Effect of pain location on spatial reorganisation of muscle activity

IntroductionWe aimed to determine whether the changes in muscle activity (in terms of both gross electromyography (EMG) and motor unit (MU) discharge characteristics) observed during pain are spatially organized with respect to pain location within a muscle which is the main contributor of the task.MethodsSurface and fine-wire EMG was recorded during matched low-force isometric plantarflexion from soleus (from four quadrants with fine-wire EMG and from the medial/lateral sides with surface EMG), both gastrocnemii heads, peroneus longus, and tibialis anterior. Four conditions were tested: two control conditions that each preceded contractions with pain induced in either the lateral (Pain_L) or medial (Pain_M) side of soleus.ResultsNeither the presence (p = 0.28) nor location (p = 0.19) of pain significantly altered gross muscle activity of any location (lateral/medial side of soleus, gastrocnemii, peroneus longus and tibialis anterior). Group data from 196 MUs show redistribution of MU activity throughout the four quadrants of soleus, irrespective of pain location. The significant decrease of MU discharge rate during pain (p < 0.0001; Pain_L: 7.3 ± 0.9–6.9 ± 1.1 Hz, Pain_M: 7.0 ± 1.1 to 6.6 ± 1.1 Hz) was similar for all quadrants of the soleus (p = 0.43), regardless of the pain location (p = 0.98). There was large inter-participant variation in respect to the characteristics of the altered MU discharge with pain.ConclusionResults from both surface and fine-wire EMG recordings do not support the hypothesis that muscle activity is reorganized in a simple systematic manner with respect to pain location.     

高渗盐水雾化吸入治疗儿童支原体肺炎继发哮喘发作及对其T淋巴细胞亚群及Th1、Th2型细胞因子的影响

目的:探讨高渗盐水雾化吸入治疗儿童支原体肺炎继发哮喘发作的临床疗效及对其T淋巴细胞亚群及Th1、Th2型细胞因子的影响。方法:选取我院2015年6月到2017年6月间收治的支原体肺炎继发哮喘发作患儿100例为研究对象。随机分为对照组和观察组,各50例。两组均给予吸氧、抗生素、维持酸碱度、电解质平衡及相应症状等对症治疗,对照组给予生理盐水结合沙丁胺醇进行雾化治疗,观察组采用3%高渗盐水结合沙丁胺醇进行雾化治疗,比较两组患儿发热、咳嗽、肺内啰音、咽部肿痒等症状消失时间及临床疗效;比较两组治疗前后CD3~+、CD4~+、CD8~+、CD4~+/CD8~+、IFN-γ及IL-4水平情况。结果:观察组患儿发热、咳嗽、肺内啰音、咽部肿痒等临床症状消失时间显著早于对照组,差异有统计学意义(P0.05);观察组总有效率96.00%明显高于对照组80.00%,差异有统计学意义(P0.05);两组患儿治疗前CD3~+、CD4~+、CD8~+、CD4~+/CD8~+、IFN-γ及IL-4水平比较差异无统计学意义(P0.05);治疗后CD3~+、CD4~+、CD4~+/CD8~+及IFN-γ水平均明显升高,CD8~+及IL-4水平明显降低,差异均有统计学意义(均P0.05);且观察组治疗后CD3~+、CD4~+、CD4~+/CD8~+及IFN-γ水平均明显高于对照组,CD8~+及IL-4水平明显低于对照组,差异均有统计学意义(均P0.05)。结论:高渗盐水雾化吸入能够显著改善支原体肺炎继发哮喘发作患儿临床症状,提高CD3~+、CD4~+、CD4~+/CD8~+及Th1水平,抑制CD8~+及Th2水平,临床疗效确切,值得临床推广应用。     

Quantitative microinjection of trehalose into mouse oocytes and zygotes,and its effect on development

Sugars such as trehalose are effectively used by various organisms as protective agents to undergo anhydrobiosis and cryobiosis. The objective of this study was first to establish a method for quantitative delivery of trehalose as a model sugar into oocytes, and then to evaluate its effect on development of mouse zygotes. To this end, a quantitative microinjection technique was developed using volumetric response of microdroplets suspended in dimethylpolysilaxene. To verify accuracy of this technique, both microdroplets and oocytes were microinjected with fluorophore-labeled dextran. Thereafter, injection volumes were calculated from fluorescence intensity, and volumetric responses of both microdroplets and oocytes. Comparison of calculated injection volumes revealed that this technique reflects microinjection into oocytes with pL-accuracy. The next series of experiments focused on toxicity of injection buffers (i.e., 10mM Tris and 15mM Hepes) and trehalose. Microinjection of Hepes and Tris buffer in the presence of 0.1M trehalose resulted in blastocyst rates of 86 and 72%, respectively, without a significant difference when compared to controls (86%). In subsequent experiments, Hepes was used as the injection buffer, and embryonic development of zygotes was studied as a function of intracellular trehalose concentrations. Microinjection of trehalose up to 0.15M resulted in development to blastocyst stage similar to controls (85 and 87%, respectively) while the blastocyst rate was significantly decreased (43%) in the presence of 0.20M intracellular trehalose. When transferred to foster mothers, trehalose-injected zygotes (0.1M) implanted and developed to day 16 fetuses similar to controls, healthy pups were born. The findings of this study suggest that trehalose at effective intracellular concentrations does not impair development of mouse zygotes.     

