The Evolution of Blood Flow Restricted Exercise

The use of blood flow restricted (BFR) exercise has become an accepted alternative approach to improve skeletal muscle mass and function and improve cardiovascular function in individuals that are not able to or do not wish to use traditional exercise protocols that rely on heavy loads and high training volumes. BFR exercise involves the reduction of blood flow to working skeletal muscle by applying a flexible cuff to the most proximal portions of a person\u27s arms or legs that results in decreased arterial flow to the exercising muscle and occluded venous return back to the central circulation. Safety concerns, especially related to the cardiovascular system, have not been consistently reported with a few exceptions; however, most researchers agree that BFR exercise can be a relatively safe technique for most people that are free from serious cardiovascular disease, as well as those with coronary artery disease, and also for people suffering from chronic conditions, such as multiple sclerosis, Parkinson\u27s, and osteoarthritis. Potential mechanisms to explain the benefits of BFR exercise are still mostly speculative and may require more invasive studies or the use of animal models to fully explore mechanisms of adaptation. The setting of absolute resistive pressures has evolved, from being based on an individual\u27s systolic blood pressure to a relative measure that is based on various percentages of the pressures needed to totally occlude blood flow in the exercising limb. However, since several other issues remain unresolved, such as the actual external loads used in combination with BFR, the type of cuff used to induce the blood flow restriction, and whether the restriction is continuous or intermittent, this paper will attempt to address these additional concerns

Effects of Acute and Sustained Pain Manipulations on Performance in a Visual‐Signal Detection Task of Attention in Rats

Preclinical ResearchPatients with pain often display cognitive impairment including deficits in attention. The visual‐signal detection task (VSDT) is a behavioral procedure for assessment of attention in rodents. Male Sprague Dawley rats were trained in a VSDT and tested with three different noxious stimuli: (i) intraperitoneal injection of lactic acid; (ii) intraplantar injection of formalin; and (iii) intraplantar injection of complete Freund's adjuvant (CFA). The muscarinic acetylcholine receptor antagonist, scopolamine was also tested as a positive control. Scopolamine (0.01–1.0 mg/kg) dose dependently reduced accuracy and increased response latencies during completed trials with higher scopolamine doses increasing omissions. Lactic acid (0.56–5.6% ip) also increased response latencies and omissions, although it failed to alter measures of response accuracy. Formalin produced a transient decrease in accuracy while also increasing both response latency and omissions. CFA failed to alter VSDT performance. Although VSDT effects were transient for formalin and absent for CFA, both treatments produced mechanical allodynia and paw edema for up to 7 days. These results support the potential for noxious stimuli to produce a pain‐related disruption of attention in rats. However, relatively strong noxious stimulation appears necessary to disrupt performance in this version of the VSDT. Drug Dev Res 76 : 194–203, 2015. © 2015 Wiley Periodicals, Inc.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/111955/1/ddr21255.pd

Comparing the Acute Effects of Intermittent and Continuous Whole-Body Vibration Exposure on Neuromuscular and Functional Measures in Sarcopenia and Nonsarcopenic Elderly Women

This investigation examined the acute effects of continuous whole-body vibration (CWBV) and intermittent whole-body vibration (IWBV) on neuromuscular and functional measures in women with sarcopenia and nonsarcopenic women. Continuous whole-body vibration was one 6-minute exposure, while IWBV consisted of six 60-second exposures to rest intervals (30 Hz, 2-4 mm amplitude). Factorial analyses revealed group × exposure × time interactions for jump height (JH; F = 10.8, P = .002), grip strength (GS; F = 15.5, P < .001), timed up and go test (F = 11.7, P = .002), and sit and reach test (S&R; F = 9.7, P = .004). Both JH and GS significantly improved post-WBV in women with sarcopenia (P < .001), with post-IWBV significantly greater (P < .001) than post-CWBV. Timed up and go test and S&R significantly improved post-IWBV in both the groups (P < .001) with post-IWBV significantly better than post-CWBV (P < .001). Bench press power at 20% one repetition maximum (1RM) revealed an exposure × time interaction (F = 4.6, P = .04) illuminating that IWBV significantly improved muscular power (P < .001). Bench press power at 40% 1RM revealed group × exposure (F = 6.4, P = .016) and exposure × time interactions (F = 5.8, P = .022). Individuals with sarcopenia significantly increased power output (P < .001) post-IWBV which was significantly greater than post-CWBV (P = .037). Bench press power at 60% 1RM revealed an exposure × time interaction (F = 8.6, P = .006), indicating that power was significantly improved post-IWBV (P = .027) and decreased post-CWBV. Berg Balance scale revealed a time main effect (F = 6.64, P = .015), and pain discomfort was significantly lower post-IWBV. These data indicate IWBV may provide a more efficacious exposure pattern in older women when compared to CWBV.The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article. Article processing charges funded in part by University of Oklahoma Libraries.YesTwo expert reviewers using single-blind process (reviewers' names and information is withheld from the authors). Established Ethics Policy with regards to who can review someone's work. The authors may nominate reviewers but the Editorial Board makes the final decision

