Biodegradable Nerve Guide with Glial Cell Line-Derived Neurotrophic Factor Improves Recovery After Facial Nerve Injury in Rats

Background: Bioengineered nerve guides with glial cell line-derived neurotrophic factor (GDNF) support recovery after facial nerve injury by acting as regenerative scaffolds. Objective: To compare functional, electrophysiological, and histological outcomes after repair of rat facial nerve transection in control, empty nerve guide, and nerve guide with GDNF conditions. Methods: Rats underwent transection and primary repair of the buccal branch of the facial nerve and were divided into (1) transection and repair only, (2) transection and repair augmented with empty guide, (3) transection and repair augmented with GDNF-guide groups. Weekly measurements of the whisking movements were recorded. At 12 weeks, compound muscle action potentials (CMAPs) at the whisker pad were assessed, and samples were collected for histomorphometric analysis. Results: Rats in GDNF-guide group displayed the earliest peak in normalized whisking amplitude. CMAPs were significantly higher after GDNF-guide placement. Mean fiber surface area of the target muscle, axonal count of the injured branch, and the number of Schwann cells were highest with GDNF guides. Conclusion: The biodegradable nerve guide containing double-walled GDNF microspheres enhanced recovery after facial nerve transection and primary repair.

Intramuscular injection of skeletal muscle derived extracellular matrix mitigates denervation atrophy after sciatic nerve transection

Peripheral nerve injury and the associated muscle atrophy has an estimated annual healthcare burden of $150 billion dollars in the United States. When considering the total annual health-related spending of $3.5 trillion, these pathologies alone occupy about 4.3%. The prevalence of these ailments is rooted, at least in part, in the lack of specific preventative therapies that can be administered to muscle while it remains in the denervated state. To address this, skeletal muscle-derived ECM (skECM) was injected directly in denervated muscle with postoperative analysis performed at 20 weeks, including gait analysis, force production, cytokine quantification, and histological analysis. skECM was shown to be superior against non-injected muscle controls showing no difference in contraction force to uninjured muscle at 20 weeks. Cytokines IL-1β, IL-18, and IFNγ appeared to mediate regeneration with statistical regression implicating these cytokines as strong predictors of muscle contraction, showing significant linear correlation.

Physical Activity and Sedentary Behavior of Elderly Populations during Confinement: Results from the FRENCH COVID-19 ONAPS Survey

Introduction: A national confinement was imposed in France in March 2020 during 55 days to prevent the spread of the virus and protect vulnerable people such as older individuals. This study aimed to describe the movement behaviors, and their determinants, of elderly people (≥ 65 years) during the confinement.Methods: An online survey was conducted from April 1^st, 2020 to May 6^th, 2020 by the National Observatory for Physical Activity and Sedentary behaviors. This study compared the level of physical activity (PA), sitting and screen time before and during the confinement and identified the impact of initial PA, sedentary profiles of the participants and housing conditions.Results: 1,178 people were included in this study. Reaching PA recommendations before lock-down was associated with the change in PA level during lock-down (p < .001). Besides, geographic location was associated with the change in PA, sitting time and screen time during lock-down (respectively p = .03, p = .02, p = .02).Conclusion: This study confirm the negative impact of confinement on senior movement behaviors, whether or not they met with public health recommendations prior to the pandemic. The housing conditions of older people must be also taken into future public health policies.

The economic costs of planting, preserving, and managing the world's forests to mitigate climate change

Forests are critical for stabilizing our climate, but costs of mitigation over space, time, and stakeholder group remain uncertain. Using the Global Timber Model, we project mitigation potential and costs for four abatement activities across 16 regions for carbon price scenarios of $5-$100/tCO2. We project 0.6-6.0 GtCO2 yr-1 in global mitigation by 2055 at costs of 2-393 billion USD yr-1, with avoided tropical deforestation comprising 30-54% of total mitigation. Higher prices incentivize larger mitigation proportions via rotation and forest management activities in temperate and boreal biomes. Forest area increases 415-875 Mha relative to the baseline by 2055 at prices $35-$100/tCO2, with intensive plantations comprising <7% of this increase. Mitigation costs borne by private land managers comprise less than one-quarter of total costs. For forests to contribute ~10% of mitigation needed to limit global warming to 1.5 °C, carbon prices will need to reach $281/tCO2 in 2055.

The Effects of Concurrent Training Order on Satellite Cell-Related Markers, Body Composition, Muscular and Cardiorespiratory Fitness in Older Men with Sarcopenia

OBJECTIVES

Concurrent Training (CT) is described as a combination of resistance training (RT) and endurance training (ET) in a periodized program to maximize all aspects of physical performance. To date, effects of CT order on muscular and cardiorespiratory fitness adaptations are controversial. Owing to the age-related decrement in satellite cells (SC) which are critical for fiber repair, conservation, muscle hypertrophy as well as cardiorespiratory fitness, the present study examined the response of SC related markers to CT order in older sarcopenic men.

PARTICIPANTS

Thirty older men (age= 64.3 ± 3.5 years) were randomly assigned into one of 3 groups, ET followed by RT (E+R; n=10), RT followed by ET (R+E; n= 10) or a control (C; n=10).

