Identification of novel mutations in X-linked retinitis pigmentosa families and implications for diagnostic testing

PURPOSE: The goal of this study was to identify mutations in X-chromosomal genes associated with retinitis pigmentosa (RP) in patients from Germany, The Netherlands, Denmark, and Switzerland. METHODS: In addition to all coding exons of RP2, exons 1 through 15, 9a, ORF15, 15a and 15b of RPGR were screened for mutations. PCR products were amplified from genomic DNA extracted from blood samples and analyzed by direct sequencing. In one family with apparently dominant inheritance of RP, linkage analysis identified an interval on the X chromosome containing RPGR, and mutation screening revealed a pathogenic variant in this gene. Patients of this family were examined clinically and by X-inactivation studies. RESULTS: This study included 141 RP families with possible X-chromosomal inheritance. In total, we identified 46 families with pathogenic sequence alterations in RPGR and RP2, of which 17 mutations have not been described previously. Two of the novel mutations represent the most 3'-terminal pathogenic sequence variants in RPGR and RP2 reported to date. In exon ORF15 of RPGR, we found eight novel and 14 known mutations. All lead to a disruption of open reading frame. Of the families with suggested X-chromosomal inheritance, 35% showed mutations in ORF15. In addition, we found five novel mutations in other exons of RPGR and four in RP2. Deletions in ORF15 of RPGR were identified in three families in which female carriers showed variable manifestation of the phenotype. Furthermore, an ORF15 mutation was found in an RP patient who additionally carries a 6.4 kbp deletion downstream of the coding region of exon ORF15. We did not identify mutations in 39 sporadic male cases from Switzerland. CONCLUSIONS: RPGR mutations were confirmed to be the most frequent cause of RP in families with an X-chromosomal inheritance pattern. We propose a screening strategy to provide molecular diagnostics in these families.

Differential spatial and structural organization of the X chromosome underlies dosage compensation in C. elegans.

The adjustment of X-linked gene expression to the X chromosome copy number (dosage compensation [DC]) has been widely studied as a model of chromosome-wide gene regulation. In Caenorhabditis elegans, DC is achieved by twofold down-regulation of gene expression from both Xs in hermaphrodites. We show that in males, the single X chromosome interacts with nuclear pore proteins, while in hermaphrodites, the DC complex (DCC) impairs this interaction and alters X localization. Our results put forward a structural model of DC in which X-specific sequences locate the X chromosome in transcriptionally active domains in males, while the DCC prevents this in hermaphrodites.

The role of spatial and temporal radiation deposition in inertial fusion chambers: the case of HiPER¿

The first wall armour for the reactor chamber of HiPER will have to face short energy pulses of 5 to 20 MJ mostly in the form of x-rays and charged particles at a repetition rate of 5–10 Hz. Armour material and chamber dimensions have to be chosen to avoid/minimize damage to the chamber, ensuring the proper functioning of the facility during its planned lifetime. The maximum energy fluence that the armour can withstand without risk of failure, is determined by temporal and spatial deposition of the radiation energy inside the material. In this paper, simulations on the thermal effect of the radiation–armour interaction are carried out with an increasing definition of the temporal and spatial deposition of energy to prove their influence on the final results. These calculations will lead us to present the first values of the thermo-mechanical behaviour of the tungsten armour designed for the HiPER project under a shock ignition target of 48 MJ. The results will show that only the crossing of the plasticity limit in the first few micrometres might be a threat after thousands of shots for the survivability of the armour.

Identification of auxin-responsive elements of parB and their expression in apices of shoot and root.

