometry; strength from a simulated power clean, power from body mass and jump height, and metabolic hormones were measured in morning-fasted blood by radioimmunoassay. With the exception of transferrin and glycerol, all study parameters were significantly (p<.05) altered by the training course. At 5 weeks post fat-free mass along with all physical performance measures returned to initial levels; however, fat mass had significantly (p<.05) increased over initial levels. Also, with the exception of lactate, all measured hormones and markers were close to initial levels and within normal ranges. Reported complications during recovery included sleep irregularities, diarrhea, loss of motivation and feelings of fatigue. While the long range effect of this energy deprivation experience is uncertain, these data do suggest that severe weight loss does not result in lasting alterations of the contractile and metabolic properties of skeletal muscle in young, lean, healthy men.

Neutralization determinants of laboratory strains and field isolates of equine arteritis virus: identification of four neutralization sites in the amino-terminal ectodomain of the G(L) envelope glycoprotein

The N-terminal hydrophilic ectodomain of the G(L) envelope glycoprotein of equine arteritis virus (EAV) contains neutralization determinants of the virus. We developed a panel of 17 neutralizing murine monoclonal antibodies (MAbs) to further characterize the neutralization determinants of EAV. Included were 6 MAbs previously raised against a laboratory strain (EAVUCD) of the original Bucyrus strain of EAV, as well as 11 additional MAbs that were raised against a neutralization-resistant variant [escape mutant (EM)] virus (EM6D10) that was derived from EAVUCD. All MAbs raised against EAVUCD and 4 of the MAbs raised against EM6D10 (2B3, 5F8, 8D4, and 10B4) reacted with the corresponding G(L) envelope glycoprotein in a Western immunoblotting assay, whereas the remaining 7 MAbs raised against EM6D10 did not react with any viral protein in the immunoblotting assay but competitively inhibited the binding of MAbs 2B3, 5F8, 8D4, and 10B4, indicating that they also recognize epitopes on the G(L) protein. A panel of 18 EM viruses raised to the MAb panel, 19 field isolates of EAV from North America and Europe, the modified-live virus vaccine (ARVAC), and 3 other laboratory strains of EAV were characterized by microneutralization assay with the panel of neutralizing MAbs and polyclonal rabbit and horse antisera. Comparative analysis of the nucleotide sequences of ORF5 and the deduced amino acid sequences of the G(L) protein of individual EM viruses and field isolates of EAV identified four distinct neutralization sites. These sites include amino acids 49 (site A), 61 (site B), 67 through 90 (site C), and 99 through 106 (site D). With the notable exception of site A, the sites were all located in the V1 variable region (amino acids 61-121) within the second half of the N-terminal hydrophilic ectodomain of the G(L) protein. Site D includes several overlapping linear epitopes which appear to interact with amino acids in the other three sites to form conformationally dependent epitopes. Amino acid substitutions within any of these four sites can alter the neutralization phenotype of individual strains of EAV.

Isolation of a poxvirus from a black-tailed deer (Odocoileus hemionus columbianus)

A poxvirus was isolated during the latter half of 1993 from a black-tailed deer (Odocoileus hemionus columbianus) that died of fulminant adenovirus infection in California (USA). The poxvirus was isolated from a pooled tissue homogenate, after repeated serial blind passages in primary black-tailed deer testicular cells. Based on electron microscopic examination of the virus, we observed morphologic features typical of the genus Orthopoxvirus, although definitive characterization was not done.

Regional fat placement in physically fit males and changes with weight loss

The abdomen is the principal site of fat deposition in men, and because abdominal fat is readily mobilized during exercise, the relative proportion of fat in the abdominal site may negatively correlate with the amount of regular physical activity, and even with physical fitness. This study presents data for regional fatness in 165 fit young men (U.S. Army Ranger candidates; initial body fat = 14.7 +/- 4.7%) assessed by dual-energy x-ray absorptiometry (DEXA), and for relative changes occurring following a 13% weight loss produced by a 1000 kcal.d-1 energy deficit over 8 wk. Fat-free mass was constant across quintiles of percent body fat; only fat mass was different (16.2 +/- 2.2 kg and 6.0 +/- 1.4 kg at upper and lower quintiles, respectively). Truncal fat accounted for about 41% of total body fat in all quintiles; only the proportion of fat distributed to the arms was significantly higher in the fattest quintiles of men. Among a group of less intensely trained soldiers with the same average fatness as the highest quintile of Ranger students (20%), relative fat distribution to the trunk approached 50% of the total fat. Following weight loss, Ranger students lost half of the fat in all regions assessed (legs, arms, and trunk). The only significant association between regional losses and initial fatness was a greater proportion of fat lost from the arms in the fattest Rangers. These data suggest a "fit fat" distribution in active young men in which fat remains in the arms and legs until extreme weight loss occurs and the metabolically more active abdominal fat approaches depletion.

