Reproducibility and validity of video screen measurements of gait in children with spastic cerebral palsy

PURPOSE: To determine the reproducibility and validity of video screen measurement (VSM) of sagittal plane joint angles during gait. METHODS: 17 children with spastic cerebral palsy walked on a 10m walkway. Videos were recorded and 3d-instrumented gait analysis was performed. Two investigators measured six sagittal joint/segment angles (shank, ankle, knee, hip, pelvis, and trunk) using a custom-made software package. The intra- and interrater reproducibility were expressed by the intraclass correlation coefficient (ICC), standard error of measurements (SEM) and smallest detectable difference (SDD). The agreement between VSM and 3d joint angles was illustrated by Bland-Altman plots and limits of agreement (LoA). RESULTS: Regarding the intrarater reproducibility of VSM, the ICC ranged from 0.99 (shank) to 0.58 (trunk), the SEM from 0.81 degrees (shank) to 5.97 degrees (trunk) and the SDD from 1.80 degrees (shank) to 16.55 degrees (trunk). Regarding the interrater reproducibility, the ICC ranged from 0.99 (shank) to 0.48 (trunk), the SEM from 0.70 degrees (shank) to 6.78 degrees (trunk) and the SDD from 1.95 degrees (shank) to 18.8 degrees (trunk). The LoA between VSM and 3d data ranged from 0.4+/-13.4 degrees (knee extension stance) to 12.0+/-14.6 degrees (ankle dorsiflexion swing). CONCLUSION: When performed by the same observer, VSM mostly allows the detection of relevant changes after an intervention. However, VSM angles differ from 3d-IGA and do not reflect the real sagittal joint position, probably due to the additional movements in the other planes.

A sensitized RNA interference screen identifies a novel role for the PI3K p110γ isoform in medulloblastoma cell proliferation and chemoresistance

Medulloblastoma is the most common malignant brain tumor in children and is associated with a poor outcome. We were interested in gaining further insight into the potential of targeting the human kinome as a novel approach to sensitize medulloblastoma to chemotherapeutic agents. A library of small interfering RNA (siRNA) was used to downregulate the known human protein and lipid kinases in medulloblastoma cell lines. The analysis of cell proliferation, in the presence or absence of a low dose of cisplatin after siRNA transfection, identified new protein and lipid kinases involved in medulloblastoma chemoresistance. PLK1 (polo-like kinase 1) was identified as a kinase involved in proliferation in medulloblastoma cell lines. Moreover, a set of 6 genes comprising ATR, LYK5, MPP2, PIK3CG, PIK4CA, and WNK4 were identified as contributing to both cell proliferation and resistance to cisplatin treatment in medulloblastoma cells. An analysis of the expression of the 6 target genes in primary medulloblastoma tumor samples and cell lines revealed overexpression of LYK5 and PIK3CG. The results of the siRNA screen were validated by target inhibition with specific pharmacological inhibitors. A pharmacological inhibitor of p110γ (encoded by PIK3CG) impaired cell proliferation in medulloblastoma cell lines and sensitized the cells to cisplatin treatment. Together, our data show that the p110γ phosphoinositide 3-kinase isoform is a novel target for combinatorial therapies in medulloblastoma.

[Should we screen and treat subclinical hypothyroidism?]

Subclinical hypothyroidism, defined as an elevated thyroid stimulating hormone and normal thyroxine level, is common with aging, particularly after 65 years old. This condition is potentially associated with important consequences, such as cardiovascular diseases and cognitive disorders. So far, indications for screening and thyroxine replacement therapy are still controversial. In this review, we examine the data on those risks and the potential benefits of the treatment. We also present a large European randomized clinical trial that should clarify this controversy, in order to improve clinical care of patients with subclinical hypothyroidism and to give reliable data on maintaining good health among the elderly.

Using micropower impulse radar technology to screen for pneumothorax: an international bi-institutional study

Pneumothoraces (PTXs) are a common entity in thoracic trauma. Micropower impulse radar (MIR) has been able to detect PTXs in surgical patients. However, this technology has not been tested previously on trauma patients. The purpose of this study was to determine the sensitivity and specificity of MIR to detect clinically significant PTXs. We hypothesized that MIR technology can effectively screen trauma patients for clinically significant PTXs.

Visual vector inversion during memory antisaccades--a TMS study

In the memory antisaccade task, subjects are instructed to look at an imaginary point precisely at the opposite side of a peripheral visual stimulus presented short time previously. To perform this task accurately, the visual vector, i.e., the distance between a central fixation point and the peripheral stimulus, must be inverted from one visual hemifield to the other. Recent data in humans and monkeys suggest that the posterior parietal cortex (PPC) might be critically involved in the process of visual vector inversion. In the present study, we investigated the temporal dynamics of visual vector inversion in the human PPC by using transcranial magnetic stimulation (TMS). In six healthy subjects, single pulse TMS was applied over the right PPC during a memory antisaccade task at four different time intervals: 100 ms, 217 ms, 333 ms, or 450 ms after target onset. The results indicate that for rightward antisaccades, i.e., when the visual target was presented in the left screen-half, TMS had a significant effect on saccade gain when applied 100 ms after target onset, but not later. For leftward antisaccades, i.e., when the visual target was presented in the right screen-half, a significant TMS effect on gain was found for the 333 ms and 450 ms conditions, but not for the earlier ones. This double dissociation of saccade gain suggests that the initial process of vector inversion can be disrupted 100 ms after onset of the visual stimulus and that TMS interfered with motor saccade planning based on an inversed vector signal at 333 ms and 450 ms after stimulus onset.

Multiphase Screen Development

This honors thesis research project was the study and development of a compact separation device for the oil and gas industry involving a multiphase cylindrical screen filter. Cylindrical screens can be used for solids removal in multiphase flow in upstream oil and gas applications. This study focused on cylindrical wire-wrap screen test unit design and performance characterization to determine volumetric flow rate and pressure drop correlations. The project goals were met with research, test unit design, CFD modeling, calculations, and physical testing. The comprehensive testing will take place during the summer of 2013 and is planned to consist of building the designed flowloop and housing and using high capacity pumps to achieve higher flow rates. Multiphase testing will be performed with water, air, and sand particles and flow and pressure effects will be evaluated for solids filtering over time.

Prostate cancer: to screen or not to screen?

Unfortunately, interim analyses of the long-awaited ERSPC and PLCO trial data have generated conflicting conclusions. Here, two European authors speculate as to the reasons underlying this contradiction, while highlighting clinically relevant points that are supported by both studies. Particular attention is paid to the potential consequences of overdiagnosis and overtreatment.