INTERVENTION

The training protocol consisted of 3 exercise sessions per week for 8 weeks. Blood samples were obtained at baseline and 48 hours after the final training session.

RESULTS

Weight, skeletal muscle mass, lower and upper body power, maximal oxygen consumption (VO2max), Paired Box 7 (Pax7), and Myogenic factor 5 (Myf5) significantly increased, while were percent body fat significantly decreased following E+R and R+E compared to C. Importantly, the improvement in skeletal muscle mass, lower and upper body power, Myf5 and Pax7 in the E+R was significantly greater than the R+E group. Myogenin (Myog) and Paired Box 3 (Pax3) significantly increased (P < 0.01) in both training groups compared to no changes in C.

CONCLUSION

An 8-week CT intervention improves SC related markers, body composition and enhances power and VO2max in older sarcopenic participants, regardless of the order of RT and ET. However, performing ET before RT may be more effective at enhancing skeletal muscle mass, Myf5 and Pax7, in addition to both lower and upper body power. While both CT programs produced notable physiological and performance benefits, performing ET before RT during CT may provide the greatest therapeutic benefits for aging individuals.

Sitting to standing postural changes: Energy expenditure and a possible mechanism to alleviate sedentary behavior

Background and aims Sedentary lifestyles have recently been identified as potential mechanism for obesity and associated metabolic diseases linked to ill health. The aim of this study was to investigate the effects of standing and sitting-standing positional changes on energy cost and consequently interrupting sedentary sitting time while working. Methods A total of 26 healthy male volunteers performed normal typing and editing work for 100 min under three conditions. The conditions included sustained sitting, sustained standing, and sitting-standing alternation every 20 min using a sit-stand desk. Respiratory parameters measured included minute ventilation (VE), oxygen consumption (VO₂), and energy expenditure (EE). Measurements were recorded using a calibrated Cosmed K4b² portable gas analysis system. Results The mean value for VE was the highest in the standing position (VE = 13.33 ± 0.71), followed by sitting-standing alternation (VE = 12.04 ± 0.62). Both were significantly different from sitting (VE = 10.59 ± 0.69). The maximum VE and EE for standing (VE = 14.81 ± 0.43 and EE = 1.84 ± 0.10) and sitting-standing alternation (VE = 14.80 ± 0.40 and EE = 1.93 ± 0.08) were significantly higher than that of sitting (VE = 12.15 ± 0.42 and EE = 1.67 ± 0.07). No significant differences were observed in the mean VO₂ among the three conditions. However, the maximum VO₂ for both standing (VO₂ = 5.40 ± 0.20) and sitting-standing alternation (VO₂ = 5.14 ± 0.17) had shown to be significantly higher than sitting (VO₂ = 4.50 ± 0.18). There were no significant differences observed in the mean EE levels between sitting (EE = 1.43 ± 0.07) and sitting-standing alternation (EE = 1.55 ± 0.08). However, the mean EE while standing (EE = 1.62 ± 0.09) significantly increased compared to sitting. Conclusions The findings of this study indicate that sitting-standing alternations may be implemented as an effective intervention to interrupt prolonged sitting while working.

Utility of the hypertriglyceridemic waist phenotype in the cardiometabolic risk assessment of youth stratified by body mass index

BACKGROUND

It is unclear whether the hypertriglyceridemic waist phenotype (HTWP) can be used to identify those at most risk of cardiometabolic disorders.

OBJECTIVES

The utility of the HTWP as a useful predictor of cardiometabolic risk in youth stratified by body mass index was assessed.

METHODS

Three hundred and eighty-seven children (12-17.5 years) were used within this cross-sectional study. Participants were classified as normal weight or overweight/obese according to the International Obesity Task Force criteria. The HTWP phenotype was defined as having a waist circumference ≥90th percentile for age and gender with concomitant triglyceride concentrations ≥1.24 mmol L(-1) . Cardiometabolic risk profiles were compared using MANCOVA.

RESULTS

Normal weight participants with the HTWP had significantly higher levels of C-reactive protein 2.6 ± 0.4 vs. 1.6 ± 0.3 mg L(-1) (P < 0.05) and cardiometabolic risk scores (1.3 ± 0.3 vs. -0.7 ± 0.2 and 2.1 ± 0.4 vs. -0.5 ± 0.2; both P < 0.05) compared with those of a normal weight without the HTWP. Overweight/obese participants with the HTWP had significantly higher C-reactive protein levels (3.5 ± 0.6 vs. 2.6 ± 0.5; P < 0.05) as well as both cardiometabolic risk scores (1.6 ± 0.6 vs. 0.9 ± 0.2 and 2.2 ± 0.6 vs. 0.8 ± 0.2; both P < 0.001) when compared with overweight/obese participants without the HTWP.

CONCLUSIONS

The HTWP may serve as a simple and clinically useful approach to identify youth at increased cardiometabolic risk.

