Sliding and pressure evaluation on conventional and V-shaped seats of reclining wheelchairs for stroke patients with flaccid hemiplegia: a crossover trial

<p>Abstract</p> <p>Background</p> <p>Reclining wheelchairs are commonly used to transport elderly stroke patients in Taiwan. However, there is concern that the patient's body in the wheelchair often slides forward when they return to a seated position, increasing the sitting pressure. Therefore, a novel reclining wheelchair with an ergonomic "V-Seat" was designed to prevent forward sliding and pressure sores. The use of these reclining chairs by stroke patients has not yet been studied. Thus, we investigated the effects of V-shaped and conventional seats in reclining wheelchairs on the extent of forward sliding and on the sitting pressure of stroke patients with flaccid hemiplegia and of able-bodied elders.</p> <p>Methods</p> <p>We recruited 13 able-bodied elders and 11 stroke patients with flaccid hemiplegia and performed 5 reclining cycles in both types of wheelchair. The amount of sliding along the backrest (BS) plane and the seat (SS) plane, the mean sitting pressure (MP), and the sacral peak pressure (SPP) of the subjects were recorded. We used the Wilcoxon signed-rank test to compare the BS, SS, MP, and SPP in wheelchairs with conventional and V-shaped seats, and we used the Wilcoxon rank sum test to compare the differences in BS and SS between stroke patients and able-bodied elders in both types of reclining wheelchair.</p> <p>Results</p> <p>The BS, SS, and SPP of stroke patients were significantly lower in the wheelchairs with V-shaped seats than in conventional wheelchairs in most comparisons; however, the BS of able-bodied elders was higher in V-shaped seats than in conventional seats. The SS and SPP of stroke patients were significantly higher than those of able-bodied elders in both types of reclining wheelchair, and the BS of stroke patients was significantly higher than that of able-bodied elders only in conventional reclining wheelchairs.</p> <p>Conclusions</p> <p>The use of V-shaped seats in reclining wheelchairs can help reduce the forward sliding and sacral peak pressure of stroke patients with flaccid hemiplegia. The back displacement of able-bodied subjects when using both conventional and V-shape seats in reclining positions differs from the back displacement of stroke patients with flaccid hemiplegia when using such seats. These results are of paramount value and should be considered when prescribing the use of reclining wheelchairs to subjects with flaccid hemiplegia.</p

VI-Band Follow-Up Observations of Ultra-Long-Period Cepheid Candidates in M31

The ultra-long period Cepheids (ULPCs) are classical Cepheids with pulsation periods exceeding $\approx 80$ days. The intrinsic brightness of ULPCs are ~1 to ~3 mag brighter than their shorter period counterparts. This makes them attractive in future distance scale work to derive distances beyond the limit set by the shorter period Cepheids. We have initiated a program to search for ULPCs in M31, using the single-band data taken from the Palomar Transient Factory, and identified eight possible candidates. In this work, we presented the VI-band follow-up observations of these eight candidates. Based on our VI-band light curves of these candidates and their locations in the color-magnitude diagram and the Period-Wesenheit diagram, we verify two candidates as being truly ULPCs. The six other candidates are most likely other kinds of long-period variables. With the two confirmed M31 ULPCs, we tested the applicability of ULPCs in distance scale work by deriving the distance modulus of M31. It was found to be $\mu_{M31,ULPC}=24.30\pm0.76$ mag. The large error in the derived distance modulus, together with the large intrinsic dispersion of the Period-Wesenheit (PW) relation and the small number of ULPCs in a given host galaxy, means that the question of the suitability of ULPCs as standard candles is still open. Further work is needed to enlarge the sample of calibrating ULPCs and reduce the intrinsic dispersion of the PW relation before re-considering ULPCs as suitable distance indicators.Comment: 13 pages, with 14 Figures and 4 Tables (one online table). AJ accepte

