BRAKING AND PROPULSIVE IMPULSES ACROSS A RANGE OF RUNNING SPEEDS IN UNILATERAL TRANSFEMORAL AMPUTEES

Braking and propulsive ground reaction force impulses (GRIs) are mechanical parameters affecting the running performance. The purpose of this study was to determine the braking and propulsive GRIs across a range of speeds in unilateral transfemoral amputees. Ten unilateral transfemoral amputees ran on an instrumented treadmill at incremental speeds of 30%, 40%, 50%, 60%, and 70% of their maximum speed. At all given speeds, the braking GRI of affected limb was significantly smaller than unaffected limb; however, the propulsive GRIs were similar for both limbs. Consequently, the net anteroposterior GRI was positive in affected limb and negative in unaffected limb. These results suggest that the functional role of braking and propulsion is not the same between the limbs. Training for unilateral transfemoral amputees could focus on reducing the braking GRI of unaffected limb

Characterization of the role of the tumor marker Nup88 in mitosis

Nuclear pore complexes are massive multiprotein channels responsible for traffic between the nucleus and cytoplasm, and are composed of approximately 30 proteins, termed nucleoporins (Nup). Our recent studies indicated that the nucleoporins Rae1 and Tpr play critical roles in maintaining the spindle bipolarity during cell division. In the present study, we found that another nucleoporin, Nup88, was localized on the spindles together with Nup214 during mitosis. Nup88 expression is linked to the progression of carcinogenesis, Nup88 has been proposed as a tumor marker. Overexpression of Nup88 enhanced multinucleated cell formation. RNAi-mediated knockdown of Nup88 disrupted Nup214 expression and localization and caused multipolar spindle phenotypes. Our data indicate that proper expression of Nup88 is critical for preventing aneuploidy formation and tumorigenesis

RUNNING MECHANICS IN UNILATERAL TRANSFEMORAL AMPUTEES ACROSS A RANGE OF SPEEDS

Running-specific prostheses (RSP) allows individuals with lower extremity amputations to participate in running activities. The aim of this study was to investigate the average vertical ground reaction force (Favg), step frequency (Freqstep) and contact length (Lc) between intact and prosthetic limb across a range of running speeds. Nine unilateral transfemoral amputees with RSP performed running on instrumented treadmill at incremental speeds of 30, 40, 50, 60 and 70% of their maximum speed. We found that prosthetic limb generated smaller Favg than intact limb, and had similar Freqstep between limbs. However, prosthetic limb had longer Lc than intact limb at faster speeds. These results suggest that unilateral transfemoral amputees using RSP have asymmetrical running mechanics between limbs to adapt to the increasing running speed

LEG AND VERTICAL STIFFNESS OF TRANSFEMORAL AMPUTEES USING RUNNING-SPECIFIC PROSTHESES

Since running-specific prostheses (RSPs) emulate spring-like leg functions, human musculoskeletal system is often modelled as a spring-mass model. In the model, the leg (KM) and vertical stiffness (KM) is known to strongly influence running performance. The purpose of this study was to quantify the asymmetry in stiffness between the intact limbs and prosthetic limbs during sprinting. Eight sprinters with unilateral transfemoral amputation performed overground sprinting at maximum speed. & and Kw,t were calculated from vertical ground reaction force data in both the intact and prosthetic limbs. & was significantly greater in intact limbs than prosthetic limbs. Although there was no significant difference on Kvert, cohen's d of Kvert between legs was 1.28. Therefore KM might have potential significant difference

COMPARISON OF GROUND REACTION FORCES IN TWO RUNNING-SPECIFIC PROSTHESES (SPRINTER 1 E90 AND CHEETAH XTREME): A CASE STUDY

The purpose of this study was to describe the difference in ground reaction forces (GRF) between tvm different running-specific prostheses (RSPs) during maximal sprinting in a transfemoral amputee. One male sprinter performed maximal sprinting with two types of RSP (Sprinter 1E90 and Xtreme) on over 40 m runway with 7 force plates located halfway. Sprint velocity was found to be greater in the trials performed with Sprinter 1 E9O than with Xtreme. The peak VGRF, zero fore-aft shear and impulse of the anteriorposterior component of the GRF with PST limb differed among the two RSPs. These results suggest that the participant in this study would show the differences in variables influencing on the sprint velocity between two types of RSPs