Sprint interval training (SIT) is an effective method to maintain cardiorespiratory fitness (CRF) and glucose homeostasis in Scottish adolescents

The present study examined the physiological impact of a school based sprint interval training (SIT) intervention in replacement of standard physical education (SPE) class on cardio-respiratory fitness (CRF) and glucose homeostasis during the semester following summer vacation. Participants (n=49) were randomly allocated to either intervention (SIT; n=26, aged 16.9 ± 0.3 yrs) or control group who underwent standard physical education (SPE; n=23, aged 16.8 ± 0.6 yrs). CRF (VO₂max) and glucose homeostasis were obtained prior-to and following 7 weeks of SIT exercise. Significant group x time interaction was observed for CRF (P < 0.01) with non-significant trends for fasting insulin (P= 0.08), and HOMA-IR (P=0.06). CRF decreased (P < 0.01) in SPE such that POST intervention CRF was significantly lower (P< 0.05) in SPE. Fasting plasma glucose (P < 0.01), insulin (P< 0.01) and HOMA-IR (P< 0.01) increased significantly amongst SPE. The main finding of the present study is that 7-weeks of SIT exercise is an effective method of maintaining (but not improving) CRF and fasting insulin homeostasis amongst school-going adolescents. SIT exercise demonstrates potential as a time efficient physiological adjunct to standard PE class in order to maintain CRF during the school term.

The Kinematics and Kinetics Analysis of the Lower Extremity in the Landing Phase of a Stop-jump Task

Large number of studies showed that landing with great impact forces may be a risk factor for knee injuries. The purpose of this study was to illustrate the different landing loads to lower extremity of both genders and examine the relationships among selected lower extremity kinematics and kinetics during the landing of a stop-jump task. A total of 35 male and 35 female healthy subjects were recruited in this study. Each subject executed five experiment actions. Lower extremity kinematics and kinetics were synchronously acquired. The comparison of lower extremity kinematics for different genders showed significant difference. The knee and hip maximum flexion angle, peak ground reaction force and peak knee extension moment have significantly decreased during the landing of the stop-jump task among the female subjects. The hip flexion angle at the initial foot contact phase showed significant correlation with peak ground reaction force during landing of the stop-jump task (r=-0.927, p<0.001). The knee flexion angle at the initial foot contact phase had significant correlation with peak ground reaction force and vertical ground reaction forces during landing of the stop-jump task (r=-0.908, p<0.001; r=0.812, P=0.002). A large hip and knee flexion angles at the initial foot contact with the ground did not necessarily reduce the impact force during landing, but active hip and knee flexion motions did. The hip and knee flexion motion of landing was an important technical factor that affects anterior cruciate ligament (ACL) loading during the landing of the stop-jump task.

Should an increase in cerebral neurochemicals following head kicks in full contact karate influence return to play?

Background:

Cerebral neurochemicals are markers of traumatic brain injury (TBI).

Objectives:

The aim of the study was to determine whether kicks to the head (KTH) in full contact karate significantly increased serum concentrations of protein S-100B, and neurone specific enolase (NSE). Kicks to the body (KTB) were also quantified to asses muscle tissue injury. Muscle damage was assessed by analysis of serum total creatine kinase (CK).

Methods:

Twenty-four full contact karate practitioners were observed and filmed during actual competition and divided into two main groups post event: (1) Kicks to the head and body group (KTH): n = 12; mean ± SD; age, 30.4 ± 6.7 years; height, 1.74 ± 0.1 m; weight, 79.1 ± 2.1 kg; and (2): Kicks to the body group (KTB): n = 12; mean ± SD; age, 28.2 ± 6.5 years; height, 1.75 ± 0.1 m; weight, 79.2 ± 1.7 kg. The KTH group received direct kicks to the head, while group KTB received kicks and punches to the body. Blood samples were taken before and immediately post-combat for analysis of serum S-100B, NSE, CK and cardiac troponin.

Results:

Significant increases in serum concentrations of S-100B (0.12 ± 0.17 vs. 0.37 ± 0.26, µg.L−1) and NSE (11.8 ± 4.1 vs. 20.2 ± 9.1 ng.mL−1) were encountered after combat in the KTH group and CK (123 ± 53 vs. 184 ± 103 U.L−1) in the KTB group (all P <0.05).

Conclusions:

Head kicks in full contact karate cause elevation of neurochemical markers associated with damaged brain tissue. The severity of injury is related to the early post-traumatic release of protein S-100B and NSE. The early kinetics and appearance post injury can reflect intracranial pathology, and suggest S-100B and NSE are extremely sensitive prognostic markers of TBI.

A consideration of the paradigm of exercise physiology

Exercise physiology, in terms of the history of biological sciences, is quite young and has a rather tumultuous history - as it spans physical education, health & medicine, sport science, and biology. This has led to the development of differing definitions, research approaches, practices and goals. This is easily seen in the presence of competing and non-universally adopted definitions of fitness. Such internal inconsistencies portray to the outside world a discipline experiencing the problems associated with a changing paradigm. Every science requires the presence of a paradigm that both describes and guides the evolution of thinking, experimentation, and the application of such. It is argued here that exercise physiology has been operating without benefit of a satisfactory and relevant paradigm. A further proposition is that the required disciplinary definitions derived from an articulated paradigm are also absent. A paradigmatic scheme based on biological dogma is presented along with proposed definitions.

