Development of a System to Monitor Laryngeal Movement during Swallowing Using a Bend Sensor

Background

Swallowing dysfunction (also known as dysphagia), which results in a deterioration of nutritional intake, slows rehabilitation and causes aspiration pneumonia, is very common following neurological impairments. Although videofluorographic (VF) examination is widely used for detecting aspiration, an objective and non-invasive method for assessing swallowing function has yet to be established because of a lack of adequate devices and protocols. In this paper, a bend sensor whose resistance is altered by bending was introduced to monitor swallowing-related laryngeal movement.

Methods

Six healthy male volunteers were recruited in the present study. Specific time points on the signal waveform produced by the bend sensor were defined to describe laryngeal movement by differential analysis. Additionally, the physiological significance of the obtained waveform was confirmed by analyzing the sequential correlations between the signal waveform from the bend sensor and hyoid bone kinetics simultaneously recorded by VF.

Results

Seven time points were successfully defined on the signal waveform to reference laryngeal movement. Each time point was well correlated with certain VF events, with evidence of no significant time lags, and there were positive correlations between waveform time points and matched VF events. Furthermore, obvious similarities were noticed between the duration of each phase on the signal waveform and the duration of the matched hyoid bone activity.

Conclusions

The present monitoring system using a bend sensor might be useful for observing the temporal aspects of laryngeal movement during swallowing, and it was well coordinated with hyoid bone movement.     

GsSnRK1 interplays with transcription factor GsERF7 from wild soybean to regulate soybean stress resistance

Although the function and regulation of SnRK1 have been studied in various plants, its molecular mechanisms in response to abiotic stresses are still elusive. In this work, we identified an AP2/ERF domain-containing protein (designated GsERF7) interacting with GsSnRK1 from a wild soybean cDNA library. GsERF7 gene expressed dominantly in wild soybean roots and was responsive to ethylene, salt, and alkaline. GsERF7 bound GCC cis-acting element and could be phosphorylated on S36 by GsSnRK1. GsERF7 phosphorylation facilitated its translocation from cytoplasm to nucleus and enhanced its transactivation activity. When coexpressed in the hairy roots of soybean seedlings, GsSnRK1(wt) and GsERF7(wt) promoted plants to generate higher tolerance to salt and alkaline stresses than their mutated species, suggesting that GsSnRK1 may function as a biochemical and genetic upstream kinase of GsERF7 to regulate plant adaptation to environmental stresses. Furthermore, the altered expression patterns of representative abiotic stress-responsive and hormone-synthetic genes were determined in transgenic soybean hairy roots after stress treatments. These results will aid our understanding of molecular mechanism of how SnRK1 kinase plays a cardinal role in regulating plant stress resistances through activating the biological functions of downstream factors.     

A Novel Domain of Amino-Nogo-A Protects HT22 Cells Exposed to Oxygen Glucose Deprivation by Inhibiting NADPH Oxidase Activity

This study aimed to investigate the protective effect of the M9 region (residues 290–562) of amino-Nogo-A fused to the human immunodeficiency virus trans-activator TAT in an in vitro model of ischemia–reperfusion induced by oxygen–glucose deprivation (OGD) in HT22 hippocampal neurons, and to investigate the role of NADPH oxidase in this protection. Transduction of TAT-M9 was analyzed by immunofluorescence staining and western blot. The biologic activity of TAT-M9 was assessed by its effects against OGD-induced HT22 cell damage, compared with a mutant M9 fusion protein or vehicle. Cellular viability and lactate dehydrogenase (LDH) release were assessed. Neuronal apoptosis was evaluated by flow cytometry. The Bax/Bcl-2 ratio was determined by western blotting. Reactive oxygen species (ROS) levels and NADPH oxidase activity were also measured in the presence or absence of an inhibitor or activator of NADPH oxidase. Our results confirmed the delivery of the protein into HT22 cells by immunofluorescence and western blot. Addition of 0.4 μmol/L TAT-M9 to the culture medium effectively improved neuronal cell viability and reduced LDH release induced by OGD. The fusion protein also protected HT22 cells from apoptosis, suppressed overexpression of Bax, and inhibited the reduction in Bcl-2 expression. Furthermore, TAT-M9, as well as apocynin, decreased NADPH oxidase activity and ROS content. The protective effects of the TAT-M9 were reversed by TBCA, an agonist of NADPH oxidase. In conclusion, TAT-M9 could be successfully transduced into HT22 cells, and protected HT22 cells against OGD damage by inhibiting NADPH oxidase-mediated oxidative stress. These findings suggest that the TAT-M9 protein may be an efficient therapeutic agent for neuroprotection.     

