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Life sciences 2016 Jul 15
Authors:
Crabb EB, Franco RL, Caslin HL, Blanks AM, Bowen MK, Acevedo EO
Abstract
This study investigated the impact of acute physical and mental stress on serum concentrations of vascular cell adhesion molecule (VCAM)-1 and CX3CL1/fractalkine.
Male volunteers (n=20; 21.3±0.55years of age) completed a graded treadmill test to exhaustion and a 20-minute mental stress task (Stroop Color-Word Test, mental arithmetic) on separate, non-consecutive days. Heart rate (HR) was measured at baseline and throughout exercise and mental stress. Blood was collected at baseline (PRE), immediately following (POST) and 30min after (POST30) exercise and mental stress. Soluble VCAM-1 and fractalkine were quantified in participant serum via enzyme-linked immunosorbent assays.
Both treadmill exercise and the mental stress task significantly increased participant HR; although, exercise resulted in a substantially greater increase in participant HR compared to mental stress (197.82±11.99 vs. 38.67±3.10% [p<0.001]). VCAM-1 (815.74±139.55 vs. 738.67±131.59ng/mL [p=0.002]) and fractalkine (1.032±0.33 vs. 0.59±0.20ng/mL [p<0.001]) were significantly elevated in participant serum POST maximal exercise before returning to values similar to baseline at POST30. The acute mental stress task did not significantly alter serum VCAM-1 or fractalkine at any time point.
In conclusion, maximal aerobic exercise results in a significant elevation of the soluble adhesion molecules VCAM-1 and fractalkine in the serum of adult males that does not occur following laboratory-induced mental stress. The findings of the current investigation may suggest a novel protective role for acute aerobic exercise in vascular health via exercise-induced CAM proteolysis.
PMID:
27259811
[PubMed - as supplied by publisher]
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Life sciences 2016 Jan 15
Authors:
Blake Crabb E, Franco RL, Bowen MK, Huang CJ, Caslin HL, Acevedo EO
Abstract
This study investigated G-protein-coupled receptor kinase-2 (GRK2) density in peripheral blood mononuclear cells (PBMC) and its relationship to plasma pro-inflammatory cytokine concentrations following acute mental stress.
Apparently healthy males (n=20; 21.3±0.55years) participated in an acute mental stress task. Heart rate was measured at baseline and throughout mental stress. Plasma epinephrine (EPI), norepinephrine (NE), tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6) were assessed via enzyme-linked immunosorbent assays before, immediately following, and 30, 60 and 120min after the mental stress task. GRK2 density was measured by western blot technique at the same time points.
Acute mental stress elicited significant elevations in HR, and plasma EPI and NE. Additionally, GRK2 density increased significantly across time following the stress task. Post hoc analyses revealed that GRK2 density was significantly elevated at 30 and 60min following acute stress. A significant positive correlation was observed between GRK2 density and plasma EPI, while a significant negative correlation was revealed between GRK2 density and TNF-α across all time points.
Acute mental stress significantly increased GRK2 density in PBMCs of young adult males. Furthermore, although plasma IL-6 and TNF-α did not change following mental stress, it remains unknown whether a longer time period was needed to observe a pro-inflammatory state associated with the desensitization of β-adrenergic receptor activity. Our findings that GRK2 expression is promptly increased in PBMC following an acute stress task, may suggest a link between stress and intracellular inflammatory signaling.