Detailed analysis of transgenic tobaccos containing a series of chimeric parB promoter/beta-glucuronidase (GUS) gene constructs allowed us to define two auxin-responsive elements (AREs) of 48 bp and 95 bp (positions -210 to -163 and -374 to -280) in the parB promoter. The two AREs responded independently to physiological concentrations of auxin. Gel retardation assays revealed binding of nuclear protein(s) to the sequence conserved between ARE I and ARE II. The auxin responsiveness of the parB promoter did not mediate the pathway through the as-1 element and transcription factor ASF-1. AREs I and II were responsive to auxin at physiological concentrations, whereas as-1 responded only to higher concentrations of auxin which may be interpreted as stress, though as-1 had been reported to be a minimal ARE [Liu, X. & Lam, E. (1994) J. Biol. Chem. 269, 668-675]. Histochemical staining of transgenic tobacco that contained a parB promoter/GUS construct demonstrated the expression of GUS activity in the shoot apex as well as in the root tips, suggesting the involvement of parB expression in meristematic activity or differentiation. The drastic change in auxin responsiveness in the transgenic plants between the 6th and 10th day after imbibition of seeds implies the development or the activation of auxin signal transduction systems during plant development.

Caracterização in vitro do metabolismo e da absorção intestinal da casearina X

As principais propriedades farmacológicas da Casearia sylvestris, uma espécie de árvore cujas folhas são utilizadas na medicina popular, já foram descritas na literatura. Recentemente foi demonstrada a potente atividade citotóxica in vitro da casearina X (CAS X), o diterpeno clerodânico majoritário isolado das folhas de C. sylvestris, contra linhagens de células tumorais humanas. Apesar dos resultados promissores, sua potente atividade citotóxica in vitro não pode ser extrapolada para uma potente atividade in vivo, a menos que possua boa biodisponibilidade e duração desejável do seu efeito. Tendo em vista que o avanço nas pesquisas de produtos naturais requer a avaliação pré-clínica de propriedades farmacocinéticas, no presente trabalho foi realizada a caracterização in vitro do metabolismo e da absorção intestinal da CAS X, com o objetivo de prever sua biodisponibilidade in vivo. Para os estudos de metabolismo in vitro, foi utilizado o modelo microssomal hepático de ratos e de humanos. Foi desenvolvido um método analítico para a quantificação da CAS X em microssomas, empregando a precipitação de proteínas com acetonitrila no preparo das amostras e a cromatografia líquida de alta eficiência para as análises. O método foi validado de acordo com os guias oficiais da Agência Nacional de Vigilância Sanitária e da European Medicine Agency (EMA). A CAS X demonstrou ser substrato para as reações de hidrólise mediada pelas carboxilesterases (CES) e apresentou um perfil cinético de Michaelis-Menten. Foram estimados os parâmetros de Vmax e KM, demonstrando que o clearance intrínseco em microssomas hepático de humanos foi 1,7 vezes maior que o de ratos. O clearance hepático foi estimado por extrapolação in vitro-in vivo, resultando em mais de 90% do fluxo sanguíneo hepático em ambas as espécies. Um estudo qualitativo para a pesquisa de metabólitos foi feito utilizando espectrometria de massas, pelo qual foi possível sugerir a formação da casearina X dialdeído como produto de metabolismo. Nos estudos de absorção intestinal in vitro foi utilizado o modelo de monocamadas de células Caco-2. Um método analítico por cromatografia líquida acoplada a espectrometria de massas foi desenvolvido e validado de acordo com o EMA, para as etapas de quantificação da CAS X no sistema de células. Os parâmetros cinéticos de permeabilidade aparente absortiva e secretória da CAS X foram estimados em um sistema celular, no qual a atividade hidrolítica da CES foi inibida. Assim, a CAS X foi capaz de permear a monocamada de células Caco-2, provavelmente por transporte ativo, sem a ocorrência de efluxo, mas com significativa retenção do composto dentro das células. Em conjunto, os ensaios in vitro realizados demonstraram a susceptibilidade da CAS X ao metabolismo de primeira passagem, como substrato para as CES específicas expressas no fígado e intestino.