Susceptibility of Culicoides variipennis sonorensis to infection by polymerase chain reaction-detectable bluetongue virus in cattle blood

Cattle bloods containing only polymerase chain reaction (PCR)--detectable bluetongue-10 viral nucleic acid, but as determined by virus isolation techniques, not bluetongue-10 virus, were incapable of infecting intrathoracically inoculated Culicoides variipennis sonorensis. These insects also failed to transmit bluetongue-10 virus when fed on sheep. Cattle whose blood contain only PCR-detectable bluetongue viral nucleic acid, but no infectious virus, are unlikely to play a role in the epidemiology of bluetongue. The biological significance of PCR-based detection assays and their effect on animal health regulations on the international trade of livestock and livestock germplasm is discussed. Bluetongue virus infection provides a very useful model with which to study arthropod-transmitted RNA virus infections of humans and other animals.

Systemic adenovirus infection associated with high mortality in mule deer (Odocoileus hemionus) in California

Seventeen counties in northern California experienced epizootics of high mortality in the mule deer (Odocoileus hemionus) population during the latter half of 1993. Thirteen deer submitted to the California Veterinary Diagnostic Laboratory System as part of this natural die-off had systemic adenovirus infection. Pulmonary edema was present in all 13 deer. Erosions, ulceration, and abscessation of the upper alimentary tract occurred in 7/13 deer. Four of 13 deer had hemorrhagic enteritis. All 13 deer had widespread systemic vasculitis with endothelial intranuclear inclusions. Fluorescein isothiocyanate-labeled antibody directed against bovine adenovirus type 5 bound to antigen in endothelial cells. Adenovirus was identified by transmission electron microscopy within the nuclei of endothelial cells in 6/6 deer examined. An adenovirus was isolated from lung homogenates of one deer that were cultured on black-tailed deer pulmonary artery endothelial cells. With the exception of the intranuclear inclusions evident on histologic evaluation, gross and histologic changes were similar to those described for bluetongue virus infection and epizootic hemorrhagic disease virus infection in white-tailed deer. Nine additional deer were emaciated and had pharyngeal abscesses with focal vasculitis, which may represent the chronic affects of previous nonfatal adenovirus infection.

Combination cisplatin and carboplatin in advanced squamous cell carcinoma of the head and neck

Twenty-three patients with advanced squamous cell carcinoma of the head and neck who had received no prior chemotherapy were treated with carboplatin 350 mg/m2 followed by cisplatin 50 mg/m2 every 28 days. Twenty-one of 23 patients were evaluable for response and toxicity. Eight patients (38%) achieved complete response (CR) or partial response (PR) with 2 CR and 6 PR. The overall median survival was 8.4 months (range 19 days-56+ months). The major toxicity was hematological with grade III/IV granulocytopenia in 32% and grade III/IV thrombocytopenia in 32%. There was very little nonhematological toxicity and no nephrotoxicity. There were no therapy-related deaths. The combination carboplatin/cisplatin is tolerable in patients with squamous cell carcinoma of the head and neck, with objective responses in 38%; however, the response rate was not superior to single-agent carboplatin or cisplatin. Further studies with a higher dose of cisplatin should be considered.

Compatibility of high-intensity strength and endurance training on hormonal and skeletal muscle adaptations

Thirty-five healthy men were matched and randomly assigned to one of four training groups that performed high-intensity strength and endurance training (C; n = 9), upper body only high-intensity strength and endurance training (UC; n = 9), high-intensity endurance training (E; n = 8), or high-intensity strength training (ST; n = 9). The C and ST groups significantly increased one-repetition maximum strength for all exercises (P < 0.05). Only the C, UC, and E groups demonstrated significant increases in treadmill maximal oxygen consumption. The ST group showed significant increases in power output. Hormonal responses to treadmill exercise demonstrated a differential response to the different training programs, indicating that the underlying physiological milieu differed with the training program. Significant changes in muscle fiber areas were as follows: types I, IIa, and IIc increased in the ST group; types I and IIc decreased in the E group; type IIa increased in the C group; and there were no changes in the UC group. Significant shifts in percentage from type IIb to type IIa were observed in all training groups, with the greatest shift in the groups in which resistance trained the thigh musculature. This investigation indicates that the combination of strength and endurance training results in an attenuation of the performance improvements and physiological adaptations typical of single-mode training.