Concentrations of salivary testosterone, cortisol, and immunoglobulin A after supra-maximal exercise in female adolescents

The aim of this study was to examine the effect of supra-maximal exercise on circulating concentrations of salivary testosterone, salivary cortisol, and salivary immunoglobulin A in female adolescents. Nineteen apparently healthy females aged 15-16 years participated in this study. All participants completed 668 s sprints, interspersed with 30 s recovery intervals on a cycle ergometer. Salivary testosterone, cortisol, and immunoglobulin A samples were taken before and 5 min after exercise. Experimental procedures continued over two mornings, at least 3 h after a light breakfast. Participants refrained from performing any strenuous physical activity for at least 24 h prior to the exercise test. None of the participants were engaged in a structured training programme. The group mean (± s) for peak power output was 562 ± 113.0 W. Female adolescents recruited for this study showed no changes in salivary testosterone, cortisol or immunoglobulin A following repeated bouts of supra-maximal cycling (P > 0.05). To date, there has been a paucity of information concerning adolescents' hormonal and mucosal immune function responses to supra-maximal exercise. Our data provide further guidance with regard to physical activities and sports prescription for female adolescents. Further research, on a larger sample of females, is required to elucidate the physiological significance of these findings.

Immunoendocrine responses over a three week international rugby union series

AIM

This study evaluated changes in immunoendocrine makers over an international series in professional rugby union players (N.=8).

METHODS

Venous bloods were taken on camp-entry, as well as before and after (0, 14 and 38 h) two games spaced over 21-days. Samples were analysed for changes in serum C-reactive protein (CRP), cortisol (C), testosterone (T), blood leukocytes, interleukin 6 (IL-6) and creatine kinase (CK).

RESULTS

Significant reductions in CK activity and CRP concentrations were evident on day 5 (pre-game 1) when compared to camp-entry (day 1); P<0.05. A large acute-phase response was observed following both games. Differences in the magnitude of this response appeared dependant on the number of collisions players experienced during play. Compared to camp-entry, sharp increases in C (40%) and decreases (37%) in T were evident after both games; P<0.05. A gradual increase in T/C ratio was observed throughout the tournament; values 35% and 45% higher on days 19 and 21 than those observed at camp-entry (P<0.05).

CONCLUSION

Current data suggests that improved physiological recovery can be achieved during an international rugby union series. Monitoring of previous club activity is essential to ensure optimal player readiness prior to participation in international rugby union games.

Secular trends in established and novel cardiovascular risk factors in Welsh 12-13 year olds: a comparison between 2002 and 2007

BACKGROUND

This study examines CVD risk factors trends in Welsh adolescents between 2002 and 2007.

PARTICIPANTS AND METHODS

CVD risk factor data was examined from two cross-sectional studies. The first study (73 participants; aged 12.9 ± 0.3 years) was completed in 2002. The second study (90 participants; aged 12.9 ± 0.4 years) was conducted in 2007. Measurements included body mass index (BMI), waist circumference (WC), total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, triglyceride, fibrinogen (Fg) and high-sensitivity C-reactive protein (hs-CRP).

RESULTS

In boys, mean BMI and WC were lower in 2007, although not significantly (p ≥ 0.05). In 2007, there were improvements in mean lipid, Fg and hs-CRP concentrations in both sexes (p < 0.05). In 2002, 42.8% of boys and 34.2% of girls were overweight or obese; in 2007, this was 23.7% and 28.9% for boys and girls, respectively. More adolescents in 2002 exceeded the recommended levels for lipids, Fg and hs-CRP.

CONCLUSION

This is the only study to examine CVD risk factor trends in Welsh adolescents. Although overweight continues to be widespread in 12-13 year olds, this study did not identify significant mean changes in overweight and obesity between 2002 and 2007. Overall, the data presented a positive trend in lipid profile and inflammatory factors.

Further mechanical considerations between polar and SRM mobile ergometer systems during laboratory-based high-intensity, intermittent cycling activity

The purpose of this article is to outline mechanical issues related to the use of the Polar S710 heart monitor with Power Unit when compared with the SRM Powercrank system. There are issues outlined in this article that refer to the suitability of the Polar S710 for the quantification of performance during downhill cycling that relate to chain vibration, chain tension, and time interval sampling rates.

Steroid and prescription medicine abuse in the health and fitness community: A regional study

BACKGROUND

The purpose of this study was to identify the prevalence of abuse of certain prescription medicines (POM) amongst health club attendees. The non-therapeutic use of such medicines has previously been considered to be restricted to the professional athlete.

METHODS

In the summer of 2005, health club users in the South Wales area were given questionnaires and asked to return them in a stamped, addressed envelope. Anonymity of the respondents was assured.

RESULTS

From the distribution of 210 questionnaires, the response rate was 69.5% (146 questionnaires). The mean age of the sample was 33.6+/-6.7 years (range 15-72 years). Anabolic-androgenic steroid (AAS) use is prominent amongst recreational gym users in this regional sample, with 70% (102 individuals) reporting AAS use, 65.8% (96 individuals) of whom were currently still using. Some 7% of respondents (10 individuals) were female and they also reported taking medication. This research demonstrated an enormous increase in the use of growth hormone (24%), insulin (14%), and tamoxifen (22%), with smaller increases in other drugs.