Individuazione del danno su ponti in muratura mediante misure dinamiche

La diagnostica strutturale è un campo in continuo sviluppo e attualmente sono numerosi gli studi tendenti alla definizione di tecniche e metodi in grado di fornire parametri che possano identificare, in modo sempre più accurato, lo stato di sicurezza di una struttura. Stato di sicurezza è un termine globale che si riferisce alla capacità portante di una struttura e alla sua resistenza alle sollecitazioni esterne, siano esse statiche o dinamiche. Per tanto, un qualsiasi danneggiamento strutturale potrebbe in varia misura influenzare tale stato. Per quanto riguarda i ponti stradali, negli ultimi anni l’attenzione è stata focalizzata allo studio di metodi di individuazione del danno a partire dai risultati ottenuti dal monitoraggio delle vibrazioni mediante accelerometri. Questo è stato possibile grazie agli avanzamenti raggiunti nell’identificazione modale e nei sensori per il monitoraggio strutturale. Questo lavoro si pone come obiettivo quello di proporre una nuova metodologia di analisi dei dati ottenuti da indagini sperimentali che possono essere svolte in sito. La definizione di tale metodologia è affidata a simulazioni numeriche volte a rappresentare stati di danneggiamento avanzati su elementi strutturali. In una prima fase verranno analizzati elementi semplificati rappresentativi di strutture esistenti, come ad esempio travi da ponte in calcestruzzo armato. In una seconda fase, il metodo verrà testato su modelli più complessi che tengano conto della tridimensionalità del problema, oltre alle variazioni sezionali e di materiali degli elementi che lo compongono.

From F energy rating to Nearly ZEB: project of energy retrofit and architectural upgrade of a brick terraced house in Co. Dublin, Ireland

Questo progetto è stato sviluppato durante un periodo di ricerca presso il Dipartimento di Ingegneria Civile del Trinity College e continuato presso l’Università di Bologna. Il progetto ha l’obiettivo di analizzare le soluzioni per l’ampliamento, la sostituzione degli impianti e l’ottimizzazione energetica di un tipico edificio residenziale Irlandese, una end of terrace in mattoni costruita negli anni ’20, collocata a Blackrock (Dublino). Diversi studi sostengono che lo stock abitativo irlandese è il peggiore del nord Europa per quanto riguarda la performance energetica. Questa tesi consta di una prima parte di studio del contesto e delle tecniche costruttive tradizionali irlandesi; è presente un capitolo di approfondimento sulle leggi riguardanti le costruzioni e gli incentivi forniti dal governo irlandese per interventi di retrofit energetico. Il terzo capitolo è un’analisi dell'esistente, con disegni del rilievo geometrico, immagini dell’edificio originale, termogrammi e dati riguardanti l’attuale performance energetica. Vengono poi mostrate diverse ipotesi di progetto e, una volta determinata la disposizione degli spazi interni, vengono considerate due soluzioni simili, ma costruite con pacchetti costruttivi diversi. Nel Progetto A l’involucro dell’addizione ha una struttura in muratura, nel Progetto B la struttura è in X-lam. Le performance energetiche delle due proposte vengono confrontate tramite una simulazione attuata grazie all'utilizzo del software dinamico IES-VE. Viene valutata l’applicazione di energie rinnovabili, quali l’energia solare e eolica e l’apporto che queste possono dare al bilancio energetico. Infine viene fatta un’analisi dei costi, valutando possibili suddivisioni dei lavori e ipotizzando un piano di ritorno dell’investimento, anche in combinazione con l’applicazione di energie rinnovabili. Alla fine del progetto si trova una valutazione quantitativa dei miglioramenti dell’edificio e un’analisi critica dei limiti del progetto.

Microfluidic platforms for the characterization of in meso membrane protein crystallization