Preclinical animal acute toxicity studies of new developed MRI contrast agent based on gadolinium

Acute toxicity test of new developed MRI contrast agent based on disodium salt of gadopentetic acid complex were carried out on Mus musculus and Sprague Dawley rats according to guidelines of preclinical studies [1]. Groups of six animals each were selected for experiment. Death and clinical symptoms of animals were recorded during 14 days. As a result the maximum tolerated dose (MTD) for female mice is 2.8 mМ/kg of body weight, male mice - 1.4 mМ/kg, female rats - 2.8 mМ/kg, male rats - 5.6 mМ/kg of body weight. No Observed Adverse Effect Dose (NOAEL) for female mice is 1.4 mМ/kg, male mice - 0.7 mМ/kg, male and female rats - 0.7 mМ/kg. According to experimental data new developed MRI contrast agent based on Gd-DTPA complex is low-toxic

Muscle Performance Changes with Age in Active Women

The purpose of this study was to examine age-related differences in muscle performance in women divided into young (YW, 20–39 years, n = 29) middle-aged (MAW, 40–59 years, n = 33), and older (OW, ≥60 years, n = 40) age groups. Methods: Hand grip strength, vertical jump performance, and knee extensor (KE) strength (0 deg/s, 60 deg/s, and 240 deg/s), speed of movement (SoM; at 1 Nm, 20%, 40%, and 60% isometric strength), and endurance (30-repetition test at 60 degs/s and 240 deg/s) were assessed. Computed tomography-acquired muscle cross-sectional area (mCSA) was measured and included to determine specific strength (KE strength/mCSA). Results: Hand grip strength was similar across groups, while jump performance declined with age (YW and MAW \u3e OW, p \u3c 0.001). KE strength declined significantly with age (all conditions p \u3c 0.01), while specific strength was similar across groups. SoM was significantly higher for YW and MAW compared to OW (both p \u3c 0.01). An age × velocity interaction revealed YW KE endurance was similar between conditions, whereas MAW and OW displayed significantly better endurance during the 60 deg/s condition. OW displayed impaired KE endurance at 240 deg/s (vs. YW and MAW, p \u3c 0.01) but improved at 60 deg/s (vs. YW, p \u3c 0.01). Dynamic torque decline increased with age (YW \u3c OW, p = 0.03) and was associated with intramuscular adipose tissue (r = 0.21, p = 0.04). Conclusions: Performance declines were most evident among OW, but few performance deficits had emerged in MAW. Interestingly, strength declines disappeared after normalizing to mCSA and endurance appears to be velocity-dependent

Monitoring External Training Loads and Neuromuscular Performance for Division I Basketball Players over the Preseason