Effect of mesenchymal stem cells on inhibiting airway remodeling and airway inflammation in chronic asthma

Previous studies proved that bone marrow‐derived mesenchymal stem cells (BMSCs) could improve a variety of immune‐mediated disease by its immunomodulatory properties. In this study, we investigated the effect on airway remodeling and airway inflammation by administrating BMSCs in chronic asthmatic mice. Forty‐eight female BALB/c mice were randomly distributed into PBS group, BMSCs treatment group, BMSCs control group, and asthmatic group. The levels of cytokine and immunoglobulin in serum and bronchoalveolar lavage fluid were detected by enzyme‐linked immunosorbent assay. The number of CD4⁺CD25⁺regulatory T cells and morphometric analysis was determined by flow cytometry, hematoxylin‐eosin, immunofluorescence staining, periodic‐acid Schiff, and masson staining, respectively. We found that airway remodeling and airway inflammation were evident in asthmatic mice. Moreover, low level of IL‐12 and high levels of IL‐13, IL‐4, OVA‐specific IgG1, IgE, and IgG2a and the fewer number of CD4⁺CD25⁺regulatory T cells were present in asthmatic group. However, transplantation of BMSCs significantly decreased airway inflammation and airway remodeling and level of IL‐4, OVA‐specific IgE, and OVA‐specific IgG1, but elevated level of IL‐12 and the number of CD4 + CD25 + regulatory T cells in asthma (P < 0.05). However, BMSCs did not contribute to lung regeneration and had no significant effect on levels of IL‐10, IFN‐Y, and IL‐13. In our study, BMSCs engraftment prohibited airway inflammation and airway remodeling in chronic asthmatic group. The beneficial effect of BMSCs might involved the modulation imbalance cytokine toward a new balance Th1–Th2 profiles and up‐regulation of protective CD4 + CD25 + regulatory T cells in asthma, but not contribution to lung regeneration. J. Cell. Biochem. 114: 1595–1605, 2013. © 2013 Wiley Periodicals, Inc.     

Vascular Occlusions in Grapevines with Pierce’s Disease Make Disease Symptom Development Worse