Energy cost of wearing chemical protective clothing during progressive treadmill walking

While chemical protective (CP) clothing is known to adversely affect physical performance, few data exist regarding the physiological response of wearing US military CP clothing during incremental, dynamic exercise. To quantify the effects of CP clothing on energy cost and to test the hypothesis that the mask contributes little to this effect, oxygen uptake (VO2) and ventilation (VE) were determined in 14 male soldiers who walked on a treadmill at 1.56 m.s-1 for 20 min each at 0, 5, and 10% grades in three clothing conditions: BDU (battledress uniform only), MASK (BDU + M-17 protective mask), and CP clothing (MASK + overgarment, gloves and boots). In BDU's, exercise intensities expressed as %VO2max were 29, 42, and 59% at the three grades, respectively. VO2 was significantly (p < 0.01) greater at all grades (range 13 to 18%) in CP clothing compared to BDU. However, no differences in VO2 were seen between BDU and MASK at any level of exercise. VE was significantly higher at the two highest grades in CP clothing compared to BDU but when expressed relative to VO2 (VE/VO2) was significantly lower at 0% and 5% grades but not at 10%. In the MASK condition, VE was significantly lower at the 10% grade and VE/VO2 was significantly lower at all grades compared to BDU. The results show that despite the mask induced hypoventilation, VO2 is unaffected at exercise intensities up to 60% of VO2max.(ABSTRACT TRUNCATED AT 250 WORDS)

Lower and upper body anaerobic performance in male and female adolescent athletes

Little data exist for upper and lower body mechanical power capability of adolescent athletes. This study compared arm (A) and leg (L) anaerobic peak and mean power (PP and MP) of 20 male and 20 female adolescent athletes after normalization for body mass (BM), fat-free mass (FFM), and lean A and L cross-sectional area (CSA). Power outputs were assessed by the Wingate anaerobic test. FFM and CSA were estimated via anthropometry. No significant (P > 0.05) differences existed between the sexes in Tanner sexual maturity, chronological age, or overall training activity. Males had higher (P < 0.001) absolute PP (W) (L 694 vs 442; A 494 vs 309) and MP (L 548 vs 307; A 337 vs 214). Ratio normalization and ANCOVA were used to remove the influence of body size differences. Ratio normalization showed that males had greater leg PP/BM, MP/BM, MP/FFM, MP/CSA, as well as arm PP/BM and MP/BM, whereas all leg and arm PP and MP ANCOVA adjusted means for BM, FFM, and CSA, except arm MP adjusted for FFM, were significantly (P < 0.01) higher for males than females. We conclude that factors other than muscle mass, possibly qualitative in nature, are responsible for the sex difference in anaerobic performance of adolescent athletes.

Serum lactate dehydrogenase and platelet count predict survival in thrombotic thrombocytopenic purpura

A significant number (some 20%) of patients with thrombotic thrombocytopenic purpura do not respond to standard therapy and die. We reasoned that early identification of those who are likely to fail standard therapy would allow the rational introduction of other treatment modalities. To this end we prospectively evaluated 27 consecutive patients, examining serum LDH levels and platelet counts as markers of disease activity and as predictors of outcome. All patients were treated, according to a written protocol, with high volume plasma exchange (35 ml/kg), prednisone, aspirin, and persantine. Twenty-one of the 27 patients (78%) are alive following therapy. Initial LDH and platelet values did not distinguish between the survivors and nonsurvivors. However, by day 3 of therapy both LDH levels and platelet counts differed significantly between the two groups. Mean day 3 LDH level for survivors was 364 units/L, and for nonsurvivors, 891 units/L (P < 0.005). Mean day 3 platelet count for survivors was 119,000/microL, and for nonsurvivors, 46,000/microL (P < 0.005). Receiver Operator Characteristic curves were constructed and assessed by calculating the area under the curve. This analysis showed that LDH is able to discriminate survivorship one day earlier than platelet count. Both LDH level and platelet count are excellent predictors of survival, under standard therapy, after 3 days of treatment. Early identification of those at greatest risk will facilitate the early institution and evaluation of alternative methods of treatment, such as splenectomy, intravenous Ig, or Vincristine.

