Scapholunate ligament injuries: an instructional review for the FRCS examination.

An instructional review of the anatomy, investigation, and management of scapholunate ligament injuries. Aimed at the knowledge level required for the trauma and orthopaedic FRCS examination.

Profiling of myristoylation in Toxoplasma gondii reveals an N-myristoylated protein important for host cell penetration.

N-myristoylation is a ubiquitous class of protein lipidation across eukaryotes and N-myristoyl transferase (NMT) has been proposed as an attractive drug target in several pathogens. Myristoylation often primes for subsequent palmitoylation and stable membrane attachment, however, growing evidence suggests additional regulatory roles for myristoylation on proteins. Here we describe the myristoylated proteome of Toxoplasma gondii using chemoproteomic methods and show that a small-molecule NMT inhibitor developed against related Plasmodium spp. is also functional in Toxoplasma. We identify myristoylation on a transmembrane protein, the microneme protein 7 (MIC7), which enters the secretory pathway in an unconventional fashion with the myristoylated N-terminus facing the lumen of the micronemes. MIC7 and its myristoylation play a crucial role in the initial steps of invasion, likely during the interaction with and penetration of the host cell. Myristoylation of secreted eukaryotic proteins represents a substantial expansion of the functional repertoire of this co-translational modification.

A microscopic parasite known as Toxoplasma gondii infects around 30% of the human population. Most infections remain asymptomatic, but in people with a compromised immune system, developing fetuses and people infected with particular virulent strains of the parasite, infection can be fatal. T. gondii is closely related to other parasites that also infect humans, including the one that causes malaria. These parasites have complex lifecycles that involve successive rounds of invading the cells of their hosts, growing and then exiting these cells. Signaling proteins found at specific locations within parasite cells regulate the ability of the parasites to interact with and invade host cells. Sometimes these signaling proteins are attached to membranes using lipid anchors, for example through a molecule called myristic acid. An enzyme called NMT can attach myristic acid to one end of its target proteins. The myristic acid tag can influence the ability of target proteins to bind to other proteins, or to membranes. Previous studies have found that drugs that inhibit the NMT enzyme prevent the malaria parasite from successfully invading and growing inside host cells. The NMT enzyme from T. gondii is very similar to that of the malaria parasite. Broncel et al. have shown that the drug developed against P. falciparum also inhibits the ability of T. gondii to grow. These findings suggest that drugs against the NMT enzyme may be useful to treat diseases caused by T. gondii and other closely-related parasites. Broncel et al. also identified 65 proteins in T. gondii that contain a myristic acid tag using an approach called proteomics. One of the unexpected 'myristoylated' proteins identified in the experiments is known as MIC7. This protein was found to be transported onto the surface of T. gondii parasites and is required in its myristoylated form for the parasite to successfully invade host cells. This was surprising as myristoylated proteins are generally thought to not enter the pathway that brings proteins to the outside of cell. These findings suggest that myristic acid on proteins that are secreted can facilitate interactions between cells, maybe by inserting the myristic acid into the cell membrane.

Differential requirements for cyclase-associated protein (CAP) in actin-dependent processes of Toxoplasma gondii.

Toxoplasma gondii contains a limited subset of actin binding proteins. Here we show that the putative actin regulator cyclase-associated protein (CAP) is present in two different isoforms and its deletion leads to significant defects in some but not all actin dependent processes. We observe defects in cell-cell communication, daughter cell orientation and the juxtanuclear accumulation of actin, but only modest defects in synchronicity of division and no defect in the replication of the apicoplast. 3D electron microscopy reveals that loss of CAP results in a defect in formation of a normal central residual body, but parasites remain connected within the vacuole. This dissociates synchronicity of division and parasite rosetting and reveals that establishment and maintenance of the residual body may be more complex than previously thought. These results highlight the different spatial requirements for F-actin regulation in Toxoplasma which appear to be achieved by partially overlapping functions of actin regulators.

Analyzing Moment Arm Profiles in a Full-Muscle Rat Hindlimb Model.

Understanding the kinematics of a hindlimb model is a fundamental aspect of modeling coordinated locomotion. This work describes the development process of a rat hindlimb model that contains a complete muscular system and incorporates physiological walking data to examine realistic muscle movements during a step cycle. Moment arm profiles for selected muscles are analyzed and presented as the first steps to calculating torque generation at hindlimb joints. A technique for calculating muscle moment arms from muscle attachment points in a three-dimensional (3D) space has been established. This model accounts for the configuration of adjacent joints, a critical aspect of biarticular moment arm analysis that must be considered when calculating joint torque. Moment arm profiles from isolated muscle motions are compared to two existing models. The dependence of biarticular muscle's moment arms on the configuration of the adjacent joint is a critical aspect of moment arm analysis that must be considered when calculating joint torque. The variability in moment arm profiles suggests changes in muscle function during a step.