Gene expression profiles of novel caprine placental prolactin-related proteins similar to bovine placental prolactin-related proteins

BACKGROUND: This study reports the identification of a full-length cDNA sequence for two novel caprine prolactin-related proteins (cPRP1 and cPRP6), and their localization and quantitative expression in the placenta. Caprine PRPs are compared with known bovine PRPs. We examined their evolution and role in the ruminant placenta. RESULTS: Full-length cPRP1 and cPRP6 cDNA were cloned with a 717- and 720- nucleotide open-reading frame corresponding to proteins of 238 and 239 amino acids. The cPRP1 predicted amino acid sequence shares a 72% homology with bovine PRP1 (bPRP1). The cPRP6 predicted amino acid sequence shares a 74% homology with bovine PRP6 (bPRP6). The two cPRPs as well as bPRPs were detected only in the placentome by RT-PCR. Analysis by in situ hybridization revealed the presence of both cPRPs mRNA in the trophoblast binucleate cells. These mRNA were quantified by real-time RT-PCR analysis of the placentome at 30, 50, 90 and 140 days of pregnancy. Both new cPRP genes were able to translate a mature protein in a mammalian cell-expression system. Western blotting established the molecular sizes of 33 kDa for cPRP1 with FLAG-tag and 45 kDa for cPRP6 with FLAG-tag. The sequence properties and localized expression of cPRP1 and cPRP6 were similar to those of bovine. However, their expression profiles differed from those in bovine placenta. Although this study demonstrated possible roles of PRPs in caprine placenta, PRPs may regulate binucleate-cell functions like those in bovine, but their crucial roles are still unclear. CONCLUSION: We have identified the novel PRPs in caprine placenta. Localization and quantitative expression of caprine PRPs were compared with bovine PRPs. The data indicate that PRP genes in caprine placenta have coordination functions for gestation, as they do in bovine. This is the first study of PRPs function in caprine placenta

JOINT MOMENTS OF UNILATERAL TRANSFEMORAL AMPUTEES USING RUNNING-SPECIFIC PROSTHESIS DURING SPRINTING

The aim of this study was to investigate the bilateral difference of the joint moments between an intact leg (INT) and a prosthetic leg (PST) in unilateral transfemoral amputees (TFAs) wearing running-specific prosthesis during sprinting. Eight sprinters with unilateral TFAs performed maximal sprinting on a 40-m runway with 7 force platforms located in between. Hip and knee joint extension and flexion moments during stance phase in INT were significantly greater than those of PST. However, ankle plantarflexion moment in PST was significantly greater than that of INT. Since kinetic asymmetry between legs is thought to be related with running-related injury, sprinter with unilateral TFAs may have a higher risk of musculoskeletal injury at hip and knee joints

A New Electrophysiological Method for the Diagnosis of Extraforaminal Stenosis at L5-S1

Study DesignA retrospective study.PurposeTo examine the effectiveness of using an electrodiagnostic technique as a new approach in the clinical diagnosis of extraforaminal stenosis at L5-S1.Overview of LiteratureWe introduced a new effective approach to the diagnosis of extraforaminal stenosis at the lumbosacral junction using the existing electrophysiological evaluation technique.MethodsA consecutive series of 124 patients with fifth lumbar radiculopathy were enrolled, comprising a group of 74 patients with spinal canal stenosis and a second group of 50 patients with extraforaminal stenosis at L5-S1. The technique involved inserting a pair of needle electrodes into the foraminal exit zone of the fifth lumbar spinal nerves, which were used to provide electrical stimulation. The compound muscle action potentials from each of the tibialis anterior muscles were recorded.ResultsThe distal motor latency (DML) of the potentials ranged from 11.2 to 24.6 milliseconds in patients with extraforaminal stenosis. In contrast, the DML in patients with spinal canal stenosis ranged from 10.0 to 17.2 milliseconds. After comparing the DML of each of the 2 groups and at the same time comparing the differences in DML between the affected and unaffected side of each patient, we concluded there were statistically significant differences (p<0.01) between the 2 groups. Using receiver operating characteristic curve analysis, the cutoff values were calculated to be 15.2 milliseconds and 1.1 milliseconds, respectively.ConclusionsThis approach using a means of DML measurement enables us to identify and localize lesions, which offers an advantage in diagnosing extraforaminal stenosis at L5-S1