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A study is presented which compares the measures of head impact frequency, location of head impact, and the kinematic responses to the impact before cases of immediate and delayed concussions were diagnosed in collegiate and high school football players. The study concludes the highest kinematic measurements are associated with the immediate diagnosis of concussion and the higher frequency of impact measurement is associated with delayed diagnosis. Topics include the Gadd severity index, players' history of head impact exposure (HIE), and Head Impact Telemetry (HIT) System helmets.

Research is presented which compares the severity and frequency of head impacts in football players with a focus on identifying the specificity, sensitivity, and accuracy of single-impact severity measures used for diagnosing head injury or concussion. The article notes the study's 1,208 subjects were from college and high school football teams and 95 were diagnosed with concussion. The study concludes the players sustained more severe impacts and more frequent impacts on days they played with diagnosed concussions.

The article provides information on the study about the effects of infractions taken from participation in youth ice hockey on biomechanical measures of head impact severity. It states that accelerometer-instrumented helmets were used to gather biomechanical measures relating to head impacts such as linear acceleration, rotational acceleration, and Head Impact Technology severity profile (HIT sp) that are sustained while participating in ice hockey on the sixteen adolescent Bantam-aged male ice hockey players. It shows that infraction was observed in 17.3 percent of all body collisions. It concludes that infractions result in higher measures of head impact severity than noninfraction collisions.

Abstract: PEG-amide vancomycin derivatives (V3 position) have been synthesized and found to behave as prodrugs in vivo, demonstrating anti-microbial activity in mice when challenged with Staphylococcus aureus. The corresponding PEG-carbamate derivatives do not manifest this in vivo activity, although both classes of compounds have similar in vitro rat plasma stability. Thus, it appears that extra vascular cleavage of the amide bond can occur if the condition of extended circulation of the conjugate is met, resulting in the release of vancomycin. [Copyright &y& Elsevier]

Two PEG prodrugs utilizing conjugation of PEG through the C-21 acid functionality as well as the C-17 OH group of CPT hydroxy-amide open forms were synthesized and characterized. Both of these open lactone tripartate prodrugs were shown to be water soluble and highly effective in MX-1 mouse xenograph studies. Indirect evidence implies that the initial ester or carbonate bond breaking is esterase mediated in the first step of the cascade of CPT release. [Copyright &y& Elsevier]

The current review presents an update of drug delivery using poly(ethylene glycol) (PEG), that focuses on recent developments in both protein and organic drugs. Certainly the past 10 years has resulted in a renaissance of the field of PEG drug conjugates, initiated by the use of higher molecular weight PEGs (Mw>20,000), especially 40,000 which is estimated to have a plasma circulating t1/2 of approximately 10 h in mice. This recent resuscitation of small organic molecule delivery by high molecular weight PEG conjugates was founded on meaningful in vivo testing using established tumor models, and has led to a clinical candidate, PEG-camptothecin (PROTHECAN®), an ester based prodrug currently in phase II trials. Additional applications of high molecular weight PEG prodrug strategies to amino containing drugs are presented: similar tripartate systems based on lower Mw PEG and their use with proteins is expounded on. The modification of a benzyl elimination tripartate prodrug specific for mercaptans is presented, and its successful application to 6-mercaptopurine giving a water soluble formulation is discussed. Recent novel PEG oligonucleotides and immunoconjugates are also covered. Clinical results of FDA approved PEGylated proteins are also presented. [Copyright &y& Elsevier]

Selective acylation of the phenolic hydroxyl group of 10-hydroxycamptothecin has been accomplished using phenyl dichlorophosphate. Additional modification of the 10-OH as an ether permits a 20-acyl derivative to be synthesized. This result along with data from a 6-hydroxyquinoline model strongly suggests that powerful intermolecular hydrogen bonding exists in the parent molecule. [Copyright &y& Elsevier]

Provides information on a study which compares the dynamic impact response of braced and unbraced cadaveric wrists using a commercially available wrist guard. Epidemiologic data of wrist injuries; Materials and methodology of the study; Results of the study.

Reports on the synthesis of polyethylene glycol (PEG) conjugated taxol linked via carbamate and carbonate functionalities. Preparation of nonpolymeric taxoids; Solubility of PEG-taxol derivatives; Use of methoxyacetate as a protecting group; Nuclear magnetic resonance studies of taxol derivatives.

The author presents a study on the technology used in monitoring head impact exposure in athletes who are wearing athletic headgear while engaging in contact sports. This technology is used in alerting medical personnel regarding athletes who are at risk of developing brain injury and who are in need of immediate medical attention. Athletes who reached a level of head impact exposure are subjected to medical evaluation and appropriate management for possible brain injury.

The relevance of the Bsmoc protecting group in the synthesis of moisture- and base-sensitive compounds has been demonstrated by the preparation of 2'-paclitaxel glycinate with use of the solid anhydrous base, 4-piperidinopiperidine in DCM solvent. [ABSTRACT FROM AUTHOR]

Reviewed: The Business of Benevolence: Industrial Paternalism in Progressive America. Tone, Andrea.