CONCLUSION

Drug users were from all levels of society and reported various physiological and psychological side effects from their use. The present study indicated that the most used medicine/drug from less than reputable sources was still AAS but that, as a consequence of the internet revolution, they were being caught up by the more expensive designer drugs, particularly growth hormone. Physicians and medical personnel must become aware that the use of AAS and other prescription medicines is on the increase and appears to be predominantly used for cosmetic reasons.

Changes in Blood Markers of Serotoninergic Activity Following High Intensity Cycle Ergometer Exercise

The purpose of this study was to measure concentrations of adrenaline (A), noradrenaline (NE), free tryptophan (f-Trp), prolactin (PRL), nonesterified fatty acids (NEFA), and blood lactate following 30 s of high-intensity cycle ergometer exercise. Adrenaline (A) and NE concentrations increased immediately postexercise (P < 0.05) and returned to levels observed at baseline 24 h later. Plasma f-Trp concentration decreased by 23.5% immediately following exercise (P < 0.05). There were no changes observed in serum concentrations of PRL. Plasma NEFA concentrations decreased immediately following exercise by 46% (P < 0.05) and returned to baseline values 24 h later. Whole blood lactate concentrations increased immediately post exercise (P < 0.05), and were higher than those measured 24 h later (P < 0.05). These findings indicate that blood markers of serotoninergic activity were unaltered by a single 30 s bout of maximal cycling.

Homocysteine induced cardiovascular events: a consequence of long term anabolic-androgenic steroid (AAS) abuse

OBJECTIVES

The long term effects (>20 years) of anabolic-androgenic steroid (AAS) use on plasma concentrations of homocysteine (HCY), folate, testosterone, sex hormone binding globulin (SHBG), free androgen index, urea, creatinine, haematocrit (HCT), vitamin B12, and urinary testosterone/epitestosterone (T/E) ratio, were examined in a cohort of self-prescribing bodybuilders.

METHODS

Subjects (n = 40) were divided into four distinct groups: (1) AAS users still using AAS (SU; n = 10); (2) AAS users abstinent from AAS administration for 3 months (SA; n = 10); (3) non-drug using bodybuilding controls (BC; n = 10); and (4) sedentary male controls (SC; n = 10).

RESULTS

HCY levels were significantly higher in SU compared with BC and SC (p<0.01), and with SA (p<0.05). Fat free mass was significantly higher in both groups of AAS users (p<0.01). Daily energy intake (kJ) and daily protein intake (g/day) were significantly higher in SU and SA (p<0.05) compared with BC and SC, but were unlikely to be responsible for the observed HCY increases. HCT concentrations were significantly higher in the SU group (p<0.01). A significant linear inverse relationship was observed in the SU group between SHBG and HCY (r = -0.828, p<0.01), indicating a possible influence of the sex hormones in determining HCY levels.

CONCLUSIONS

With mounting evidence linking AAS to adverse effects on some clotting factors, the significantly higher levels of HCY and HCT observed in the SU group suggest long term AAS users have increased risk of future thromboembolic events.

Development of a healthy biscuit: an alternative approach to biscuit manufacture

OBJECTIVE

Obesity (BMI >30) and related health problems, including coronary heart disease (CHD), is without question a public health concern. The purpose of this study was to modify a traditional biscuit by the addition of vitamin B6, vitamin B12, Folic Acid, Vitamin C and Prebiotic fibre, while reducing salt and sugar.

DESIGN

Development and commercial manufacture of the functional biscuit was carried out in collaboration with a well known and respected biscuit manufacturer of International reputation. The raw materials traditionally referred to as essential in biscuit manufacture, i.e. sugar and fat, were targeted for removal or reduction. In addition, salt was completely removed from the recipe.

PARTICIPANTS

University students of both sexes (n = 25) agreed to act as subjects for the study. Ethical approval for the study was granted by the University ethics committee. The test was conducted as a single blind crossover design, and the modified and traditional biscuits were presented to the subjects under the same experimental conditions in a random fashion.

RESULTS

No difference was observed between the original and the modified product for taste and consistency (P > 0.05). The modified biscuit was acceptable to the consumer in terms of eating quality, flavour and colour. Commercial acceptability was therefore established.

CONCLUSION

This study has confirmed that traditional high-fat and high-sugar biscuits which are not associated with healthy diets by most consumers can be modified to produce a healthy alternative that can be manufactured under strict commercial conditions.

Catecholamine responses to high intensity cycle ergometer exercise: Body mass or body composition?

The purpose of this study was to compare the sympathoadrenergic and metabolic responses following 30 s of maximal high intensity cycle ergometry exercise when cradle resistive forces were derived from total-body mass (TBM) or fat-free mass (FFM). Increases in peak power output (PPO) and pedal velocity were recorded when resistive forces reflected FFM (953 +/- 114 W vs 1020 +/- 134 W; 134 +/- 8 rpm vs 141 +/- 7 rpm ; P < 0.05). No differences were observed between mean power output (MPO), fatigue index (FI%), work done (WD) or heart rate (HR) when the TBM and FFM protocols were compared. There were no differences between the TBM and FFM protocols for adrenaline (A), noradrenaline (NA) or blood lactate concentrations ([La-]B) recorded at rest, immediately post or 24 h post exercise. However, increases in blood concentrations of A and NA (P < 0.05) were recorded for both the TBM and FFM protocol immediately post exercise. Significant correlations (P < 0.05) were recorded between PPOs, immediate post- exercise NA and [La-]B for both the TBM and FFM protocols. [La-]B levels were also significantly elevated (P < 0.01) immediately post exercise for both the TBM and FFM protocols. The results from this study suggest that greater peak power outputs are obtainable with no subsequent differences in neurophysiological or metabolic stress as determined by plasma A, NA and [La-]B concentrations when resistive forces reflect FFM and not TBM during loading procedures. The findings also indicate that immediate post exercise concentrations return to resting levels 24 h post exercise.