POINeT: protein interactome with sub-network analysis and hub prioritization

<p>Abstract</p> <p>Background</p> <p>Protein-protein interactions (PPIs) are critical to every aspect of biological processes. Expansion of all PPIs from a set of given queries often results in a complex PPI network lacking spatiotemporal consideration. Moreover, the reliability of available PPI resources, which consist of low- and high-throughput data, for network construction remains a significant challenge. Even though a number of software tools are available to facilitate PPI network analysis, an integrated tool is crucial to alleviate the burden on querying across multiple web servers and software tools.</p> <p>Results</p> <p>We have constructed an integrated web service, POINeT, to simplify the process of PPI searching, analysis, and visualization. POINeT merges PPI and tissue-specific expression data from multiple resources. The tissue-specific PPIs and the numbers of research papers supporting the PPIs can be filtered with user-adjustable threshold values and are dynamically updated in the viewer. The network constructed in POINeT can be readily analyzed with, for example, the built-in centrality calculation module and an integrated network viewer. Nodes in global networks can also be ranked and filtered using various network analysis formulas, i.e., centralities. To prioritize the sub-network, we developed a ranking filtered method (S3) to uncover potential novel mediators in the midbody network. Several examples are provided to illustrate the functionality of POINeT. The network constructed from four schizophrenia risk markers suggests that EXOC4 might be a novel marker for this disease. Finally, a liver-specific PPI network has been filtered with adult and fetal liver expression profiles.</p> <p>Conclusion</p> <p>The functionalities provided by POINeT are highly improved compared to previous version of POINT. POINeT enables the identification and ranking of potential novel genes involved in a sub-network. Combining with tissue-specific gene expression profiles, PPIs specific to selected tissues can be revealed. The straightforward interface of POINeT makes PPI search and analysis just a few clicks away. The modular design permits further functional enhancement without hampering the simplicity. POINeT is available at <url>http://poinet.bioinformatics.tw/</url>.</p

Autophosphorylated CaMKIIα Acts as a Scaffold to Recruit Proteasomes to Dendritic Spines

The molecular mechanisms regulating the ubiquitin proteasome system (UPS) at synapses are poorly understood. We report that CaMKIIα—an abundant postsynaptic protein kinase—mediates the activity-dependent recruitment of proteasomes to dendritic spines in hippocampal neurons. CaMKIIα is biochemically associated with proteasomes in the brain. CaMKIIα translocation to synapses is required for activity-induced proteasome accumulation in spines, and is sufficient to redistribute proteasomes to postsynaptic sites. CaMKIIα autophosphorylation enhances its binding to proteasomes and promotes proteasome recruitment to spines. In addition to this structural role, CaMKIIα stimulates proteasome activity by phosphorylating proteasome subunit Rpt6 on Serine 120. However, CaMKIIα translocation, but not its kinase activity, is required for activity-dependent degradation of polyubiquitinated proteins in spines. Our findings reveal a scaffolding role of postsynaptic CaMKIIα in activity-dependent proteasome redistribution, which is commensurate with the great abundance of CaMKIIα in synapses.Howard Hughes Medical Institute (Investigator

The reinforcing influence of recommendations on global diversification

Recommender systems are promising ways to filter the overabundant information in modern society. Their algorithms help individuals to explore decent items, but it is unclear how they allocate popularity among items. In this paper, we simulate successive recommendations and measure their influence on the dispersion of item popularity by Gini coefficient. Our result indicates that local diffusion and collaborative filtering reinforce the popularity of hot items, widening the popularity dispersion. On the other hand, the heat conduction algorithm increases the popularity of the niche items and generates smaller dispersion of item popularity. Simulations are compared to mean-field predictions. Our results suggest that recommender systems have reinforcing influence on global diversification.Comment: 6 pages, 6 figure

WebPARE: web-computing for inferring genetic or transcriptional interactions

Summary: Inferring genetic or transcriptional interactions, when done successfully, may provide insights into biological processes or biochemical pathways of interest. Unfortunately, most computational algorithms require a certain level of programming expertise. To provide a simple web interface for users to infer interactions from time course gene expression data, we present WebPARE, which is based on the pattern recognition algorithm (PARE). For expression data, in which each type of interaction (e.g. activator target) and the corresponding paired gene expression pattern are significantly associated, PARE uses a non-linear score to classify gene pairs of interest into a few subclasses of various time lags. In each subclass, PARE learns the parameters in the decision score using known interactions from biological experiments or published literature. Subsequently, the trained algorithm predicts interactions of a similar nature. Previously, PARE was shown to infer two sets of interactions in yeast successfully. Moreover, several predicted genetic interactions coincided with existing pathways; this indicates the potential of PARE in predicting partial pathway components. Given a list of gene pairs or genes of interest and expression data, WebPARE invokes PARE and outputs predicted interactions and their networks in directed graphs