Vascular occlusions are common structural modifications made by many plant species in response to pathogen infection. However, the functional role(s) of occlusions in host plant disease resistance/susceptibility remains controversial. This study focuses on vascular occlusions that form in stem secondary xylem of grapevines (Vitis vinifera) infected with Pierce’s disease (PD) and the impact of occlusions on the hosts’ water transport and the systemic spread of the causal bacterium Xylella fastidiosa in infected vines. Tyloses are the predominant type of occlusion that forms in grapevine genotypes with differing PD resistances. Tyloses form throughout PD-susceptible grapevines with over 60% of the vessels in transverse sections of all examined internodes becoming fully blocked. By contrast, tylose development was mainly limited to a few internodes close to the point of inoculation in PD-resistant grapevines, impacting only 20% or less of the vessels. The extensive vessel blockage in PD-susceptible grapevines was correlated to a greater than 90% decrease in stem hydraulic conductivity, compared with an approximately 30% reduction in the stems of PD-resistant vines. Despite the systemic spread of X. fastidiosa in PD-susceptible grapevines, the pathogen colonized only 15% or less of the vessels in any internode and occurred in relatively small numbers, amounts much too small to directly block the vessels. Therefore, we concluded that the extensive formation of vascular occlusions in PD-susceptible grapevines does not prevent the pathogen’s systemic spread in them, but may significantly suppress the vines’ water conduction, contributing to PD symptom development and the vines’ eventual death.Pierce’s disease (PD) of grapevines (Vitis vinifera), currently jeopardizing the wine and table grape industries in the southern United States and California, as well as in many other countries, is a vascular disease caused by the xylem-limited bacterium Xylella fastidiosa (Hopkins, 1989; Varela et al., 2001). The pathogen is transmitted mostly via xylem sap-feeding sharpshooters (e.g. Homalodisca vitripennis; Redak et al., 2004) and inhabits, proliferates, and spreads within the vessel system of a host grapevine (Fry and Milholland, 1990a; Hill and Purcell, 1995). PD symptom development in grapevines depends on the interactions between the pathogen and the host vine’s xylem tissue, through which the pathogen may achieve its systemic spread (Purcell and Hopkins, 1996; Krivanek and Walker, 2005; Pérez-Donoso et al., 2010; Sun et al., 2011). Since the path for this spread is the host’s xylem system, xylem tissue and its vessels have become the major focus for studying potential X. fastidiosa-host vine interactions at the cellular or tissue levels (Fry and Milholland, 1990b; Stevenson et al., 2004a; Sun et al., 2006, 2007; Thorne et al., 2006).One major issue related to this host-pathogen interaction is the relationship of a vine’s xylem anatomy to the X. fastidiosa population’s spread. Sun et al. (2006) did a detailed anatomical analysis of the stem secondary xylem, especially the vessel system. Stevenson et al. (2004b) described xylem connection patterns between a stem and the attached leaves. Other studies reported the presence of open continuous vessels connecting stems and leaves, which represent conduits that might facilitate the pathogen’s stem-to-leaf movement (Thorne et al., 2006; Chatelet et al., 2006, 2011). Chatelet et al. (2011) also suggested that vessel size and ray density were the two xylem features that were most relevant to the restriction of X. fastidiosa’s movement. These studies indicate the importance of understanding the grapevine’s xylem anatomy in order to characterize the grapevine host’s susceptibility or resistance to PD.Another focus of PD-related xylem studies is the tylose, a developmental modification that has important impacts on a vessel’s role in water transport and, potentially, its availability as a path for X. fastidiosa’s systemic spread through a vine. Tyloses are outgrowths into a vessel lumen from living parenchyma cells that are adjacent to the vessel and can transfer solutes into the transpiration stream via vessel-parenchyma (V-P) pit pairs (Esau, 1977). Tylose development involves the expansion of the portions of the parenchyma cell’s wall that are shared with the neighboring vessels, specifically the so-called pit membranes (PMs). Intensive tylose development may eventually block the affected vessel (Sun et al., 2006). Since tyloses occur in the vessel system of PD-infected grapevines (Esau, 1948; Mollenhauer and Hopkins, 1976; Stevenson et al., 2004a; Krivanek et al., 2005) that is also the avenue of X. fastidiosa’s spread and water transport, a great deal of effort has been made to understand tyloses and their possible relations to grapevine PD as well as to diseases caused by other vascular system-localized pathogens. One major aspect is to clarify the process of tylose development itself, in which an open vessel may be gradually sealed (Sun et al., 2006, 2008). Our investigations of the initiation of tylose formation in grapevines have identified ethylene as an important factor (Pérez-Donoso et al., 2007; Sun et al., 2007). In terms of the relationship of tyloses to grapevine PD, studies have so far led to several controversial viewpoints that are discussed below (Mollenhauer and Hopkins, 1976; Fry and Milholland, 1990b; Stevenson et al., 2004a; Krivanek et al., 2005). However, more convincing evidence is still needed to support any of them.Another issue potentially relevant to PD symptom development is the possibility that X. fastidiosa cells and/or their secretions contribute to the blockage of water transport in host vines. The bacteria secrete an exopolysaccharide (Roper et al., 2007a) that contributes to the formation of cellular aggregates. Accumulations of X. fastidiosa cells embedded in an exopolysaccharide matrix (occasionally identified as biofilms, gums, or gels) have been reported in PD-infected grapevines (Mollenhauer and Hopkins, 1974; Fry and Milholland, 1990a; Newman et al., 2003; Stevenson et al., 2004b). However, a more detailed investigation is still needed to clarify if and to what extent these aggregates affect water transport in infected grapevines.The xylem tissue in which X. fastidiosa spreads can be classified as primary xylem or secondary xylem, being derived from procambium or vascular cambium, respectively. Primary xylem is located in and responsible for material transport and structural support in young organs (i.e. leaves, young stems, and roots), while secondary xylem is the conductive and supportive tissue in more mature stems and roots (Esau, 1977). It should be noted that most of the earlier experimental results have been based on examinations of leaves (petioles or veins) or young stems of grapevines, which contain mostly primary xylem with little or no secondary xylem. However, X. fastidiosa’s systemic spread generally occurs after introduction during the insect vector’s feeding from an internode of one shoot. The pathogen then moves upward along that shoot and also downward toward the shoot base. The downward movement allows the bacteria to enter the vine’s other shoots via the shared trunk and then move upward (Stevenson et al., 2004a; Sun et al., 2011). These upward and downward bacterial movements occur through stems that contain significant amounts of secondary xylem but relatively dysfunctional primary xylem. Secondary and primary xylem show some major differences in the structure and arrangement of their cell components (Esau, 1977). In terms of the vessel system that is the path of X. fastidiosa’s spread, the secondary xylem has a large number of much bigger vessels with scalariform (ladder-like) PMs (and pit pairs) as the sole intervessel (I-V) PM type, compared with the primary xylem, which contains only a limited number of smaller vessels with multiple types of I-V PMs (Esau, 1948; Sun et al., 2006). Vessels in secondary xylem are also different from those in primary xylem in forming vessel groups and in the number of parenchyma cells associated with a vessel (as seen in transverse sections of xylem tissue). These features of secondary xylem can affect the initial entry and subsequent I-V movement of the pathogen and the formation of vascular occlusions, respectively, in stems containing significant amounts of secondary xylem. Recently, the X. fastidiosa population size only in stems with secondary xylem was found to correlate with the grapevine’s resistance to PD (Baccari and Lindow, 2011), indicating an important role of stem secondary xylem in determining a host vine’s disease resistance. Despite these facts, little is known about the pathogen-grapevine interactions in the stem secondary xylem and their possible impacts on disease development.This study addresses X. fastidiosa-grapevine interactions in stem secondary xylem and examines the resulting impacts on overall vine physiology, with a primary focus on vine water transport. We have made use of grapevine genotypes displaying different PD resistances and explored whether differences in the pathogen’s induction of vascular occlusions occur among the genotypes and, if so, how the differences impact X. fastidiosa’s systemic spread. Our overall, longer-term aim is to elucidate the functional role of vascular occlusions in PD development, an understanding that we view to be essential for identifying effective approaches for controlling this devastating disease.     