High intensity exercise assessment: relationships between laboratory and field measures of performance

The purpose of this study was to examine the relationship between high intensity cycle ergometry when resistive forces were optimised and field tests of high intensity performance in an elite sprint trained group (n = 12). Body mass, stature and age of the group were determined prior to testing (66.3 +/- 9.8kg, 177 +/- 7.6cm and 17 +/- 0.74 yrs respectively). Field tests of high intensity performance examined included sprinting. maximal shuttle running and jumping ability (vertical and horizontal). Significant correlations existed between all field tests (P < 0.01). Only moderate correlations were observed for values generated on the cycle ergometer and performance tests (P > 0.05). The results of the present study suggest that the optimised cycle ergometer test and the performance tests are unrelated when evaluated statistically. These findings also suggest that the sprinting and jumping tests examined are highly related and may be substituted for each other as possible predictors of high intensity ability.

Replication-independent assembly of an insect virus (Tetraviridae) in plant cells

Infectious virions of the insect RNA virus Helicoverpa armigera stunt virus (HaSV; Omegatetravirus, Tetraviridae) were assembled in cultured plant protoplasts of Nicotiana plumbaginifolia in the absence of detectable replication. Assembly of the virus, which has not been grown in cell culture, required cotransfection of a DNA plasmid expressing the HaSV capsid gene in combination with either genomic RNA or with DNA plasmids carrying the complete cDNAs to the two HaSV genomic RNAs. Each cDNA was placed under the control of the cauliflower mosaic virus 35S promoter and followed by a cis-acting ribozyme so that the resultant transcripts corresponded precisely to the two genomic RNAs. Protoplast assembly of infectious particles was confirmed by EM and bioassay of host insect larvae, which became diseased and produced virus particles confirmed as HaSV. Variant transcripts carrying nonviral sequences at either or both termini of the RNAs showed no infectivity, except for RNA2 carrying only a 3' terminal extension. No replication of HaSV in protoplasts was detected in pulse-labeling and blotting experiments. Insects showed less severe disease symptoms when fed protoplasts transfected with only the RNA1 and coat protein plasmids. The symptomatic larvae contained only RNA1 and failed to yield infectious progeny virus, suggesting that RNA1 is capable of self-replication. This novel plasmid-based system confirms that the reported sequence of HaSV represents an infective genome and establishes a procedure for the reverse genetics of a tetravirus.

The relationship between total-body mass, fat-free mass and cycle ergometry power components during 20 seconds of maximal exercise

The purpose of this study was to compare the maximal exercise performance of 10 men during friction braked cycle ergometry of 20 s duration when resistive forces reflected total body mass (TBM) or fat free mass (FFM). Fat mass was calculated from the sum of skinfold thicknesses. Increases (P < 0.05) in peak power output (PPO) were found between TBM and FFM (1,015+/-165 W TBM vs 1,099+/-172 W FFM). Decreases (P < 0.05) were observed for the time taken to reach PPO (3.8+/-1.4 s TBM vs 2.9+/-1 s FFM). Pedal velocity increased (P < 0.05) during the FFM protocol (129.4+/-8.2 rpm TBM vs 136.3+/-8 rpm FFM). Rating of perceived exertion (RPE) was also (P < 0.05) greater for FFM (18.4+/-1.6 TBM vs 19.8+/-0.4 FFM). No changes were found for Mean Power Output (MPO), fatigue index (FI) or Work Done (WD) between trials. These findings suggest that high intensity resistive force loading protocols may need to be reconsidered. Results from this study indicate that the active tissue component of body composition needs consideration in resistive force selection when ascertaining maximal cycle ergometer power profiles.

Power output of legs during high intensity cycle ergometry: influence of hand grip

Indices of mechanical power output were obtained from twelve subjects during high intensity leg cycle ergometry tests (20 second duration; 75 grams per kilogram total body mass) using two protocols: one with a standard handle-bar grip (with-grip), and one with supinated wrists (without-grip). Peak mechanical power, mean mechanical power, fatigue index and total mechanical work values were calculated for each subject during each test, and the sample mean differences associated with the two protocols were compared using paired Student t-tests. The with-grip protocol yielded significantly greater peak mechanical power output and greater fatigue index than the without-grip protocol (886 +/- 124W and 815 +/- 151W, respectively; and 35 +/- 10% and 25 +/- 8%, respectively; p<0.01). The electrical activity of the anterior forearm musculature was measured in the twelfth subject during the performance of each of the test protocols. While peak mechanical power output was greater during the with-grip protocol, than during the without-grip protocol, the electromyographs showed much greater forearm muscle activity during the with-grip protocol. Thus the protocol which allowed for the greatest measure of peak leg power output was also associated with considerable arm muscle activity. These findings should be considered when biochemical and physiological measurements are obtained from arm blood samples.

