Analysis of platelet-rich plasma extraction variations in platelet and blood components between 4 common commercial kits

Background: Platelet-rich plasma (PRP) has been extensively used as a treatment in tissue healing in tendinopathy, muscle injury, and osteoarthritis. However, there is variation in methods of extraction, and this produces different types of PRP. Purpose: To determine the composition of PRP obtained from 4 commercial separation kits, which would allow assessment of current classification systems used in cross-study comparisons. Study Design: Controlled laboratory study. Methods: Three normal adults each donated 181 mL of whole blood, some of which served as a control and the remainder of which was processed through 4 PRP separation kits: GPS III (Biomet Biologics), Smart-Prep2 (Harvest Terumo), Magellan (Arteriocyte Medical Systems), and ACP (Device Technologies). The resultant PRP was tested for platelet count, red blood cell count, and white blood cell count, including differential in a commercial pathology laboratory. Glucose and pH measurements were obtained from a blood gas autoanalyzer machine. Results: Three kits taking samples from the “buffy coat layer” were found to have greater concentrations of platelets (3-6 times baseline), while 1 kit taking samples from plasma was found to have platelet concentrations of only 1.5 times baseline. The same 3 kits produced an increased concentration of white blood cells (3-6 times baseline); these consisted of neutrophils, leukocytes, and monocytes. This represents high concentrations of platelets and white blood cells. A small drop in pH was thought to relate to the citrate used in the sample preparation. Interestingly, an unexpected increase in glucose concentrations, with 3 to 6 times greater than baseline levels, was found in all samples. Conclusion:This study reveals the variation of blood components, including platelets, red blood cells, leukocytes, pH, and glucose in PRP extractions. The high concentrations of cells are important, as the white blood cell count in PRP samples has frequently been ignored, being considered insignificant. The lack of standardization of PRP preparation for clinical use has contributed at least in part to the varying clinical efficacy in PRP use. Clinical Relevance: The variation of platelet and other blood component concentrations between commercial PRP kits may affect clinical treatment outcomes. There is a need for standardization of PRP for clinical use

Validation of Maximal Heart Rate Prediction Equations based on Sex and Physical Activity Status

International Journal of Exercise Science 8(4): 318-330, 2015. The purpose of the study was to determine if measured maximal heart rate (HRmax) was affected by sex or aerobic training status, and to determine the accuracy of three common clinical age-prediction maximal heart rate regression equations used to predict HRmax: HRmax = 220 – age, HRmax = 226 – age, and HRmax = 208 – (0.7 ∙ age). Fifty-two participants in total, 30 of which were in the active group (15 M, 15 F) and 22 subjects in the sedentary group (9 M, 13 F), within the age range of 18-25 years and with a normal BMI (18.5-24.9 kg∙m-2) underwent a Bruce maximal treadmill exercise protocol. The effect of sex and training status on HRmax was analyzed through a two-way ANOVA, and the effect of sex, aerobic training status, and regression equation on accuracy of the HRmax prediction was assessed with a three-way ANOVA (α=0.05). Overall, males had a higher HRmax than females (198.3 v. 190.4 beats • min-1 , p\u3c.001) and sedentary individuals had higher measured HRmax than active individuals (197.3 v. 191.4 beats • min-1, p=.002). Furthermore, HRmax = 208 – (0.7 ∙ age)(equation 3) calculated the smallest signed and unsigned residuals from the difference between observed HRmax and predicted HRmax values for the significant main effects of equation (3), equation x sex (females x 3), and equation x activity level (active x 3). Therefore, based on our results, we conclude that HRmax = 208 – (0.7 ∙ age) has greater accuracy than the other two equations studied for predicting observed values of HRmax in 18-25 year olds

The Influence of a Morton\u27s Foot on Arch Characteristics in Minimally-Shod Runners

Please refer to the pdf version of the abstract located adjacent to the title

Effects of higher dietary protein and fiber intakes at breakfast on postprandial glucose, insulin, and 24-H interstitial glucose in overweight adults