Serologic detection of bluetongue virus infection of black-tailed deer: comparison of serum neutralization, agar gel immunodiffusion, and competitive ELISA assays

Three adult black-tailed deer (Odocoileus hemionus columbianus) and four fawns were inoculated with bluetongue virus (BTV) serotype 10 or 17, or epizootic hemorrhagic disease virus (EHDV) serotype 1. Animals were bled at irregular intervals thereafter and the presence of virus-specific antibodies in serum determined by agar gel immunodiffusion (AGID), serum neutralization (SN) and competitive enzyme-linked immunosorbent assay (C-ELISA) tests. Serum antibodies to BTV were detected in all three tests for 692 days after inoculation (DAI) of adult deer, but both the SN and AGID tests gave either erroneous or misleading results. Serum from one deer was negative by the AGID test at 409 DAI with BTV-10 but was positive at 248 and 692 DAI; also one adult and one fawn had antibodies by the SN test to serotypes of BTV with which they were not inoculated. The AGID test for EHDV had false positive results with some sera from animals inoculated only with BTV, and it consistently had false negative results with serum samples collected from an EHDV-inoculated deer at 140 DAI and thereafter. The C-ELISA was the most useful test for the detection of antibodies to BTV because it rapidly gave quantitative and accurate results.

Physiological responses to prolonged treadmill walking with external loads

Limited information is available regarding the physiological responses to prolonged load carriage. This study determined the energy cost of prolonged treadmill walking (fixed distance of 12 km) at speeds of 1.10 m.s-1, 1.35 m.s-1, and 1.60 m.s-1, unloaded (clothing mass 5.2 kg) and with external loads of 31.5 and 49.4 kg. Fifteen male subjects performed nine trials in random order over a 6-week period. Oxygen uptake (VO2) was determined at the end of the first 10 min and every 20 min thereafter. A 10-min rest period was allowed following each 50 min of walking. No changes occurred in VO2 over time in the unloaded condition at any speed. The 31.5 and 49.4 kg loads, however, produced significant increases (ranging from 10 to 18%) at the two fastest and at all three speeds, respectively, even at initial exercise intensities less than 30% VO2max. In addition, the 49.4 kg load elicited a significantly higher (P less than 0.05) VO2 than did the 31.5 kg load at all speeds. The measured values of metabolic cost were also compared to those predicted using the formula of Pandolf et al. In trials where VO2 increased significantly over time, predicted values underestimated the actual metabolic cost during the final minute by 10-16%. It is concluded that energy cost during prolonged load carriage is not constant but increases significantly over time even at low relative exercise intensities. It is further concluded that applying the prediction model which estimates energy expenditure from short-term load carriage efforts to prolonged load carriage can result in significant underestimations of the actual energy cost.

Effects of high-intensity cycle exercise on sympathoadrenal-medullary response patterns

Plasma proenkephalin peptide F immunoreactivity and catecholamines were examined on separate days in nine healthy males before and after maximal exercise to exhaustion at four intensities [36, 55, 73, and 100% of maximal leg power (MLP)] by use of a computerized cycle ergometer. The mean duration of 36, 55, 73, and 100% MLP was 3.31, 0.781, 0.270, and 0.1 min, respectively. All intensities were greater than those eliciting peak O2 uptake for the individual subjects. Blood samples were obtained before, immediately after exercise, and 5 and 15 min after exercise. Significant (P less than 0.05) increases in plasma peptide F immunoreactivity (i.e., from mean resting value of 0.18 to 0.43 pmol/ml) were observed immediately after exercise at 36% MLP. Significant increases in plasma epinephrine were observed immediately after exercise at 36% MLP (i.e., from mean resting value of 2.22 to 3.11 pmol/ml) and 55% MLP (i.e., from mean resting value of 1.67 to 2.98 pmol/ml) and 15 min after exercise at 100% MLP (i.e., from mean resting value of 1.92 to 3.88 pmol/ml). Significant increases for plasma norepinephrine were observed immediately after exercise (36, 55, 73, and 100% MLP), 5 min after exercise (36, 55, and 73% MLP), and 15 min after exercise (36% MLP). Increases in whole blood lactate were observed at all points after exercise for 36, 55, and 73% MLP and 5 min after exercise for 100% MLP. These data show that brief high-intensity exercise results in differential response patterns of catecholamines and proenkephalin peptide F immunoreactivity.