Insights into Distinct Modulation of α7 and α7β2 Nicotinic Acetylcholine Receptors by the Volatile Anesthetic Isoflurane

Nicotinic acetylcholine receptors (nAChRs) are targets of general anesthetics, but functional sensitivity to anesthetic inhibition varies dramatically among different subtypes of nAChRs. Potential causes underlying different functional responses to anesthetics remain elusive. Here we show that in contrast to the α7 nAChR, the α7β2 nAChR is highly susceptible to inhibition by the volatile anesthetic isoflurane in electrophysiology measurements. Isoflurane-binding sites in β2 and α7 were found at the extracellular and intracellular end of their respective transmembrane domains using NMR. Functional relevance of the identified β2 site was validated via point mutations and subsequent functional measurements. Consistent with their functional responses to isoflurane, β2 but not α7 showed pronounced dynamics changes, particularly for the channel gate residue Leu-249(9′). These results suggest that anesthetic binding alone is not sufficient to generate functional impact; only those sites that can modulate channel dynamics upon anesthetic binding will produce functional effects.     

Tethered Spectroscopic Probes Estimate Dynamic Distances with Subnanometer Resolution in Voltage-Dependent Potassium Channels

Measurements of inter- and intramolecular distances are important for monitoring structural changes and understanding protein interaction networks. Fluorescence resonance energy transfer and functionalized chemical spacers are the two predominantly used strategies to map short-range distances in living cells. Here, we describe the development of a hybrid approach that combines the key advantages of spectroscopic and chemical methods to estimate dynamic distance information from labeled proteins. Bifunctional spectroscopic probes were designed to make use of adaptable-anchor and length-varied spacers to estimate molecular distances by exploiting short-range collisional electron transfer. The spacers were calibrated using labeled polyproline peptides of defined lengths and validated by molecular simulations. This approach was extended to estimate distance restraints that enable us to evaluate the resting-state model of the Shaker potassium channel.     

单纯疱疹病毒1型引起的发热出疹性疾病需要与手足口病进行鉴别

对2008年在甘肃省发生的一起疑似手足口病(HFMD)的发热出疹性疾病的流行进行病原体的实验室检测,明确引起这起传染病流行的病原体。从4名发热出疹患者采集的8份临床标本中(每个患者采集咽拭子和疱疹液标本),首先将临床标本接种到RD和HEp-2细胞上进行病毒分离,对病毒分离阳性的标本提取病毒核酸,然后使用荧光定量-逆转录-聚合酶链式反应(RT-PCR)进行人肠道病毒(HEV)核酸的检测。对HEV检测结果阴性的标本采用序列非依赖的单引物扩增技术(SISPA)进行"未知病原体"的鉴定。分离到的6株病毒均鉴定为单纯疱疹病毒I型(HSV-1),结合分析这起流行中患者的临床表现、流行病学调查结果以及实验室检测结果,表明HSV-1是引起这起发热出疹性疾病流行的病原体。6株HSV-1的gG区核苷酸和氨基酸水平上差异都较小,同源性分别高达98.8%和97.9%,说明这起疫情是由同一个病毒传播链引起的。HSV-1等病毒引起的发热出疹性疾病需要与HFMD进行鉴别诊断,由于仅从临床症状和流行病学资料上判断引起发热出疹性疾病的病原体是非常困难的,因此,必须依赖于实验室的诊断。     

四川省二郎山常见被子植物资源和分布特征

二郎山国家森林公园海拔3 437 m.生态环境保护良好,植物种类繁多.为进一步了解二郎山常见被子植物种类,探讨植被的垂直地带性变化和坡向性变化,对二郎山植物进行野外实地调查取样,所采集的200余份标本进行鉴定分析,结果表明,四川二郎山常见被子植物184种,8变种,主要属蔷薇科、菊科、杜鹃花科、毛茛科等科.由于二郎山的特殊地理位置,其常见被子植物具有明显的垂直性变化和坡向性变化.