Membrane proteins, which reside in the membranes of cells, play a critical role in many important biological processes including cellular signaling, immune response, and material and energy transduction. Because of their key role in maintaining the environment within cells and facilitating intercellular interactions, understanding the function of these proteins is of tremendous medical and biochemical significance. Indeed, the malfunction of membrane proteins has been linked to numerous diseases including diabetes, cirrhosis of the liver, cystic fibrosis, cancer, Alzheimer's disease, hypertension, epilepsy, cataracts, tubulopathy, leukodystrophy, Leigh syndrome, anemia, sensorineural deafness, and hypertrophic cardiomyopathy.1-3 However, the structure of many of these proteins and the changes in their structure that lead to disease-related malfunctions are not well understood. Additionally, at least 60% of the pharmaceuticals currently available are thought to target membrane proteins, despite the fact that their exact mode of operation is not known.4-6 Developing a detailed understanding of the function of a protein is achieved by coupling biochemical experiments with knowledge of the structure of the protein. Currently the most common method for obtaining three-dimensional structure information is X-ray crystallography. However, no a priori methods are currently available to predict crystallization conditions for a given protein.7-14 This limitation is currently overcome by screening a large number of possible combinations of precipitants, buffer, salt, and pH conditions to identify conditions that are conducive to crystal nucleation and growth.7,9,11,15-24 Unfortunately, these screening efforts are often limited by difficulties associated with quantity and purity of available protein samples. While the two most significant bottlenecks for protein structure determination in general are the (i) obtaining sufficient quantities of high quality protein samples and (ii) growing high quality protein crystals that are suitable for X-ray structure determination,7,20,21,23,25-47 membrane proteins present additional challenges. For crystallization it is necessary to extract the membrane proteins from the cellular membrane. However, this process often leads to denaturation. In fact, membrane proteins have proven to be so difficult to crystallize that of the more than 66,000 structures deposited in the Protein Data Bank,48 less than 1% are for membrane proteins, with even fewer present at high resolution (< 2Å)4,6,49 and only a handful are human membrane proteins.49 A variety of strategies including detergent solubilization50-53 and the use of artificial membrane-like environments have been developed to circumvent this challenge.43,53-55 In recent years, the use of a lipidic mesophase as a medium for crystallizing membrane proteins has been demonstrated to increase success for a wide range of membrane proteins, including human receptor proteins.54,56-62 This in meso method for membrane protein crystallization, however, is still by no means routine due to challenges related to sample preparation at sub-microliter volumes and to crystal harvesting and X-ray data collection. This dissertation presents various aspects of the development of a microfluidic platform to enable high throughput in meso membrane protein crystallization at a level beyond the capabilities of current technologies. Microfluidic platforms for protein crystallization and other lab-on-a-chip applications have been well demonstrated.9,63-66 These integrated chips provide fine control over transport phenomena and the ability to perform high throughput analyses via highly integrated fluid networks. However, the development of microfluidic platforms for in meso protein crystallization required the development of strategies to cope with extremely viscous and non-Newtonian fluids. A theoretical treatment of highly viscous fluids in microfluidic devices is presented in Chapter 3, followed by the application of these strategies for the development of a microfluidic mixer capable of preparing a mesophase sample for in meso crystallization at a scale of less than 20 nL in Chapter 4. This approach was validated with the successful on chip in meso crystallization of the membrane protein bacteriorhodopsin. In summary, this is the first report of a microfluidic platform capable of performing in meso crystallization on-chip, representing a 1000x reduction in the scale at which mesophase trials can be prepared. Once protein crystals have formed, they are typically harvested from the droplet they were grown in and mounted for crystallographic analysis. Despite the high throughput automation present in nearly all other aspects of protein structure determination, the harvesting and mounting of crystals is still largely a manual process. Furthermore, during mounting the fragile protein crystals can potentially be damaged, both from physical and environmental shock. To circumvent these challenges an X-ray transparent microfluidic device architecture was developed to couple the benefits of scale, integration, and precise fluid control with the ability to perform in situ X-ray analysis (Chapter 5). This approach was validated successfully by crystallization and subsequent on-chip analysis of the soluble proteins lysozyme, thaumatin, and ribonuclease A and will be extended to microfluidic platforms for in meso membrane protein crystallization. The ability to perform in situ X-ray analysis was shown to provide extremely high quality diffraction data, in part as a result of not being affected by damage due to physical handling of the crystals. As part of the work described in this thesis, a variety of data collection strategies for in situ data analysis were also tested, including merging of small slices of data from a large number of crystals grown on a single chip, to allow for diffraction analysis at biologically relevant temperatures. While such strategies have been applied previously,57,59,61,67 they are potentially challenging when applied via traditional methods due to the need to grow and then mount a large number of crystals with minimal crystal-to-crystal variability. The integrated nature of microfluidic platforms easily enables the generation of a large number of reproducible crystallization trials. This, coupled with in situ analysis capabilities has the potential of being able to acquire high resolution structural data of proteins at biologically relevant conditions for which only small crystals, or crystals which are adversely affected by standard cryocooling techniques, could be obtained (Chapters 5 and 6). While the main focus of protein crystallography is to obtain three-dimensional protein structures, the results of typical experiments provide only a static picture of the protein. The use of polychromatic or Laue X-ray diffraction methods enables the collection of time resolved structural information. These experiments are very sensitive to crystal quality, however, and often suffer from severe radiation damage due to the intense polychromatic X-ray beams. Here, as before, the ability to perform in situ X-ray analysis on many small protein crystals within a microfluidic crystallization platform has the potential to overcome these challenges. An automated method for collecting a "single-shot" of data from a large number of crystals was developed in collaboration with the BioCARS team at the Advanced Photon Source at Argonne National Laboratory (Chapter 6). The work described in this thesis shows that, even more so than for traditional structure determination efforts, the ability to grow and analyze a large number of high quality crystals is critical to enable time resolved structural studies of novel proteins. In addition to enabling X-ray crystallography experiments, the development of X-ray transparent microfluidic platforms also has tremendous potential to answer other scientific questions, such as unraveling the mechanism of in meso crystallization. For instance, the lipidic mesophases utilized during in meso membrane protein crystallization can be characterized by small angle X-ray diffraction analysis. Coupling in situ analysis with microfluidic platforms capable of preparing these difficult mesophase samples at very small volumes has tremendous potential to enable the high throughput analysis of these systems on a scale that is not reasonably achievable using conventional sample preparation strategies (Chapter 7). In collaboration with the LS-CAT team at the Advanced Photon Source, an experimental station for small angle X-ray analysis coupled with the high quality visualization capabilities needed to target specific microfluidic samples on a highly integrated chip is under development. Characterizing the phase behavior of these mesophase systems and the effects of various additives present in crystallization trials is key for developing an understanding of how in meso crystallization occurs. A long term goal of these studies is to enable the rational design of in meso crystallization experiments so as to avoid or limit the need for high throughput screening efforts. In summary, this thesis describes the development of microfluidic platforms for protein crystallization with in situ analysis capabilities. Coupling the ability to perform in situ analysis with the small scale, fine control, and the high throughput nature of microfluidic platforms has tremendous potential to enable a new generation of crystallographic studies and facilitate the structure determination of important biological targets. The development of platforms for in meso membrane protein crystallization is particularly significant because they enable the preparation of highly viscous mixtures at a previously unachievable scale. Work in these areas is ongoing and has tremendous potential to improve not only current the methods of protein crystallization and crystallography, but also to enhance our knowledge of the structure and function of proteins which could have a significant scientific and medical impact on society as a whole. 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Confronto tra le tecniche XRD e IHD per la misura di tensioni residue