Factors in maximal power production and in exercise endurance relative to maximal power

The relationship of muscle fiber type and mass to maximal power production and the maintenance of power (endurance time to exhaustion) at 36%, 55%, and 73% of maximal power was investigated in 18 untrained but physically active men. Power output was determined at constant pedalling rate (60 rev.min-1) on a cycle ergometer instrumented with force transducers and interfaced with a computer. Maximal power was determined for each subject as the highest one-revolution average power. Fat-free mass was determined by hydrostatic weighing, fat-free thigh volume by water displacement and skinfold measurement, and percentage and area of type II fibers from biopsy specimens taken from the vastus lateralis. Maximal power averaged 771 +/- 149 W with a range of 527-1125 W. No significant correlations were found among percentage of type II fibers, relative area of type II fibers, or fat-free thigh volume and maximal power or endurance times to exhaustion at any percentage of maximal power. Weak but significant relationships were found for fat-free mass with both maximal power (r = 0.57) and endurance time at 73% of maximal power (r = -0.47). These results show maximal power to be more dependent on factors related to body size than muscle-fiber characteristics. The low correlations for so many of the relationships, however, suggest that individuals employ either different combinations of these factors or utilize other strategies for the generation of high power.

A false-positive edrophonium test in a patient with a brainstem glioma

We report a photographically documented false-positive edrophonium test in a patient with a histologically verified brainstem glioma. While a positive response to intravenous edrophonium should usually be regarded as confirmatory for myasthenia gravis, the possibility of a false-positive test must be considered in patients with atypical physical findings.

Hypothalamic-pituitary-adrenal responses to short-duration high-intensity cycle exercise

beta-Endorphin (beta-EP), adrenocorticotropin (ACTH), and cortisol plasma concentrations were examined before and after maximal exercise at four intensities [36, 55, 73, and 100% of maximal leg power (MLP)] by means of a computerized cycle ergometer. All intensities were greater than those eliciting peak O2 uptake for the individual subjects. Blood samples were collected at rest, immediately after exercise, and at 5 and 15 min postexercise. Significant (P less than 0.05) increases were observed at 36% MLP for beta-EP and ACTH immediately after exercise and at 5 and 15 min postexercise. Plasma cortisol increased at 36% MLP at 15 min postexercise. Blood lactate significantly increased at all postexercise collection points for exercise intensities of 36, 55, and 73% MLP and at 5 min postexercise for 100% MLP. beta-EP concentrations at 36% MLP were significantly correlated (r = 0.75) with capillary density (mm-2), and cortisol concentrations at 36% MLP were significantly correlated (r = 0.89) with percentage of type II muscle fibers. No other significant relationships were observed. These data show that brief, high-intensity exercise up to maximal power production results in a nonlinear response pattern in peripheral blood hormone concentrations. Furthermore, blood lactate levels do not appear to be related to hypothalamic-pituitary-adrenal hormone plasma concentrations at high exercise intensities.

Exercise endurance time as a function of percent maximal power production

To develop and validate a mathematical model of the relationship between endurance time (T) and power production, 15 male subjects were first tested for maximal power on an instrumented cycle ergometer at 60 rpm. On subsequent days, they were tested for T at various percentages of maximal power. Curves of T as a function of percent maximal power were curvilinear, and could be made to overlap among subjects by individual abscissa scaling, which resulted in the appearance of horizontal stretching or compression of the curves. The degree of stretching-compression was defined by a statistically obtained scaling factor (F) which served to quantify each subject's endurance ability at fractions of maximal power. F was used to transform percent of maximal power to a scaled power variable (Psc). A curve of the form T = a(Psc)b was developed on 10 of the subjects and validated on the remaining five. Correlation between predicted and actual T was 0.967 for the fitting group and 0.980 for the validation group. A maximal power test and a single endurance test at 40 to 50% of maximal power were found to establish individual endurance-power curves fairly well, with a correlation of 0.828 between actual and predicted T. The combination of F and maximal power for a given physical activity provide a useful profile of an individual's ability to perform at constant exercise intensity.