Efficacy of an 8-Week Concurrent Strength and Endurance Training program on Hand Cycling Performance.

Nevin, JP, Smith, P, Waldron, M, Patterson, S, Price, M, Hunt, A, and Blagrove, R. Efficacy of an 8-week concurrent strength and endurance training program on hand cycling performance. J Strength Cond Res 32(7): 1861-1868, 2018-The aim of this study was to investigate the effects of an 8-week concurrent strength and endurance training program in comparison with endurance training only on several key determinants of hand cycling performance. Five H4 and 5 H3 classified hand cyclists with at least 1 year's hand cycling training history consented to participate in the study. Subjects underwent a battery of tests to establish body mass, body composition, V[Combining Dot Above]O2peak, maximum aerobic power, gross mechanical efficiency (GME), maximal upper-body strength, and 30-km time-trial performance. Subjects were matched into pairs based on 30-km time-trial performance and randomly allocated to either a concurrent strength and endurance or endurance training only, intervention group. After an 8-week training program based on a conjugated block periodization model, subjects completed a second battery of tests. A mixed model, 2-way analysis of variance revealed no significant changes between groups. However, the calculation of effect sizes (ESs) revealed that both groups demonstrated a positive improvement in most physiological and performance measures with subjects in the concurrent group demonstrating a greater magnitude of improvement in body composition (ES -0.80 vs. -0.22), maximal aerobic power (ES 0.97 vs. 0.28), GME (ES 0.87 vs. 0.63), bench press 1 repetition maximum (1RM) (ES 0.53 vs. 0.33), seated row 1RM (ES 1.42 vs. 0.43), and 30-km time-trial performance (ES -0.66 vs. -0.30). In comparison with endurance training only, an 8-week concurrent training intervention based on a conjugated block periodization model seems to be a more effective training regime for improving the performance capabilities of hand cyclists.

The potential for dispersant use as a maritime oil spill response measure in German waters.

In case of an oil spill, dispersant application represents a response option, which enhances the natural dispersion of oil and thus reduces coating of seabirds and coastal areas. However, as oil is transferred to the water phase, a trade-off of potential harmful effects shifted to other compartments must be performed. This paper summarizes the results of a workshop on the current knowledge on risks and benefits of the use of dispersants with respect to specific conditions encountered at the German sea areas. The German North Sea coast is a sensitive ecosystem characterised by tidal flats, barrier islands and salt marshes. Many prerequisites for a potential integration of dispersants as spill response option are available in Germany, including sensitivity maps and tools for drift modelling of dispersed and undispersed oil. However, open scientific questions remain concerning the persistence of dispersed oil trapped in the sediments and potential health effects.

Effects of tea consumption on renal function in a metropolitan Chinese population: the Guangzhou biobank cohort study.

OBJECTIVE: Green tea consumption has been associated with many prophylactic health benefits. This study examined for the first time associations between tea consumption and renal function in a Chinese population. DESIGN AND METHODS: Cross-sectional baseline data including demographics, and lifestyle and weekly consumption of green, black, and oolong tea were analyzed from 12,428 ambulatory subjects aged 50 to 85 years (67.3% female) that were randomly selected from the membership list of a community social and welfare association in Guangzhou, China. INTERVENTION: Associations between tea consumption and renal function were assessed using regression analyses to adjust for potential confounding factors. MAIN OUTCOME MEASURE: Renal function was assessed using the estimated glomerular filtration rate (eGFR) and in a subcohort of 1,910 participants using a spot urinary albumin-to-creatinine ratio. RESULTS: Six thousand eight hundred and seventy-two participants drank at least 1 type of tea. Oolong tea consumption was negatively associated with eGFR (ß-coefficient -0.019, P = .025), but in a gender-stratified analysis this was not the case. In men, black tea was positively associated with eGFR (ß-coefficient 0.037, P = .013), but not in women (ß-coefficient -0.002, P = .856). Otherwise, no statistically significant consistent associations between the measures of renal function and consumption of green tea, black tea, or oolong tea individually or total tea consumption were identified. CONCLUSION: Overall there was no clear evidence to suggest any consistent association between renal function and tea consumption in this large population-based study of older Chinese individuals.