This study investigated the cumulative effect of mild head injuries on rugby players. A comprehensive battery of neuropsychological tests was administered and subjects completed a self-report postconcussive symptom questionnaire. Data were collected for the two rugby groups, Springbok rugby players (n = 26) and Under 21 rugby players (n = 19), and for the control group, national hockey players (n = 21). Group comparisons of the percentage of individuals with deficit or self-reported symptomatology were made between: (i) the contact sport groups and the control group; (ii) the forwards and the backs within each rugby group and the rugby forwards and the control group; and (iii) the Springbok and Under 21 rugby players. Broadly speaking, comparative results on the neuropsychological tests and the self-reported postconcussive symptoms clearly distinguished between contact sport players and non-contact sport players and indicated the presence of diffuse brain damage in the contact sport players. There was also clear evidence of positional variation within the rugby groups, with the forwards (more full contact positions) most susceptible to impairment. Neuropsychological test results revealed deficit in information processing speed, attention and concentration, mental flexibility, visual memory and verbal new learning. The most significant neuropsychiatric complaints were reported in the areas of memory, social contact, sensitivity to noise, lowered frustration tolerance, anxiety and worry, and depression. The most sensitive neuropsychological test used in the present study was the Digit Symbol Substitution test. This test clearly distinguished contact sport players from non-contact sport players, and forwards from backs.

The objective of the study was to investigate the cumulative neurocognitive effects of repetitive concussive and subconcussive events in club level Rugby Union (hereafter rugby) during the course of one rugby season, in a combined group and individualized case-based approach. Amateur adult club level rugby players (n = 20) were compared with a non-contact control group (n = 22) of equivalent age, years of education and estimated IQ (p = > .05, in all instances), although the two groups were clearly differentiated on the basis of a history of reported concussions (p = < .05). Video analyses documented the tackling maneuvers observed amongst the players during all matches across the rugby season revealing a sobering average of more than a thousand tackles per player, excluding any contact practice sessions. Five rugby players (n = 5) who were observed to have a head jarring event were also isolated for individualized postconcussive follow-up analysis of their neurocognitive profiles. Measures included the ImPACT Verbal and Visual Memory, Visual Motor Speed and Reaction Time composites and the Purdue Pegboard. Independent and dependent statistical analyses were employed to compare the rugby versus control group neurocognitive test profiles at and between the three test intervals. Correlational analyses explored the association between concussion, tackling and neurocognitive test outcomes. Descriptive comparisons of individual neurocognitive test scores with normative data were employed for the case analyses. Taken together, the results implicated vulnerability amongst club rugby players on the motor and speeded tasks, with less robust indications on the memory tasks. While limited in terms of its small sample size, it is considered that the outcome of the study was rendered more robust by virtue of being methodologically multifaceted with heuristic implications for future research studies in the area. The novel inclusion of tackling data as well as fine-tuned case analyses, were of particular relevance in that regard. The results add to a growing body of literature that implicates deleterious neurocognitive effects in participants of a sport such as rugby due to repetitive head jarring incidents that are intrinsic to the game.