Upper and lower body anaerobic power: comparison between biathletes and control subjects

This study compared power outputs (PO) from both the upper body (UB) and lower body (LB) Wingate tests of anaerobic power between biathletes and control subjects. Ten biathletes (B) selected by the British Ski Federation for potential assignment to the British team and 13 control (C) subjects cranked or pedaled the same Bodyguard ergometer at maximal RPMs for 30 s against resistances of 2.94 and 4.41 J/rev/kg body weight (BW), respectively. POs were calculated in watts (W) and expressed as peak power (PP, highest 5-s interval), mean power (MP, the mean for 30 s), and power decrease (PD, difference between PP and lowest 5-s PO divided by time). Absolute PP and MP for both UB and LB did not differ between groups. A comparison of POs made relative to BW showed B to have higher values than C: 11.25 vs 10.25 W/kg for LB PP (P less than .05) and 9.21 vs 7.96 W/kg for LB MP (P less than .001). The data expressed relative to kg fat free mass (FFM) showed only MP to be significantly greater in B compared with C (P less than .001). Similar PO relationships were found for the UB where PP (P less than .01) and MP (P less than .001) expressed per kg BW and MP (P less than .001) expressed per kg FFM were higher for B than C. Concomitantly, PD was lower in B than C for both the UB (P less than .05) and LB (P less than .01).(ABSTRACT TRUNCATED AT 250 WORDS)

An evaluation of tests of anaerobic power

The objectives of this study were to examine the relationships between two recently developed laboratory tests of anaerobic power (AnP) and to compare these tests to other measures of AnP. Fifteen male subjects, aged 20-34 years, performed: a 30-s maximal cycle ergometer test (Wingate test), a 60-s isokinetic knee extension test (isokinetic endurance test), a 50-m sprint, a 200-m sprint, and the Margaria stair-climb test. Significant correlations ranging from 0.52-0.76 were found between the Wingate and isokinetic endurance tests for peak and mean values of power and torque, respectively. Indices from both these tests also correlated significantly with the other tests of AnP. The best single index was mean power from the Wingate test, which had correlations of -0.79, -0.82, and 0.74 with the 50-m and 200-m sprint times and the Margaria test, respectively. The data suggest that both the Wingate and isokinetic endurance tests represent valid laboratory tests for evaluating high-intensity, short-term exercise in which the muscle is primarily dependent upon anaerobic processes for energy release.

Effects of sustained manual work and partial sleep deprivation on muscular strength and endurance

In a military field artillery trial, the effects of 8 days of sustained manual work and partial sleep loss on isometric right hand grip strength and upper and lower body anaerobic power (using the Wingate test) was investigated in 25 healthy young male soldiers. During the trial, the physical activity of each subject was essentially identical except that an experimental group (n = 18) manually handled a large quantity of artillery shells (weighing 45 kg) and charges (13 kg), whilst a control group (n = 7) merely simulated manual handling activities and did no lifting or loading of shells. The daily amount of sleep obtained by each group was similar (3 to 4 hours), as were their activity patterns and food and fluid intake. Isometric right hand grip strength for both groups fell progressively during the trial and did not return to pre-trial levels during 3 days of recovery. At the end of the 8 day trial, there were statistically significant reductions in the body weight (1.9%, p less than 0.001), % body fat (7.1%, p less than 0.001) and upper body mean power (7.3%, p less than 0.01) of the experimental group but not in the controls. Lower body peak and mean power were significantly increased at the end of the trial in both the experimental (14.7%, p less than 0.001 and 17.0%, p less than 0.001 respectively) and control (14.3%, p less than 0.01 and 15.0%, p less than 0.05 respectively) groups. Lower body power decrease was significantly increased (18.1%, p less than 0.05) in the experimental group but not in the controls.(ABSTRACT TRUNCATED AT 250 WORDS)

Comparative anaerobic power of men and women

The purpose of this study was to determine the differences in anaerobic power (AnP) between men and women and the contribution of anthropometric variables in accounting for these differences. There were 18 female and 19 male subjects who performed the 30-s Wingate test where power outputs in watts are expressed as mean power (MP, the mean for 30 s) and peak power (PP, the highest 5-s interval). Thigh volume (TV), lean body mass (LBM) and body weight (BW) were used as anthropometric variables. Absolute AnP of men was 35% and 40% higher (p less than 0.001) than that of women for PP and MP, respectively. These differences decreased to 10% and 17% for PP and MP when expressed relative to kg LBM. Anthropometric variables explained less than 50% of the variation in PP and MP for men, while in women, TV accounted for 66% and 71% of the variation in PP and MP, respectively. When the data were combined, TV, BW, and LBM explained 48%, 74%, and 79% of variation in MP and 53%, 71%, and 76% in PP, respectively. These data show that gender differences in indices of AnP are similar to those reported for muscular strength and aerobic power. Additionally, a larger portion of the between gender variation compared to the within gender variation in AnP can be accounted for by anthropometric variables.