Reviewed: Labor's Great War: The Struggle for Industrial Democracy and the Origins of Modern American Labor Relations, 1912-1921. McCartin, Joseph A.

The purpose of this study was to quantify head impact exposure (frequency, location and magnitude of head impacts) for individual male and female collegiate ice hockey players and to investigate differences in exposure by sex, player position, session type, and team. Ninety-nine (41 male, 58 female) players were enrolled and 37,411 impacts were recorded over three seasons. Frequency of impacts varied significantly by sex (males: 287 per season, females: 170, p <0.001) and helmet impact location (p< 0.001), but not by player position (p=0.088). Head impact frequency also varied by session type; both male and female players sustained more impacts in games than in practices (p < 0.001), however the magnitude of impacts did not differ between session types. There was no difference in 95th percentile peak linear acceleration between sexes (males: 41.6 g, females: 40.8 g), but 95th percentile peak rotational acceleration and HITsp (a composite severity measure) were greater for males than females (4424, 3409 rad/s², and 25.6, 22.3, respectively). Impacts to the back of the helmet resulted in the greatest 95th percentile peak linear accelerations for males (45.2 g) and females (50.4 g), while impacts to the side and back of the head were associated with the greatest 95th percentile peak rotational accelerations (males: 4719, 4256 rad/sec², females: 3567, 3784 rad/sec² respectively). It has been proposed that reducing an individual's head impact exposure is a practical approach for reducing the risk of brain injuries. Strategies to decrease an individual athlete's exposure need to be sport and gender specific, with considerations for team and session type. [ABSTRACT FROM AUTHOR]

The wrist is the most frequently injured body region among snowboarders. Studies have shown that the risk of sustaining a wrist injury can be reduced by wearing wrist protection. Currently, there are a wide variety of wrist protection products for snowboarding on the market that offer a range of protective features. However, there are no minimum performance standards for snowboarding wrist protectors worldwide. The International Society for Skiing Safety convened a task force to develop a White Paper to evaluate the importance and necessity of a minimum performance for all wrist protectors used in snowboarding. The White Paper outlines the need for a general framework for a harmonized international standard and reviews the existing evidence. Therefore, this White Paper may serve as a common base for future discussions. The broader goal of developing and implementing such a standard is to reduce the incidence and the severity of wrist injuries in snowboarding without increasing the risk of adverse events, such as upper arm or shoulder injury. The European standard for inline skating wrist protectors (EN 14120) can serve as a starting point for efforts related to a standard for snowboard wrist protectors, but certain modifications to the standard would be required. It is hypothesized that implementation of a snowboarding wrist protector standard would result in fewer and less severe wrist injuries in the sport and could translate into more riding days for healthy snowboarders and significant health-care costs savings. [ABSTRACT FROM AUTHOR]

Abstract: Generating subject-specific, all-hexahedral meshes for finite element analysis continues to be of significant interest in biomechanical research communities. To date, most automated methods “morph” an existing atlas mesh to match with a subject anatomy, which usually result in degradation in mesh quality because of mesh distortion. We present an automated meshing technique that produces satisfactory mesh quality and accuracy without mesh repair. An atlas mesh is first developed using a script. A subject-specific mesh is generated with the same script after transforming the geometry into the atlas space following rigid image registration, and is transformed back into the subject space. By meshing the brain in 11 subjects, we demonstrate that the technique''s performance is satisfactory in terms of both mesh quality (99.5% of elements had a scaled Jacobian >0.6 while <0.01% were between 0 and 0.2) and accuracy (average distance between mesh boundary and geometrical surface was 0.07mm while <1% greater than 0.5mm). The combined computational cost for image registration and meshing was <4min. Our results suggest that the technique is effective for generating subject-specific, all-hexahedral meshes and that it may be useful for meshing a variety of anatomical structures across different biomechanical research fields. [Copyright &y& Elsevier]

Information about the topics discussed during the Ice Hockey Summit: Action on Concussion that was held at the Mayo Clinic in the U.S. in 2010 is presented. Papers presented at the summit focused on concussion in ice hockey, particularly the development of concussion reduction strategies in the sport. The attendees in the summit prioritized important evidence-based action items including rule changes and education of all coaches, players and parents.

The article offers information on the summit related to concussion in ice hockey. As stated, the objective of the summit was to integrate the concussion in sport literature and sport science research on safety in ice hockey to develop an action plan to reduce the risk, incidence, severity and consequences of concussion in ice hockey. Six components of a potential solution were articulated in a rationale paper and became the topics for breakout groups that followed the professional, scientific lectures.