Limited research has paralleled concomitant changes in external training load (eTL) and countermovement jump (CMJ) performance. Therefore, this investigation characterized eTL and CMJ performance changes across preseason training in Division 1 male collegiate basketball athletes, while examining the influence of position (Guard vs. Forward/Center) and scholarship status (Scholarship = S vs. Walk-on = WO). During 22 practices, eTL was monitored in 14 male athletes, with weekly CMJs performed to quantify neuromuscular performance (Jump Height [JH], Flight Time:Contraction Time [FT:CT], Reactive Strength Index Modified [RSIMod ]). PlayerLoad per minute was significantly higher during W1 and W2 (5.4 ± 1.3au and 5.3 ± 1.2au, respectively; p < 0.05) compared to subsequent weeks, but no additional differences in eTL parameters across time were observed. Scholarship athletes displayed greater PlayerLoad (S = 777.1 ± 35.6, WO = 530.1 ± 56.20; Inertial Movement Analysis (IMA) IMA_High (S = 70.9 ± 15.2, WO = 41.3 ± 15.2); IMA_Medium (S = 159.9 ± 30.7, WO = 92.7 ± 30.6); and IMA_Low (S = 700.6 ± 105.1, WO = 405 ± 105.0;) (p < 0.05), with no observed differences in eTL by position. Moderate decreases in FT:CT and RSIMod paralleled increased eTL. Significant increases in practice intensity (W1 and W2) did not impact CMJ performance, suggesting athletes could cope with the prescribed training loads. However, moderate perturbations in FT:CT and RSIMod paralleled the weeks with intensified training. Cumulatively, scholarship status appears to influence eTL while player position does not.The authors would like to thank Mr. Brady Brown and Mr. Keldon Peak for their assistance with this project. Additionally, the authors thank the Basketball Programs at the University of Oklahoma for their continued support of research directed at enhancing athlete performance, while also improving overall student-athlete welfare. Finally, the authors would also like to thank all of the student-athletes that graciously volunteered their time to enroll and participate in this study. The experiments comply with the current laws of the country in which they were performed. The authors have no conflict of interest to declare. Open Access fees paid for in whole or in part by the University of Oklahoma Libraries.Ye

Drug-cured experimental Trypanosoma cruzi infections confer long-lasting and cross-strain protection.

BACKGROUND: The long term and complex nature of Chagas disease in humans has restricted studies on vaccine feasibility. Animal models also have limitations due to technical difficulties in monitoring the extremely low parasite burden that is characteristic of chronic stage infections. Advances in imaging technology offer alternative approaches that circumvent these problems. Here, we describe the use of highly sensitive whole body in vivo imaging to assess the efficacy of recombinant viral vector vaccines and benznidazole-cured infections to protect mice from challenge with Trypanosoma cruzi. METHODOLOGY/PRINCIPAL FINDINGS: Mice were infected with T. cruzi strains modified to express a red-shifted luciferase reporter. Using bioluminescence imaging, we assessed the degree of immunity to re-infection conferred after benznidazole-cure. Those infected for 14 days or more, prior to the onset of benznidazole treatment, were highly protected from challenge with both homologous and heterologous strains. There was a >99% reduction in parasite burden, with parasites frequently undetectable after homologous challenge. This level of protection was considerably greater than that achieved with recombinant vaccines. It was also independent of the route of infection or size of the challenge inoculum, and was long-lasting, with no significant diminution in immunity after almost a year. When the primary infection was benznidazole-treated after 4 days (before completion of the first cycle of intracellular infection), the degree of protection was much reduced, an outcome associated with a minimal T. cruzi-specific IFN-?+ T cell response. CONCLUSIONS/SIGNIFICANCE: Our findings suggest that a protective Chagas disease vaccine must have the ability to eliminate parasites before they reach organs/tissues, such as the GI tract, where once established, they become largely refractory to the induced immune response

Stellar populations of Globular Clusters in the Elliptical galaxy NGC1407

We present high-quality, Keck spectroscopic data for a sample of 20 globular clusters (GCs) in the massive E0 galaxy NGC1407. A subset of twenty line-strength indices of the Lick/IDS system have been measured for both the GC system and the central integrated star-light of the galaxy. Ages, metallicities and [alpha/Fe] ratios have been derived using several different approaches. The majority GCs in NGC1407 studied are old, follow a tight metallicity sequence reaching values slightly above solar, and exhibit mean [alpha/Fe] ratios of ~ 0.3 dex. In addition, three GCs are formally derived to be young (~ 4 Gyr), but we argue that they are actually old GCs hosting blue horizontal branches. We report, for the first time, evidence for the existence of two chemically-distinct subpopulations of metal-rich (MR) GCs. We find some MR GCs exhibit significantly larger [Mg/Fe] and [C/Fe] ratios. Different star formation time-scales are proposed to explain the correlation between Mg and C abundances. We also find striking CN overabundances over the entire GC metallicity range. Interestingly, the behavior of C and N in metal-poor (MP) GCs clearly deviates from the one in MR GCs. In particular, for MR GCs, N increases dramatically while C essentially saturates. This may be interpreted as a consequence of the increasing importance of the CNO cycle with increasing metallicity.Comment: 53 pages, 11 figures, 5 tables. Accepted for publication in The Astronomical Journa