An analysis of aerobic capacity in a large United States population

This study presents a description of aerobic capacity in a large US population comprised of 1,514 men and 375 women. Such influencing factors as age, training state, occupation, and body composition were evaluated. The population consisted of new recruits entering the US Army from civilian life as well as soliders in a variety of assignments and physical training programs. Age ranged from 17 to 55 yr. With the exception of one older group, aerobic capacity was determined as maximal O2 uptake measured directly by the Douglas bag technique during a standard discontinuous treadmill running procedure. New male and female recruits representing a young civilian population entered the service with maximal O2 uptake of 51 and 37 ml X kg body wt-1 X min-1, respectively, and thereafter increased 5% during initial basic training. The difference between genders, 30% on an absolute basis, was 14% when expressed as a function of fat-free weight. Aerobic capacity was less after occupational training and continued to decrease with age at an average yearly rate of 10%, or 0.5 ml X kg body wt-1 X min-1. Aerobic capacity varied with intensity of the occupational physical demand, except in groups with significant physical training programs. This first large US population study of aerobic capacity, using a direct treadmill procedure, demonstrates levels consistent with any previously reported population.

Maximal power outputs during the Wingate anaerobic test

The purpose of this study was to determine the resistance loads which elicit maximal values of power output (PO) during performance of the Wingate test (WT). Nineteen male subjects (mean age, 25.1 yrs; mean VO2 max, 3.52 l/min) performed multiple WTs in a random order at resistances ranging from 3.23 to 6.76 joules/pedal rev/kg BW. Tests were carried out on a Monark cycle ergometer modified to permit instantaneous application of resistance. Revolutions were determined by a computer interfaced frequency counter. The mean resistances eliciting the highest peak power (PP) and mean power (MP) outputs were 5.65 and 5.53 joules/pedal rev/kg BW, respectively (average of 5.59 joules/pedal rev/kg BW). Both PP and MP were significantly higher (15.5% and 13.0%, respectively) using a resistance load of 5.59 compared to the Wingate setting of 4.41 joules/pedal rev/kg BW. The test-retest reliability for PP and MP ranged between 0.91 and 0.93 at both resistance loads. Body weight and thigh volume did not significantly estimate the individual resistances eliciting maximal POs. The data suggest that resistance be assigned according to the subjects BW but consideration be given to increasing the resistance from that presently used in various laboratories.

Effects of acute cold exposure on submaximal endurance performance

The purposes of this study were to assess VO2max and submaximal endurance time to exhaustion (ET) during acute cold-air exposure. Eight male subjects (means age = 19.9 yr) were alternately exposed in groups of four to chamber temperatures of +20 degrees C and -20 degrees C for 30 h each. A week was allowed between exposures. Maximum oxygen uptake was measured using a mechanically-braked cycle ergometer, and ET was determined on the same ergometer using a 17-min/3-min exercise/rest schedule until the subject was unable to maintain pedal rate. Maximum oxygen uptake was not significantly different between conditions: 3.43 +/- 0.09 l X min-1 at +20 degrees C and 3.35 +/- 0.10 l X min-1 at -20 degrees C. During endurance exercise, intensities equaled 77.1 +/- 1.4% and 78.9 +/- 2.0% of VO2max at +20 degrees C and -20 degrees C, respectively. Heart rate and VO2 values obtained between 8 and 10 min of the endurance run were not significantly different (156 +/- 2 bpm and 2.63 +/- 0.08 l X min-1 at +20 degrees C and 158 +/- 3 bpm and 2.65 +/- 0.11 l X min-1 at -20 degrees C). Endurance time to exhaustion however, decreased 38% (P less than 0.05) from 111.9 +/- 22.8 min at +20 degrees C to 66.9 +/- 13.6 min at -20 degrees C. The data support the contention that aerobic capacity is not altered by cold exposure but suggest a marked decrease in submaximal endurance performance.