Le rotture a fatica dei componenti sono dovute principalmente alle tensioni di trazione generate da carichi ciclici e variabili nel tempo. Le cricche causate da questo tipo di tensioni possono propagarsi e crescere fino a causare danni catastrofici nel componente. La fatica costituisce uno dei fattori principali di rottura delle strutture aeronautiche; in campo aeronautico sono quindi molto diffusi dei trattamenti superficiali che permettono di indurre tensioni di compressione che contrastano quelle di trazione, in modo tale da ritardare o prevenire le rotture dovute al fenomeno della fatica. Esistono diverse tecniche per raggiungere questo risultato e permettere di prolungare la vita a fatica di un componente metallico, la più nota è sicuramente il Laser Shock Peening (LSP). Nel corso degli ultimi anni la maggior parte delle ricerche condotte rispetto a questa tecnica sono state incentrate sugli effetti meccanici che questo trattamento ha sul materiale in modo da determinare la configurazione ottimale per ottenere una distribuzione delle tensioni il più efficace possibile ai fini della vita a fatica; sono state svolte diverse prove sperimentali per studiare il ruolo dei parametri del laser e ottimizzare la procedura del LSP. Tra le tecniche utilizzate per valutare gli effetti del LSP in termini di tensioni residue, spiccano, oltre ai metodi computazionali, l'X-ray Diffraction (XRD) e l'Incremental Hole Drilling (IHD). L'elaborato di tesi qui presentato ha come scopo il confronto tra i livelli di tensioni residue riscontrate all'interno di provini sottili in lega di alluminio, sottoposti a differenti trattamenti laser, attraverso i suddetti metodi XRD e IHD. I risultati, già noti, ottenuti con la tecnica l'XRD sono stati posti a verifica attraverso dei test svolti con l'IHD presso i laboratori MaSTeRLab della Scuola di Ingegneria dell'Università di Bologna.