Ligament tears are more prevalent than all other knee injury pathologies, and contribute significantly to musculoskeletal joint pain and disability reported worldwide. Despite current soft tissue reconstruction techniques, the injured ligament fails to regenerate due to dysregulated cell-extracellular matrix (ECM) interactions that culminate in scar formation. Hallmarks of scar formation, or fibrotic healing include disorganized ECM, pathological stiffness or tissue rigidity, and the accumulation and persistence of myofibroblasts. A primary driver of fibrosis, myofibroblasts are characterized by high contractility, excessive deposition of collagen type I, coupled with inflammatory and fibrotic signaling. Notably these cells are critical early on in the response to injury, by aiding in the contracture of the wound bed and depositing collagen to repair the injury site. However, myofibroblasts are not capable of fully regenerating the native ligamentous matrix, and resolution of the phenotype is necessary in order to cue surrounding cells, prevent chronic inflammation and aberrant tissue remodeling. Persistence of the myofibroblast phenotype thus leads to a ligament scar that is functionally weaker than the healthy tissue matrix, characterized by significantly different histological, biochemical, and biomechanical properties. The consequential instability of this scar disrupts load distribution within the knee joint and increases the risk of subsequent injury, osteochondral degeneration, and ultimately, the development of post-traumatic osteoarthritis. Therefore, there is a critical need for strategies that target the inflammatory and fibrotic myofibroblast phenotypes for soft tissue healing. It follows that the overarching goal of this thesis is to engineer an immunomodulatory matrix to regulate myofibroblast activation and downstream fibrogenic signaling. To this end, models of soft tissue fibrotic repair are explored in order to test the central hypothesis that cues from the repairing ECM play an important role in regulating myofibroblast activation and persistence. Specifically, this thesis will compare myofibroblast differentiation and signaling in three in vitro models of tissue repair: 1) 2D on tissue culture polystyrene (TCPS), and two 3D models namely 2) collagen hydrogel and 3) electrospun collagen fiber matrices. As expected, on the 2D model, a persistent myofibroblast phenotype could be generated over time with an optimized transforming growth factor beta 1 (TGF-β1) stimulation protocol. To create repair-relevant 3D matrix models, we engineered collagen hydrogels with controlled mechanical properties, as well as electrospun fiber platforms that isolate key matrix factors including, collagen content, stiffness, fiber diameter, and alignment. These models emulate the connective tissue repair process via recapitulating the increasing matrix stiffness and fiber assembly of the early (granulation tissue), proliferative, and remodeling stages of the repair. Myofibroblast differentiation potential, parallel inflammatory and fibrotic cytokine secretion, as well as matrix remodeling potential were observed to be dependent on matrix model parameters. Moreover, single-cell resolution RNA sequencing revealed heterogenous myofibroblast populations within the context of response to engineered collagenous substrates. Specifically, myofibroblast accumulation was observed on hydrogel substrates that recapitulate the pathologically stiff mechanics and disorganization of fibrotic scar tissue while architectural cues of engineered fiber substrates prevented myofibroblast differentiation in a diameter and alignment-dependent manner. Moreover, nanoscale fibers elicited the greatest anti-fibrotic and anti-inflammatory properties compared to microscale fibers and stiff collagen-based hydrogels. Throughout, this thesis also explores the contribution of NF-κB signaling to myofibroblast plasticity and persistence using engineered collagen-based platforms, highlighting the dynamic role of myofibroblasts as critical immunoregulating cells. The NF-κB signaling pathway is implicated in a broad array of fibrotic and chronic inflammatory conditions, and more recently has been associated with survival of persistent myofibroblast populations in soft-tissue fibrosis and tendon degeneration models. In this thesis, NF-κB activation was seen to be related to the persistent myofibroblast phenotype and increase over time in both 2D TCPS and 3D collagenous hydrogel matrices that mimic pathologically stiff scar tissue, while a temporally dependent activation pattern was observed in electrospun collagen fiber-based models. At the transcriptional level, NF-κB survival signaling was significantly enriched in myofibroblast populations supported by TCPS and stiff collagen-based hydrogels but downregulated on soft hydrogels and fibers with decreasing fiber diameter that prevented robust myofibroblast differentiation at single cell resolution. Building upon these new insights regarding matrix cues that drive myofibroblast activation, we designed an immunomodulatory matrix that mediates small molecule release targeting NF-κB inhibition. The immunomodulatory matrix achieved robust amelioration of the myofibroblast phenotype as well as reduced the secretion of key inflammatory and fibrotic cytokines by these cells. Moreover, a similar anti-fibrotic response was seen for human ligament fibroblasts treated with these matrices. Collectively, this thesis work presents a systematic evaluation of myofibroblast plasticity and persistence within the context of 2D (TCPS), 3D (collagen-based hydrogels), and finally 3D with defined microarchitectural cues (electrospun collagen-based fibers) that recapitulate the progressive stages of scar-mediated healing, and reveals NF-κB as a promising target for reducing myofibroblast persistence. Moreover, the immunomodulatory control of myofibroblast plasticity and persistence via matrix cues coupled with NF-κB inhibition informs future strategies for true ligament healing.