PMID:
26706289
[PubMed - as supplied by publisher]
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Psychophysiology 2016 Feb
Authors:
Caslin HL, Franco RL, Crabb EB, Huang CJ, Bowen MK, Acevedo EO
Abstract
Obesity may contribute to cardiovascular disease (CVD) risk by eliciting chronic systemic inflammation and impairing the immune response to additional stressors. There has been little assessment of the effect of obesity on psychological stress, an independent risk factor for CVD. Therefore, it was of interest to examine interleukin-6, tumor necrosis factor-α, interleukin-1β (IL-1β), interleukin-1 receptor antagonist (IL-1Ra), and leptin following an acute mental stress task in nonobese and obese males. Twenty college-aged males (21.3 ± 0.56 years) volunteered to participate in a 20-min Stroop color-word and mirror-tracing task. Subjects were recruited for obese (body mass index: BMI > 30) and nonobese (BMI < 25) groups, and blood samples were collected for enzyme-linked immunosorbent assay analysis. The acute mental stress task elicited an increase in heart rate, catecholamines, and IL-1β in all subjects. Additionally, acute mental stress increased cortisol concentrations in the nonobese group. There was a significant reduction in leptin in obese subjects 30 min posttask compared with a decrease in nonobese subjects 120 min posttask. Interestingly, the relationship between the percent change in leptin and IL-1Ra at 120 min posttask in response to an acute mental stress task was only observed in nonobese individuals. This is the first study to suggest that adiposity in males may impact leptin and inflammatory signaling mechanisms following acute mental stress.
PMID:
26511907
[PubMed - as supplied by publisher]
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The Journal of pediatrics 2015 Aug
Authors:
Franco RL, Privett SH, Bowen MK, Acevedo EO, Arrowood JA, Wickham EP, Evans RK
Abstract
To evaluate differences in sympathetic activity, as assessed by an exercise recovery index (ERI; heart rate/oxygen consumption [VO2] plateau), between black and white obese female adolescents. An additional aim was to determine the association of ERI with insulin resistance (homeostasis model assessment of insulin resistance [HOMA-IR]), cardiovascular fitness per fat-free mass (VO2 per fat-free mass), systolic blood pressure (SBP), and percent body fat (%FAT) in both black and white obese adolescents.
Sixty-one females volunteered to participate in this study. HOMA-IR, SBP, and %FAT were assessed during resting conditions in black (n = 49, 13.7 ± 1.6 years, 38.1 ± 6.1 kg/m(2)) and white (n = 12, 13.3 ± 2.2 years, 34.3 ± 4.9 kg/m(2)) obese adolescents. An ERI was calculated during a 5-minute passive recovery period immediately following a graded treadmill exercise test to exhaustion.
The ERI was significantly greater in black compared with white obese adolescent females (29.8 ± 6.4 vs 24.1 ± 3.1 bpm·mLO2(-1)·min(-1), P = .004). Using multiple linear regression modeling, there was a significant independent association between ERI and VO2 per fat-free mass (r = -0.310, P = .027) and %FAT (r = 0.326, P = .020) in black obese adolescents after controlling for HOMA-IR and SBP.
These results suggest that black obese adolescent females have greater sympathetic activity, as assessed by an ERI, than white obese adolescent females. These findings support the need for weight management efforts aimed at both reducing %FAT and improving fitness in obese adolescents, specifically black females.
Registered with Clinicaltrials.gov: NCT00562293.
PMID:
26003997
[PubMed - as supplied by publisher]
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The Journal of pediatrics 2014 Dec
Authors:
Franco RL, Bowen MK, Arena R, Privett SH, Acevedo EO, Wickham EP, Evans RK
Abstract
To determine whether sex differences exist in the pulmonary oxygen uptake (VO2) uptake on-kinetic response to moderate exercise in obese adolescents. We also examined whether a relationship existed between the VO2 on-transient response to moderate intensity exercise, steady-state VO2, and peak VO2 between obese male and female adolescents.
Male (n = 12) and female (n = 28) adolescents completed a graded exercise test to exhaustion on a treadmill. Data from the initial 4 minutes of treadmill walking were used to determine the time constant.
The time constant was significantly different (P = .001) between obese male and female adolescents (15.17 ± 8.45 seconds vs 23.07 ± 8.91 seconds, respectively). No significant relationships were observed between the time constant and variables of interest in either sex.
Sex differences exist in VO2 uptake on-kinetics during moderate exercise in obese adolescents, indicating an enhanced potential for male subjects to deliver and/or use oxygen. It may be advantageous for female subjects to engage in a longer warm-up period before the initiation of an exercise regimen to prevent an early termination of the exercise session.