Uptake of an OHS code of practice by construction firms : barriers and enablers in an Australian industry

The Australian construction industry, reflecting a global trend, is moving towards the implementation of a voluntary code of practice (hereafter VCP) for occupational health and safety. The evidence suggests that highlyvisible clients and project management firms, in addition to their subcontractors, look set to embrace such a code. However, smaller firms not operating in high-profile contracting regimes may prove reticent to adopt a VCP. This paper incorporates qualitative data from a high-profile research project commissioned by Engineers Australia and supported by the Australian Contractors’ Association, Property Council of Australia, Royal Australian Institute of Architects, Association of Consulting Engineers Australia, Australian Procurement and Construction Council, Master Builders Australia and the Australian CRC for Construction Innovation. The paper aims to understand the factors that facilitate or prevent the uptake of the VCP by smaller firms, together with pathways to the adoption of a VCP by industry.

Labour rights as human rights : workers' safety at work in Australian-based supply chains

The increase of buyer-driven supply chains, outsourcing and other forms of non-traditional employment has resulted in challenges for labour market regulation. One business model which has created substantial regulatory challenges is supply chains. The supply chain model involves retailers purchasing products from brand corporations who then outsource the manufacturing of the work to traders who contract with factories or outworkers who actually manufacture the clothing and textiles. This business model results in time and cost pressures being pushed down the supply chain which has resulted in sweatshops where workers systematically have their labour rights violated. Literally millions of workers work in dangerous workplaces where thousands are killed or permanently disabled every year. This thesis has analysed possible regulatory responses to provide workers a right to safety and health in supply chains which provide products for Australian retailers. This thesis will use a human rights standard to determine whether Australia is discharging its human rights obligations in its approach to combating domestic and foreign labour abuses. It is beyond this thesis to analyse Occupational Health and Safety (OHS) laws in every jurisdiction. Accordingly, this thesis will focus upon Australian domestic laws and laws in one of Australia’s major trading partners, the Peoples’ Republic of China (China). It is hypothesised that Australia is currently breaching its human rights obligations through failing to adequately regulate employees’ safety at work in Australian-based supply chains. To prove this hypothesis, this thesis will adopt a three- phase approach to analysing Australia’s regulatory responses. Phase 1 will identify the standard by which Australia’s regulatory approach to employees’ health and safety in supply chains can be judged. This phase will focus on analysing how workers’ rights to safety as a human right imposes a moral obligation on Australia to take reasonablely practicable steps regulate Australian-based supply chains. This will form a human rights standard against which Australia’s conduct can be judged. Phase 2 focuses upon the current regulatory environment. If existing regulatory vehicles adequately protect the health and safety of employees, then Australia will have discharged its obligations through simply maintaining the status quo. Australia currently regulates OHS through a combination of ‘hard law’ and ‘soft law’ regulatory vehicles. The first part of phase 2 analyses the effectiveness of traditional OHS laws in Australia and in China. The final part of phase 2 then analyses the effectiveness of the major soft law vehicle ‘Corporate Social Responsibility’ (CSR). The fact that employees are working in unsafe working conditions does not mean Australia is breaching its human rights obligations. Australia is only required to take reasonably practicable steps to ensure human rights are realized. Phase 3 identifies four regulatory vehicles to determine whether they would assist Australia in discharging its human rights obligations. Phase 3 then analyses whether Australia could unilaterally introduce supply chain regulation to regulate domestic and extraterritorial supply chains. Phase 3 also analyses three public international law regulatory vehicles. This chapter considers the ability of the United Nations Global Compact, the ILO’s Better Factory Project and a bilateral agreement to improve the detection and enforcement of workers’ right to safety and health.