Effects of travel across time zones (jet-lag) on exercise capacity and performance

Eighty-one healthy male soldiers, aged 18-34, were studied for 5 d before and 5 d after an eastward deployment across six time zones to determine the effects of translocation on exercise capacity and performance. Fatigue, weakness, headache, sleepiness, irritability, and other commonly reported symptoms occurred in the majority of subjects. Most, but not all, of the symptoms were diminished or absent by the fifth day following the translocation. Cardiorespiratory function and perception of effort during both submaximal and maximal treadmill exercise were unaffected. Isometric strength of the upper torso, legs, and trunk extensor muscles also was not changed. Dynamic strength and endurance of elbow flexors declined significantly. Dynamic knee extensor strength and endurance scores exhibited a progressive decrement prior to translocation and were inconsistent suggesting that the stress of repetitive testing outweighed any jet-lag effects on performance capacity. Performance times for a 270 m sprint were increased for the first 4 d following translocation as were times for a 2.8 km run on the second and third days and for a 110 m lift and carry on the third day after deployment. Times for a 6.5 m rope climb did not change. These findings indicate that certain symptoms and physiological capacities are affected as a result of multiple time zone translocation. However, the specific mechanisms involved, the factors influencing the magnitude of any physiological alterations, and the ultimate impact of these capacity changes on actual physical performance remain to be clarified.

Response of age forty and over military personnel to an unsupervised, self-administered aerobic training program

The Army recently extended mandatory physical training and testing to include personnel 40 yrs of age and older. The purpose of this study was to describe the profile of aerobic fitness in a representative group from this age population and to evaluate the response of such a group to a self-administered, unsupervised training program. Maximal oxygen uptake (Vo2 max) and percent body fat (%BF) were assessed in 260 military personnel (40-53 yrs of age) before and after 6 mo of physical training consisting of a progressive walk/run mode of exercise. Before training the mean +/- S.D. for Vo2 max and %BF for all subjects was 38.1 +/- 6.2 ml/kg . min and 26.1 +/- 4.7%, respectively. Subjects were divided into three groups based upon their initial level of physical activity determined by interview as follows: inactive, moderately active and active. Upon retesting after 6 mo, 40% of the inactive group had not participated to any appreciable degree in the program and subjects of this group who did participate showed only a slight and insignificant increase (4.4%) in Vo2 max. The pretraining level of Vo2 max for the total population studied was similar to that reported in other studies on comparably aged subjects. However, changes with training were well below those seen with supervised group programs of 6 mo duration.

Evaluation of a maximal predictive cycle ergometer test of aerobic power

A maximal predictive cycle ergometer (CE) test for estimating maximal oxygen uptake (VO2 max) was evaluated in 15 male and 12 female subjects. The test consisted of pedalling a cycle ergometer (Monark) at 75 rev X min-1, beginning at an intensity of 37.5 watts and increasing by this amount each min until the subject could no longer maintain pedal rate. The highest work rate achieved was recorded as the endpoint of the test and used to construct regression equations to predict VO2 max. This was compared with two direct measures of VO2 max [an interrupted treadmill (TM) run and an interrupted CE procedure at 60 rev X min-1] and with the submaximal predictive test of Astrand-Rhyming. When compared to TM VO2 max, VO2 measured during the final 30 s of the maximal predictive CE test was 16.0% and 16.2% lower for males and females respectively; compared to VO2 max determined by the direct CE test, it was lower by 2.9% for males and 5.2% for females. Correlation coefficients for VO2 max predicted from the maximal predictive CE test and VO2 max measured directly by CE and TM were 0.89 and 0.87 for males and 0.88 and 0.83 for females (p less than 0.01), respectively. The VO2 max predicted from the Astrand-Rhyming test correlated significantly with VO2 max measured by CE and TM only in the male group. Test-retest reliability coefficients for intensity (watts) on the maximal predictive CE test were 0.95 and 0.81 for males and females respectively (p less than 0.01). The data suggest that this CE test gives a reliable and valid estimate of VO2 max.

Effects of training with eccentric muscle contractions on exercise performance, energy expenditure, and body temperature

To study the effects of exercise training with eccentric muscle contractions on body temperatures, energy cost, and performance capacity, six human subjects were tested before and after a 5-week training program of eccentric exercise. Exercise was performed as leg cycling on a motor-driven ergometer at power levels ranging 252-316 W. Training consisted of three sessions/week for 1 h/session. As a result of the training, VO2, fH, and mean skin temperature were lowered for each subject at the same absolute exercise intensities. Ability to continue exercise as indicated by endurance time improved with training. Before training, four subjects terminated exercise after 30 min because of localized leg exhaustion and one subject could not continue longer than 45 min. After training, all six subjects completed 45 min of the exercise test without difficulty. Esophageal and muscle temperatures evidenced no changes as a result of training. It was concluded that the inability of subjects to perform eccentric exercise in the untrained state was not related to muscle temperature.