Ellagic Acid, the Active Compound of Phyllanthus urinaria, Exerts In Vivo Anti-Angiogenic Effect and Inhibits MMP-2 Activity

This study aimed to assess the potential anti-angiogenic mechanism of Phyllanthus urinaria (P. urinaria) and characterize the major compound in P. urinaria that exerts anti-angiogenic effect. The water extract of P. urinaria and Ellagic Acid were used to evaluate the anti-angiogenic effect in chorioallantoic membrane (CAM) in chicken embryo and human vascular endothelial cells (HUVECs). The matrix metalloproteinase-2 (MMP-2) activity was determined by gelatin zymography. The mRNA expressions of MMP-2, MMP-14 and tissue inhibitor of metalloproteinase-2 (TIMP-2) were analyzed by reverse transcription polymerase chain reaction (RT-PCR). Level of MMP-2 proteins in conditioned medium or cytosol was determined by western blot analysis. We confirmed that P. urinaria's in vivo anti-angiogenic effect was associated with a reduction in MMP-2 activity. Ellagic acid, one of the major polyphenolic components as identified in P. urinaria by high performance liquid chromatography mass spectrometry (HPLC/MS), exhibited the same anti-angiogenic effect in vivo. Both P. urinaria and Ellagic Acid inhibited MMP-2 activity in HUVECs with unchanged mRNA level. The mRNA expression levels of MMP-14 and TIMP-2 were not altered either. Results from comparing the change of MMP-2 protein levels in conditioned medium and cytosol of HUVECs after the P. urinaria or Ellagic Acid treatment revealed an inhibitory effect on the secretion of MMP-2 protein. This study concluded that Ellagic Acid is the active compound in P. urinaria to exhibit anti-angiogenic activity and to inhibit the secretion of MMP-2 protein from HUVECs

Identification of overexpressed cytokines as serum biomarkers of hepatitis C virus-induced liver fibrosis using bead-based flexible multiple analyte profiling

Hepatic inflammation is the stimulator to activate hepatic stellate cells (HSCs) and triggers fibrogenesis. Cytokines are produced during liver inflammation and maybe considered as liver fibrosis biomarker. The aim of this study was to investigate whether cytokines can be used as reliable biomarkers of liver fibrosis using flexible multi-analyte profiling (xMAP). A total of 61 chronic hepatitis C patients with different severity of liver fibrosis were enrolled. Liver biopsy was used as standard to assess the severity of fibrosis according to METAVIR classification. Afterward, 15 samples from healthy controls were analyzed and totally 50 cytokines were screened using flexible multi-analyte profiling to discover differential biomarkers. Finally, levels of protein expressions of individual stages of liver fibrosis were measured. In histological examination, the necroinflammatory score (histology activity index, HAI) was increased from F1 to F4 stage in hepatitis C virus (HCV) infected patients, indicating that inflammation was accompanied with the progression of liver fibrosis. Using flexible multi-analyte profiling, four serum cytokines, including IFN-α2 (p=0.023), GRO-α (p=0.013), SCF (p=0.047) and SDF-1α p=0.024), were identified under antibody specific recognition and elevated with HAI score. This study reveals the relationship between cytokines and liver fibrosis, and demonstrated that IFN-α2, GRO-α, SCF and SDF-1 α may be used as biomarkers to predict liver fibrosis. The overexpressed cytokines may play a role in the progression of liver fibrosis and deserves further investigation.Keywords: Cytokine, flexible multi-analyte profiling, hepatitis C virus, liver fibrosisAfrican Journal of Biotechnology Vol. 11(29), pp. 7535-7541, 29 April, 201