The reduced expression of the HADH2 protein causes X-linked mental retardation, choreoathetosis, and abnormal behavior

Recently, we defined a new syndromic form of X-linked mental retardation in a 4-generation family with a unique clinical phenotype characterized by mild mental retardation, choreoathetosis, and abnormal behavior (MRXS10). Linkage analysis in this family revealed a candidate region of 13.4 Mb between markers DXS1201 and DXS991 on Xp11; therefore, mutation analysis was performed by direct sequencing in most of the 135 annotated genes located in the region. The gene (HADH2) encoding L-3-hydroxyacyl-CoA dehydrogenase II displayed a sequence alteration (c.574 C-->A; p.R192R) in all patients and carrier females that was absent in unaffected male family members and could not be found in 2,500 control X chromosomes, including in those of 500 healthy males. The silent C-->A substitution is located in exon 5 and was shown by western blot to reduce the amount of HADH2 protein by 60%-70% in the patient. Quantitative in vivo and in vitro expression studies revealed a ratio of splicing transcript amounts different from those normally seen in controls. Apparently, the reduced expression of the wild-type fragment, which results in the decreased protein expression, rather than the increased amount of aberrant splicing fragments of the HADH2 gene, is pathogenic. Our data therefore strongly suggest that reduced expression of the HADH2 protein causes MRXS10, a phenotype different from that caused by 2-methyl-3-hydroxybutyryl-CoA dehydrogenase deficiency, which is a neurodegenerative disorder caused by missense mutations in this multifunctional protein.

Acute injuries in track and field athletes: A 3-year observational study at the Penn Relays Carnival with epidemiology and medical coverage implications

Background Few studies have examined acute injuries in track and field in both elite and sub-elite athletes. Purpose To observe the absolute and relative rates of injury in track and field athletes across a wide range of competition levels and ages during three years of the Penn Relays Carnival to assist with future medical coverage planning and injury prevention strategies. Study design: Descriptive epidemiology study. Methods Over a 3-year period all injuries treated by the medical staff were recorded on a standardised injury report form. Absolute injury rates (absolute number of injuries) and relative injury rates (number of injuries per 1000 participants) were determined and odds ratios (OR) of injury rates were calculated between sexes, competition levels and events. Injuries were also broken down into major or minor medical or orthopedic injuries. Results Throughout the study period 48,473 competing athletes participated in the Penn Relays Carnival, and 436 injuries were sustained. For medical coverage purposes, the relative rate of injury subtypes was greatest for minor orthopedic injuries (5.71 injuries per 1000 participants), followed by minor medical injuries (3.42 injuries per 1000 participants), major medical injuries (0.69 injuries per 1000 participants) and major orthopedic injuries (0.18 injuries per 1000 participants). College/elite level athletes displayed the lowest relative injury rate (7.99 injuries per 1000 participants), which was significantly less than high school (9.87 injuries per 1000 participants) and masters level athletes (16.33 injuries per 1000 participants). Males displayed a greater likelihood of suffering a minor orthopedic injury compared to females (OR = 1.36, 95% CI = 1.06 to 1.75; χ2 = 5.73, p = 0.017) but were less likely to sustain a major medical injury (OR = 0.33, 95% CI = 0.15 to 0.75; χ2 = 7.75, p = 0.005). Of the three most heavily participated in events, the 4 x 400m relay displayed the greatest relative injury rate (13.6 injuries per 1000 participants) compared to the 4 x 100 and 4 x 200m relay. Conclusions Medical coverage teams for future large scale track and field events need to plan for at least two major orthopedic and seven major medical injuries per 1000 participants. Male track and field athletes, particularly masters level male athletes, are at greater risk of injury compared to other genders and competition levels.