This study was conducted as a second part in the shear damage research project at Virginia Tech. The objectives were to verify the results obtained by Gallagher (1984) in the first study under normal mill operations as well as develop a method to compare and evaluate the extent of shear damage in relation to other defects present in southern pine lumber. This was accomplished through two sawmill studies and two kiln cart surveys performed in different geographic locations. Visible indicators such as stump-pull that are used to determine shear damage extent are often misleading. Stump-pull, used as a scaling deduction for shear damage, does not fully determine the extent of shear damage present. Shatter is often present in greater amounts over the cross section of the butt of the log. The recommendation of six inches of butt trim that was determined to minimize value losses in the first study is supported by the results obtained in this research. A trim of six inches removed 94 to 99 percent of shear damage in this study. Defects other than shear damage were present on dried and surfaced lumber. Drying checks and splits along with shake were often observed on the lumber ends. These defects often extend further up on the lumber ends, past the seven inch simulated trim. Shake was determined to be the limiting defect. Shatter, in the absence of shake, was determined to be limiting. Kiln cart surveys conducted at mills that utilize a large percentage of sheared logs can be an inexpensive and effective tool to enable mill personnel to determine the extent of shear damage in relation to other defects present on lumber ends based on green trim already taken. / Master of Science

Mini-dissertation submitted in partial compliance with the requirements for the Master’s Degree in Technology: Chiropractic, Durban University of Technology, 2012. / Purpose: Patellofemoral Pain Syndrome is a common condition in all age groups, with a multifactorial etiology. This study aimed to investigate the association between the Quadriceps femoris muscle group, Hamstring muscle group and Adductor muscle group, and to establish the relationship between myofascial trigger points (MFTP’s) in these muscle groups and patellofemoral pain syndrome (PFPS). Methods: A cross-sectional, observational, quantitative non-intervention clinical assessment study was conducted at the Chiropractic Day Clinic at Durban University of Technology (DUT), to determine the extent of the PFPS, the MFTPs and thus the relationship between the two. The study included eighty patients with PFPS, who were recruited by convenience sampling. The results were captured using Microsoft excel and SPSS version 15.0 was used to analyze the data. Results: Quadriceps femoris muscle group MFTPs were noted in 92.5% of the patients (most prevalent being Vastus medialis TP1 (63.8%), Vastus lateralis TP1 (33.8%) and Vastus intermedius at 27,5%). Least common was Vastus lateralis TP2 only presenting in 2,5% of the patients. Hamstring muscle group MFTPs were found overall in 86.3% of patients (most prevalent being in Biceps femoris muscle (66%), and least prevalent being in Semitendinosus muscle (11,3%)). MFTPs were present in 64% overall of the Adductor muscle group (Adductor magnus muscle being the most common). Significant associations were made between the presence of MFTPs in the Vastus lateralis TP2 (p=0.00), Vastus medialis TP1 (p=0.046; 0.005; 0.004), the NRS and the PPSS. Also significant was the relationship between the NRS, PPSS and the Semimembranosus and Adductor magnus muscles indicated that these muscles were the most likely causes of pain even though they had fewer MFTPs than other comparable muscles. Conclusion: The outcomes of this study supports previous research indicating that an extensor dysfunction of the Quadriceps femoris muscle group may be of MFTP origin and indicates that other muscles in the thigh require further research indicating their role in the development of PFPS.