Dietary protein and fiber independently influence insulin-mediated glucose control. However, potential additive effects are not well-known. Men and women (n = 20; age: 26 ± 5 years; body mass index: 26.1 ± 0.2 kg/m²; mean ± standard deviation) consumed normal protein and fiber (NPNF; NP = 12.5 g, NF = 2 g), normal protein and high fiber (NPHF; NP = 12.5 g, HF = 8 g), high protein and normal fiber (HPNF; HP = 25 g, NF = 2 g), or high protein and fiber (HPHF; HP = 25 g, HF = 8 g) breakfast treatments during four 2-week interventions in a randomized crossover fashion. On the last day of each intervention, meal tolerance tests were completed to assess postprandial (every 60 min for 240 min) serum glucose and insulin concentrations. Continuous glucose monitoring was used to measure 24-h interstitial glucose during five days of the second week of each intervention. Repeated-measures ANOVA was applied for data analyses. The HPHF treatment did not affect postprandial glucose and insulin responses or 24-h glucose total area under the curve (AUC). Higher fiber intake reduced 240-min insulin AUC. Doubling the amount of protein from 12.5 g to 25 g/meal and quadrupling fiber from 2 to 8 g/meal at breakfast was not an effective strategy for modulating insulin-mediated glucose responses in these young, overweight adults.T32 HL116276 - NHLBI NIH HHS; UL1 TR001108 - NCATS NIH HH

A Comparison of Self-Reported Pain Levels in Minimally-Shod vs Traditionally-Shod Runners

Please see the pdf version of the abstract

The Influence of Proximal versus Distal Strength on Balance Control in Athletes versus Non-Athletes

Please see the pdf version of the abstract

Genetic and environmental influences on eating behavior - a study of twin pairs reared apart or reared together

This study examined the relative influence of genetic versus environmental factors on specific aspects of eating behavior. Adult monozygotic twins (22 pairs and 3 singleton reared apart, 38 pairs and 9 singleton reared together, age 18-76 years, BMI 17-43 kg/m2) completed the Three Factor Eating Questionnaire. Genetic and environmental variance components were determined for the three eating behavior constructs and their subscales using model-fitting univariate and multivariate analyses. Unique environmental factors had a substantial influence on all eating behavior variables (explaining 45-71% of variance), and most strongly influenced external locus for hunger and strategic dieting behavior of restraint (explaining 71% and 69% of variance, respectively). Genetic factors had a statistically significant influence on only 4 variables: restraint, emotional susceptibility to disinhibition, situational susceptibility to disinhibition, and internal locus for hunger (heritabilities were 52%, 55%, 38% and 50%, respectively). Common environmental factors did not statistically significantly influence any variable assessed in this study. In addition, multivariate analyses showed that disinhibition and hunger share a common influence, while restraint appears to be a distinct construct. These findings suggest that the majority of variation in eating behavior variables is associated with unique environmental factors, and highlights the importance of the environment in facilitating specific eating behaviors that may promote excess weight gain.R01 AR046124 - NIAMS NIH HHS; R01 MH065322 - NIMH NIH HHS; T32 HL069772 - NHLBI NIH HHS; R37 DA018673 - NIDA NIH HHS; R01 DK073321 - NIDDK NIH HHS; R01 DA018673 - NIDA NIH HH

The Effect of Added Weight on Foot Anthropometry in Pregnant Women and Controls

Please refer to the pdf version of the abstract located adjacent to the title

Characterising youth with callous-unemotional traits and concurrent anxiety: evidence for a high-risk clinical group

Growing evidence supports the existence of two variants of youth with high callous-unemotional (CU) traits who present with markedly different risk profiles and outcomes, with potential implications for risk assessment and treatment formulation. So far, studies have identified variants of CU youth mainly using data-driven cluster approaches based on levels of CU traits and co-occurring anxiety. Yet, the extent to which this knowledge may be translated into clinical practice is unclear. To this end, the present study employed a severity-based, cut-off approach to systematically characterise CU groups across a range of clinically informative domains, including trauma history, psychiatric symptomatology, affective functioning, attachment style and behavioural risk. Analyses were based on multi-rated data from a community sample of high-risk youths (n = 155, M = 18 years). Consistent with previous studies, we found that, whereas variants show comparable levels of antisocial behaviour, those who present with both high CU and high anxiety report more severe childhood maltreatment, psychological distress, ADHD symptomatology and behavioural risk-including substance use, suicidal ideation and unsafe sex. In addition, these youth show greater attachment insecurity and affective dysregulation, as indexed by levels of irritability and alexithymia. Together, findings indicate that (1) trauma history is a key factor that differentiates variants of CU youth high vs. low on anxiety, and (2) differences in individual functioning across variants point to the need for tailored clinical assessment tools and intervention strategies. Importantly, the present findings indicate that variants of CU youth can be meaningfully differentiated using cut-off based approaches that parallel methods used in clinical assessments