Accelerations of the head are the likely cause of concussion injury; but identifying the specific etiology of concussion has been difficult due to the lack of a valid animal or computer model. Contact sports, in which concussions are a rising health care concern, offer a unique research laboratory' environment However; measuring head acceleration in the field has many challenges including the need for large population sampling because of the relatively low incidence of concussions. We report a novel approach for calculating linear acceleration that can be incorporated into a head-mounted system for on-field use during contact sports. The advantages of this approach include the use of single-axis linear accelerometers, which reduce costs; and a nonorthogonal arrangement of the accelerometers, which simplifies the design criteria for a head-mounted and helmet compatible system. The purpose of this study was to describe the algorithm and evaluate its accuracy for measuring linear acceleration magnitude and impact location using computer simulation and experimental tests with various accelerometer configurations. A 10% error in magnitude and a 10 deg error in impact location, were achieved using as Jew as six single-axis accelerometers mounted on a hemispherical headform. [ABSTRACT FROM AUTHOR]

The Ice Hockey Summit III provided updated scientific evidence on concussions in hockey to inform these five objectives: 1) describe sport-related concussion (SRC) epidemiology, 2) classify prevention strategies, 3) define objective, diagnostic tests, 4) identify treatment, and 5) integrate science and clinical care into prioritized action plans and policy. Our action plan evolved from 40 scientific presentations. The 155 attendees (physicians, athletic trainers, physical therapists, nurses, neuropsychologists, scientists, engineers, coaches, and officials) voted to prioritize these action items in the final Summit session. 1) Establish a national and international hockey data base for SRC at all levels, 2) eliminate body checking in Bantam youth hockey games, 3) expand a behavior modification program (Fair Play) to all youth hockey levels, 4) enforce game ejection penalties for fighting in Junior A and professional hockey leagues, 5) establish objective tests to diagnose concussion at point of care (POC), and 6) mandate baseline testing to improve concussion diagnosis for all age groups. Expedient implementation of the Summit III prioritized action items is necessary to reduce the risk, severity, and consequences of concussion in the sport of ice hockey. [ABSTRACT FROM AUTHOR]

A letter to the editor is presented in response to the article "Validation of a Helmet-Based System to Measure Head Impact Biomechanics in Ice Hockey" by M. A. Allison, Y. S. Kang, M. R. Maltese et al., which appeared in a previous issue.

Objectives: Head impact exposure (HIE) in youth football is a public health concern. The objective of this study was to determine if one season of HIE in youth football was related to cognitive changes. Method: Over 200 participants (ages 9–13) wore instrumented helmets for practices and games to measure the amount of HIE sustained over one season. Pre- and post-season neuropsychological tests were completed. Test score changes were calculated adjusting for practice effects and regression to the mean and used as the dependent variables. Regression models were calculated with HIE variables predicting neuropsychological test score changes. Results: For the full sample, a small effect was found with season average rotational values predicting changes in list-learning such that HIE was related to negative score change: standardized beta (β) = -.147, t(205) = -2.12, and p =.035. When analyzed by age clusters (9–10, 11–13) and adding participant weight to models, the R2 values increased. Splitting groups by weight (median split), found heavier members of the 9–10 cohort with significantly greater change than lighter members. Additionaly, significantly more participants had clinically meaningful negative changes: X2 = 10.343, p =.001. Conclusion: These findings suggest that in the 9–10 age cluster, the average seasonal level of HIE had inverse, negative relationships with cognitive change over one season that was not found in the older group. The mediation effects of age and weight have not been explored previously and appear to contribute to the effects of HIE on cognition in youth football players. [ABSTRACT FROM AUTHOR]

Background: Concern for head injuries is widespread and has been reported by the media to be the number one cause of decreased participation in football among the American youth population. Identifying player mechanisms associated with intentional, or purposeful, head impacts should provide critical data for rule modifications, educational programs, and equipment design. Purpose: To investigate the frequency of intentional and unintentional head impacts and to examine the player mechanisms associated with intentional high-magnitude head impacts by comparing the impact mechanism distributions among session type, player position, and ball possession. Study Design: Cross-sectional study; Level of evidence, 3. Methods: Head impact sensors and video footage of 68 players were used to analyze and classify 1319 high-magnitude impacts recorded over 1 season of youth football. Results: In total, 80% of the high-magnitude head impacts were classified as being caused by intentional use of the head. Head-to-head impact was the primary impact mechanism (n = 868; 82.7%) within the 1050 intentional high-magnitude impacts, with classifiable mechanisms, followed by head-to-body (n = 139; 13.2%), head-to-ground (n = 34; 3.2%), and head-to-equipment (n = 9; 0.9%). Head-to-head impacts also accounted for a greater proportion of impacts during practices (n = 625; 88.9%) than games, for linemen (n = 585; 90.3%) than perimeters and backs, and for ball carriers (n = 72; 79.1%) than tacklers. Conclusion: Overall, the majority of high-magnitude head impacts were intentional and resulted from head-to-head contact. The proportion of head-to-head contact was significantly higher for practices than games, linemen than backs and perimeter players, and ball carriers than tacklers. [ABSTRACT FROM AUTHOR]