PMID:
25241180
[PubMed - as supplied by publisher]
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The American journal of sports medicine 2013 Dec
Authors:
Lynch TS, Saltzman MD, Ghodasra JH, Bilimoria KY, Bowen MK, Nuber GW
Abstract
Previous studies investigating acromioclavicular (AC) joint injuries in professional American football players have only been reported on quarterbacks during the 1980s and 1990s. These injuries have not been evaluated across all position players in the National Football League (NFL).
The purpose of this study was 4-fold: (1) to determine the incidence of AC joint injuries among all NFL position players; (2) to investigate whether player position, competition setting, type of play, and playing surface put an athlete at an increased risk for this type of injury; (3) to determine the incidence of operative and nonoperative management of these injuries; and (4) to compare the time missed for injuries treated nonoperatively to the time missed for injuries requiring surgical intervention.
Descriptive epidemiological study.
All documented injuries of the AC joint were retrospectively analyzed using the NFL Injury Surveillance System (NFLISS) over a 12-season period from 2000 through 2011. The data were analyzed by the anatomic location, player position, field conditions, type of play, requirement of surgical management, days missed per injury, and injury incidence.
Over 12 NFL seasons, there were a total of 2486 shoulder injuries, with 727 (29.2%) of these injuries involving the AC joint. The overall rate of AC joint injuries in these athletes was 26.1 injuries per 10,000 athlete exposures, with the majority of these injuries occurring during game activity on natural grass surfaces (incidence density ratio, 0.79) and most often during passing plays. These injuries occurred most frequently in defensive backs, wide receivers, and special teams players; however, the incidence of these injuries was greatest in quarterbacks (20.9 injuries per 100 players), followed by special teams players (20.7/100) and wide receivers (16.5/100). Overall, these athletes lost a mean of 9.8 days per injury, with quarterbacks losing the most time to injury (mean, 17.3 days). The majority of these injuries were low-grade AC joint sprains that were treated with nonoperative measures; only 13 (1.7%) required surgical management. Players who underwent surgical management lost a mean of 56.2 days.
Shoulder injuries, particularly those of the AC joint, occur frequently in the NFL. These injuries can result in time lost but rarely require operative management. Quarterbacks had the highest incidence of injury; however, this incidence is lower than in previous investigations that evaluated these injuries during the 1980s and 1990s.
PMID:
24057030
[PubMed - as supplied by publisher]
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The American journal of sports medicine 2013 Oct
Authors:
Robert HE, Bouguennec N, Vogeli D, Berton E, Bowen M
Abstract
Performing a single-bundle anterior cruciate ligament (ACL) reconstruction within the femoral footprint is important to obtain a functional graft and a stable knee.
There will be a significant difference in the ability of 3 ACL reconstruction techniques to reach and cover the native femoral footprint.
Controlled laboratory study.
The percentage of the ACL footprint covered by the femoral tunnel was compared after 3 different techniques to target the footprint: transtibial (TT), inside-out/anteromedial (IO), and outside-in/transfemoral (OI). Fourteen cadaveric knee specimens with a mean age of 67.5 years were used. For each knee, the TT technique utilized a 7.5-mm offset guide, the IO technique was performed through an accessory anteromedial portal, and the OI technique was carried out through the femur from the external wall of the lateral condyle. Entry points in the footprint were spotted with markers, and orientations (sagittal and frontal) of each drill guide were noted. The distal femurs were sawed and scanned, and 3-dimensional image reconstructions were analyzed. The virtual drilled area (reamer diameter, 8 mm) depending on the entry point and the sagittal/frontal orientation of the drill guide was calculated and reported for each of the 3 techniques. The distance from the tunnel center to the ACL center, percentage of the femoral tunnel within the ACL footprint, and percentage of the ACL footprint covered by the tunnel were calculated and statistically compared (analysis of variance and t test).
The average distance to the native femoral footprint center was 6.8 ± 2.68 mm for the TT, 2.84 ± 1.26 mm for the IO, and 2.56 ± 1.39 mm for the OI techniques. Average percentages of the femoral tunnel within the ACL footprint were 32%, 76%, and 78%, and average percentages of the ACL footprint covered by the tunnel were 35%, 54%, and 47%, for the TT, IO, and OI techniques, respectively. No significant difference was observed between the IO and OI techniques (P = .11). The TT approach gave less satisfactory coverage on all testing criteria.