Lungworm infection in a sheep flock in Maryland

First-stage larvae of Protostrongylus rufescens were detected in the feces of a ram with diarrhea, anorexia, weight loss, and mucopurulent nasal discharge. Subsequently, a survey was initiated in the experimental sheep flocks maintained at the Agricultural Research Service's Helminthic Diseases Laboratory in Beltsville, Md to determine the extent and effect of infection with the parasite. Five of 31 ewes and 4 of 16 rams were found to be infected with the lungworm. Clinical signs of infection, which ranged from mild to severe, included diarrhea, weight loss, and respiratory distress. Natural transmission of the parasite to parasite-naive lambs grazing on pasture occurred during the course of this study. Three lambs born to infected ewes during this study were not infected, suggesting that there is no vertical transmission. Additionally, cattle grazing the same pastures as infected sheep were not infected with the parasite. Results of this study indicated that Protostrongylus rufescens can cause serious disease in domestic sheep in the United States and should be considered as a differential diagnosis in sheep with nonspecific respiratory tract signs.

Preparation of triazolo[1,5-c]pyrimidines as potential antiasthma agents

With the use of the human basophil histamine release assay, 5-aryl-2-amino[1,2,4]triazolo[1,5-c]pyrimidines were found to be active as mediator release inhibitors. These compounds were prepared by reacting arylamidines with sodium ethyl formylacetate or with ethyl propiolate to give pyrimidinones. Treatment with phosphorus oxychloride gave a chloropyrimidine, which was converted to a hydrazinopyrimidine with hydrazine. Cyclization, using cyanogen bromide, gave the triazolo[1,5-c]pyrimidines, after a Dimroth rearrangement. Following a structure-activity evaluation, the 5-[3-(trifluoromethyl)phenyl]-2-amino (8-10), 5-(3-bromophenyl)-2-amino (8-13), 5-[3-(difluoromethoxy)-phenyl]-2-amino (8-11), and 5-(4-pyridinyl)-2-amino (6-7) compounds were found to have the best activity. They were chosen for further pharmacological and toxicological study.

Effects of lipoxygenase inhibitors in a model of lens-induced uveitis in dogs

Uveitis was induced in dogs by intracameral injection of canine lens protein. The lipoxygenase inhibitors phenidone and norhydroguaiaretic acid, and dimethyl sulfoxide decreased fibrin production at 0.5 and 1 hour after induction of uveitis. Phenidone and norhydroguaiaretic acid also inhibited the initial increase in intraocular pressure early in the course of inflammation. Leukotriene B4 in the aqueous was measured by use of radioimmunoassay at 1 hour after inflammation. In control dogs, 230 to 1,700 pg of leukotriene B4/ml was measured; in dogs treated with phenidone, leukotriene B4 was not measured.

Variations in bacitracin susceptibility observed in Staphylococcus and Micrococcus species

Bacitracin susceptibility was evaluated as a laboratory method to differentiate staphylococci from micrococci. A total of 317 staphylococcal isolates and 108 micrococcal isolates were each tested for susceptibility to bacitracin by a disk-diffusion method using disks of three different potencies (0.04, 2.0, and 10.0 U) and a broth dilution method to obtain MICs. When a growth inhibition zone diameter breakpoint of greater than 10 mm was used to establish susceptibility with a 0.04-U disk, all micrococci were bacitracin susceptible and 94.6% of the staphylococci were resistant. Testing with disks of higher potency did not improve the specificity of the disk-diffusion method.

Evaluation of various rapid agglutination methods for the identification of Staphylococcus aureus

A latex agglutination test (SeroSTAT Staph; Scott Laboratories, Fiskeville, R.I.) and two hemagglutination tests (Staphyloslide; BBL Microbiology Systems, Cockeysville, Md.; and Hemastaph; Remel, Lenexa, Kans.) were compared with the slide coagulase (SC) and tube coagulase (TC) tests at room temperature (22 to 25 degrees C) and at 37 degrees C for the rapid identification of Staphylococcus aureus. A total of 380 clinical strains of staphylococci were tested. The TC test performed at room temperature yielded the largest number of TC-positive results (n = 239), and based on this observation 239 organisms were classified as S. aureus and 141 were classified as non-S. aureus. The SC, TC (37 degrees C), SeroSTAT Staph, Staphyloslide, and Hemastaph tests correctly identified 210 (87.9%), 221 (92.5%), 238 (99.6%), 239 (100%), and 236 (98.7%) of the S. aureus isolates, respectively. Of the S. aureus isolates that were TC positive at room temperature 68% required 24 h of incubation before coagulase production was detected. There was one false-negative SeroSTAT Staph result and one false-negative Hemastaph result. The Staphyloslide test yielded two noninterpretable results (both organisms were later confirmed as non-S. aureus), whereas there were six noninterpretable results recorded with the Hemastaph test (four organisms were classified as non-S. aureus, and two were classified as S. aureus). The SeroSTAT Staph, Staphyloslide, and Hemastaph tests were all more sensitive than the conventional SC and TC (37 degrees C) tests and were considerably more rapid than the TC test at either temperature.