A direct bone tendon junction consists of four zones: tendon, uncalcified fibrocartilage, calcified fibrocartilage, and bone. The uncalcified and calcified fibrocartilage together forms the transition zone. This organization ensures a gradual transition in stiffness and material properties, and protects the junction from failure. Transition zone regeneration during bone tendon junction healing is important to restore this unique protective mechanism. / Bone tendon junction repair is involved in many orthopaedic reconstructive procedures. Healing is observed to be slow. The junction often heals by fibrous tissue formation. Previous attempts to enhance bone tendon junction healing have resulted in increased bone formation. However, fibrocartilage transition zone is not restored. / This thesis describes a series of studies on transition zone regeneration in bone tendon junction healing using two partial patellectomy animal models. The healing process inside a bone trough was first studied and characterized. Little transition zone regeneration was observed except near the articular cartilage cut surface. The possibility of using articular cartilage to stimulate transition zone regeneration was explored. Both articular cartilage autograft and allogeneic cultured chondrocyte pellet implantations resulted in significantly increased fibrocartilage transition zone regeneration. Cell tracking indicated that the regenerated tissue likely originated from host cells. To elucidate the mechanism of stimulation by allogeneic cultured chondrocyte pellet, the role of cellular and matrix component needed to be differentiated. Freezing and rapid freeze thaw cycles permanently devitalized the allogeneic cultured chondrocyte pellet, but retained its structural integrity and matrix contents. Preliminary results indicated that implantation of the devitalized allogeneic cultured chondrocyte pellet could still increase fibrocartilage transition zone regeneration. Cellular activity seemed not to be essential for the stimulatory effect. / With further research and development, it is envisioned that a cartilage-based stimulation method for fibrocartilage transition zone regeneration in bone tendon junction healing will be developed for clinical application. / Wong Wan Nar, Margaret. / Source: Dissertation Abstracts International, Volume: 70-06, Section: B, page: 3423. / Thesis (M.D.)--Chinese University of Hong Kong, 2008. / Includes bibliographical references (leaves 216-231). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstracts in English and Chinese. / School code: 1307.

published_or_final_version / Psychiatry / Master / Master of Philosophy

The prefrontal cortex (PFC) has long been thought to be the seat of social behaviours in mammals. Lesions of the orbitofrontal cortex (OFC), a subregion of the PFC, are known to cause social deficits in humans. Interestingly, social deficits are also seen in rats with OFC lesions. Rats that are deprived of peer play during development exhibit behaviour similar to OFC-ablated animals. Another subregion of the PFC, the medial prefrontal cortex (mPFC) is interconnected with the OFC. The mPFC and OFC have been shown to be reciprocally responsive to a variety of inuences, in terms of dendritic morphology. It was hypothesized that social experiences are necessary for the proper development of the OFC, and that, because of the interconnectivity, the mPFC would also be sensitive to social experience. The social condition in which juvenile rats were raised was manipulated, and the OFC and mPFC were shown to be differentially responsive to specific aspects of social experience. It was already known that OFC lesions produce specific social deficits, but the contribution of the mPFC to the production of social behaviour was unknown. To investigate the contribution of the mPFC to the performance of social behaviour, animals were given mPFC lesions, and their social play behaviour was quantified. mPFC-ablated animals had altered play patterns that were distinct from those seen in the OFC-ablated animals. It was concluded that the OFC and mPFC are differentially responsive to social stimuli during development, and that the OFC and mPFC make discrete contributions to the production of social behaviour. The results were interpreted in an evolutionary context. / x, 93 leaves : ill. ; 29 cm.

Participation in athletics is a popular pastime and form of entertainment. Children often begin to specialize in one sport at a young age in an effort to excel, which increases physical stress and the potential for injuries. Athletes participating in overhead sports are at increased risk of upper body chronic injuries, in part because the shoulder is an unstable hypermobile joint. Posture may also be affected in these athletes because of the demands placed on the upper body. The purpose of this study was to measure the upper body posture in a sample of Division I collegiate volleyball and softball athletes to investigate the prevalence of postural abnormalities and their relationship to pain or injury. Twenty-one Division I collegiate female athletes (seven volleyball; fourteen softball) who participated in their sport during the fall 2014 to spring 2015 seasons were studied. Athletes completed a pain and injury questionnaire, after which individual upper body posture measurements were made. Measurements included resting bilateral scapula position, head position, and shoulder position. An iPad mini camera was used with a commercial application (PostureCo, Inc.) to perform a photographic plumb line posture assessment with photographs taken in anterior, posterior, and lateral views. Posture analysis revealed a high prevalence (85.7 %) of forward head posture in this sample. Forward shoulder was noted in 42.9 % of the athletes and abnormal horizontal scapula position appeared to occur more frequently in the dominant arm (71.4 %) than in the non-dominant arm (47.6 %). Chi square tests determined that there was no statistically significant relationship between posture abnormalities and self-reported pain in this group of athletes. Results of this study -- although preliminary -- should be used to inform future research to investigate potential relationships between posture and pain/injury in overhead athletes.

Digitized by Kansas Correctional Industries