The IO and OI techniques allowed for creation of a tunnel closest to the ACL femoral footprint center. Despite this fact and even if the average percentage of the drilled area included in the femoral footprint was close to 80% for these 2 techniques, the average percentage of the ACL footprint covered by the tunnels was <55% for all 3 techniques. Coverage of the ACL footprint depended on the entry point, orientation, and diameter of the drilling but also on the size of the footprint.
To improve the coverage of the native femoral footprint with a single-bundle graft, in addition to the entry point it may also be necessary to consider the orientation of the drilling to increase the dimensions of the area while respecting the anatomic constraints of the femoral bone and graft geometry.
PMID:
23940205
[PubMed - as supplied by publisher]
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Journal of pediatric orthopedics 2014 Jan
Authors:
Cassard X, Cavaignac E, Maubisson L, Bowen M
Abstract
The management of anterior cruciate ligament (ACL) tears in growing patients must balance activity modification with the risk of secondary (meniscal and cartilaginous) lesions, and surgical intervention, which could adversely affect skeletal growth. Many ACL reconstruction techniques have been developed or modified to decrease the risk of growth disturbance. We have not found any description of ACL reconstruction using a single hamstring, short graft implanted into intraepiphyseal, retroreamed sockets. Our hypothesis was that the technique that we used restored the knee stability and did not cause any growth disturbances.
We retrospectively studied 28 patients (20 boys, 8 girls) who presented with a unilateral ACL tear and open growth plates. We performed short graft ligament reconstruction with the semitendinosus folded into 4 strands around 2 polyethylene terephthalate tapes. The graft was implanted into sockets that were retroreamed in the femoral and tibial epiphysis and the tapes were fixed remotely by interference screws. After a minimum period of 2 years, we evaluated the comparative knee laxity, the radiographic limb morphology, the appearance of secondary lesions, and the functional outcomes using the Lysholm and Tegner scores. Comparative analyses were performed using the Student t test with subgroups depending on the type of fixation used.
The mean age of the patients was 13 years (range, 9 to 15 y). The mean follow-up was 2.8 years (range, 2 to 5 y). The mean difference in laxity at 134 N was 0.3 mm, as determined using a GNRB arthrometer. No patients reported meniscal symptoms or degenerative changes. We found no angular deformity or leg length inequality. Two patients suffered a recurrent ACL tear.
The preliminary results from this series are consistent with prior studies demonstrating that intraepiphyseal ACL reconstruction is a safe reliable alternative for the pediatric population.
Case series; level of evidence 4.
PMID:
23872797
[PubMed - as supplied by publisher]
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Orthopaedics & traumatology, surgery & research : OTSR 2012 Nov
Authors:
Cassard X, Bowen M, Collette M, Lanternier H, de Polignac T, Robert H
PMID:
23083805
[PubMed - as supplied by publisher]
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Journal of addictions nursing 2012 Oct
Authors:
Bowen MK, Taylor KP, Marcus-Aiyeku U, Krause-Parello CA
Abstract
Addiction rates in nurses are higher than in the general population. The relationship between stress, coping, and adaptation in nurses (N = 82) enrolled in a recovery and monitoring program in the state of New Jersey was examined. Social support, a variable tested as a mediator of this relationship, was also examined. Participants completed the Perceived Stress Scale, Multidimensional Scale of Perceived Social Support, and Psychological General Well-Being Index. Negative relationships were found between stress and social support and stress and well-being, and a positive relationship was found between social support and well-being (all ps < .05). The direct relationship between stress and well-being was decreased in the presence of social support. The findings of this research suggest that, to assist nurses, an increased awareness of stress and its injurious effects on overall well-being must be identified so proactive measures can be implemented to prevent potential untoward consequences. Ultimately, methods to strengthen social support and social networks will enhance the probability of sustained recovery, relapse prevention, and safe reentry into nursing practice. Implications for behavioral health providers and health care practitioners are discussed.
PMID:
24335732
[PubMed - as supplied by publisher]