Postpartum atony of the small and large intestine in a Holstein cow: a case of pseudo-obstruction

A four-year-old Holstein, 23 days postpartum, was presented with abdominal distention. Gas filled viscera were detected in the right paralumbar fossa and pelvic canal. Surgery revealed cecal and colonic distention and generalized intestinal atony. There was no other evidence of gross pathology. The condition deteriorated during five post-operative days. Gross postmortem findings were not remarkable; histopathology revealed ganglionitis of the cranial mesenteric ganglion and myenteric plexus. A brief review of relevant literature for a differential diagnosis and an etiology is discussed.

Comparison of various methods for differentiation of staphylococci and micrococci

A modified oxidase test (Remel, Lenexa, Kans.) and susceptibility to furazolidone and lysostaphin (Remel) were evaluated in conjunction with the Staph-Ident strip (Analytab Products, Plainview, N.Y.) to accurately differentiate between staphylococci and micrococci. A total of 414 clinical isolates of catalase-positive, gram-positive cocci were each tested with the Staph-Ident strip and by glucose fermentation, acid production from glycerol, susceptibility to furazolidone and lysostaphin, and the oxidase test. Based on the reference methods of glucose fermentation and acid production from glycerol, 396 (95.6%) of the organisms were classified as Staphylococcus species and 18 (4.4%) were classified as Micrococcus species. Of the staphylococci, 99% were oxidase negative and susceptible to furazolidone; 82% were susceptible to lysostaphin. All of the micrococci were oxidase-positive and resistant to furazolidone and lysostaphin. Of the staphylococci, 99% were identified to species by the Staph-Ident strip. However, six (33%) of the micrococci were incorrectly identified as Staphylococcus species (three each of Staphylococcus hominis and Staphylococcus saprophyticus). Because of the demonstrated sensitivity and specificity of the oxidase and furazolidone susceptibility tests, it is suggested that either of these methods be used in the clinical laboratory to accurately differentiate between staphylococci and micrococci. It is also suggested that when working with the Staph-Ident strip, additional testing such as furazolidone susceptibility or oxidase activity should be performed to provide increased accuracy in the differentiation and characterization of members of the family Micrococcaceae.

Particle size distribution analysis as a rapid method to detect significant bacteriuria

Particle size distribution analysis (PSDA) was evaluated as a rapid screening method for detecting significant bacteriuria by linking a C1000 Channelyzer to a Coulter Counter. Colony counts and PSDA screening results were compared for 800 urine specimens. The PSDA method proved to be 92% specific, but only 64% sensitive, for detecting at least 10(5) colony forming units (CFU)/ml. By performing serial dilution colony counts on 109 culture-positive specimens (greater than or equal to 10(5) CFU/ml), it was determined that the low level of sensitivity (64%) was due to culture-positive specimens that had between 10(5) and less than 10(7) CFU/ml. The sensitivity of the PSDA method increased to 90% and 100% when culture-positive specimens had 10(7) or more and 10(8) or more CFU/ml, respectively. The low level of sensitivity demonstrated in this investigation makes the introduction of this method into clinical usage unacceptable at this time.

In vitro antagonism by erythromycin of the bactericidal action of antimicrobial agents against common respiratory pathogens

Ten strains each of Staphylococcus aureus, Haemophilus influenzae, Enterobacter spp., Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis, Pseudomonas aeruginosa, and Streptococcus pneumoniae were tested in vitro against erythromycin combined with ampicillin, cefamandole, or gentamicin. Antagonism by erythromycin occurred with 47% of the combinations involving strains of S. aureus and to a lesser degree with H. influenzae. Synergy occurred most commonly with H. influenzae (27%). The high frequency of antagonism and synergy with these organisms was associated with a broad range of bacteriostatic action by erythromycin against these same bacteria. The implications for the treatment of pneumonia are discussed.

The eyeblink as a time-locked response: Implications for serial and second-order conditioning

A series of experiments were conducted to determine what factors control responding to the first element of a two-element serial compound in rabbit eyelid conditioning. An examination of response topography indicated that the eye-blink CR is rigidly timed to occur when the US is expected. This response-system characteristic prevents the occurrence of a CR during the first element of a serial compound or during the second-order CS in second-order conditioning. The comparison of a serial gap procedure with conventional serial and trace conditioning procedures suggested that the associative strength of the first element of a serial CS is not strongly influenced by either a second-order conditioning process or by the variable-reinforcement principle.

The eye blink as a time-locked response: implications for serial and second-order conditioning

A series of experiments were conducted to determine what factors control responding to the first element of a two-element serial compound in rabbit eyelid conditioning. An examination of response topography indicated that the eye-blink CR is rigidly timed to occur when the US is expected. This response-system characteristic prevents the occurrence of a CR during the first element of a serial compound or during the second-order CS in second-order conditioning. The comparison of a serial gap procedure with conventional serial and trace conditioning procedures suggested that the associative strength of the first element of a serial CS is not strongly influenced by either a second-order conditioning process or by the variable-reinforcement principle.