等渗透剂量的7.5%高渗盐水和20%甘露醇治疗颅内高压疗效的对比研究

目的:比较等渗透剂量的7.5%高渗盐水(hypertonic saline,HTS)和20%甘露醇治疗颅高压的疗效。方法:当患者的颅内压(intracranial pressure,ICP)超过20 mm Hg时,一组患者接受了4 m L/kg 7.5%HTS(HTS组,n=27),另外一组患者接受了0.5 g/kg 20%甘露醇(甘露醇组,n=31)的降颅压治疗,两种药物均经深静脉在30 min内快速滴注完成。用药期间,连续监测患者ICP,平均动脉压(mean arterial pressure,MAP)、脑灌注压(cerebral perfusion pressure,CPP)及中心静脉压(central venous pressure,CVP)。记录有效降颅压持续时间、ICP最大降幅及其时间,用药前及用药后1 h、3 h、6 h抽血查电解质和血浆渗透压等。结果:静脉快速滴注7.5%HTS和20%甘露醇后,两者均可有效降低ICP(P0.05)。两组在控制颅高压的有效率、起效时间及ICP降幅无统计学差异(P0.05),但HTS组的作用持续时间要明显长于甘露醇组(P0.05)。两组渗透压较用药前相比均有显著上升(P0.05)。用药前后,两组MAP、CPP和CVP变化无统计学差异(P0.05)。结论:等渗透剂量的7.5%HTS与20%甘露醇均可有效降低患者的ICP,两者降颅压效果相当,均可作为治疗颅内高压的一线治疗药物。     

Effects of hyperosmotic stress on cultured airway epithelial cells

Inhalation of hyperosmotic solutions (salt, mannitol) has been used in the treatment of patients with cystic fibrosis or asthma, but the mechanism behind the effect of hyperosmotic solutions is unclear. The relation between osmolarity and permeability changes was examined in an airway cell line by the addition of NaCl, NaBr, LiCl, mannitol, or xylitol (295–700 mOsm). Transepithelial resistance was measured as an indicator of the tightness of the cultures. Cell-cell contacts and morphology were investigated by immunofluorescence and by transmission electron microscopy, with lanthanum nitrate added to the luminal side of the epithelium to investigate tight junction permeability. The electrolyte solutions caused a significant decrease in transepithelial resistance from 450 mOsm upwards, when the hyperosmolar exposure was gradually increased from 295 to 700 mOsm; whereas the nonelectrolyte solutions caused a decrease in transepithelial resistance from 700 mOsm upwards. Old cultures reacted in a more rigid way compared to young cultures. Immuno-fluorescence pictures showed weaker staining for the proteins ZO-1, claudin-4, and plakoglobin in treated samples compared to the control. The ultrastructure revealed an increased number of open tight junctions as well as a disturbed morphology with increasing osmolarity, and electrolyte solutions opened a larger proportion of tight junctions than nonelectrolyte solutions. This study shows that hyperosmotic solutions cause the opening of tight junctions, which may increase the permeability of the paracellular pathway and result in increased transepithelial water transport. This study was supported by the Swedish Asthma and Allergy Association and the Swedish Heart Lung Foundation.     

Extrusion and removal of lipid from the cytoplasm of porcine oocytes at the germinal vesicle stage: centrifugation under hypertonic conditions influences vitrification

In the present study, we examined a novel lipid removal method, centrifugation in solutions made hypertonic by adding 0.27 M sugar. This allowed the lipid to be extruded and removed without the loss of active mitochondria or extra cytoplasm. The type of sugar influenced the proportion of oocytes that could be stratified by centrifugation. Glucose induced the highest extrusion rate of lipid droplets. After vitrification the rates of survival, germinal vesicle breakdown and metaphase II were 30, 26, and 7%, respectively, for lipid-removed GV oocytes; this was significantly higher (P<0.05) than for corresponding vitrified lipid-intact oocytes (2, 0, and 0%, respectively). These results indicated that this method is useful to remove whole lipid droplets without losing mitochondria and improves cryotolerance of porcine GV oocytes.     

Hypertonic Saline Attenuates Colonic Tumor Cell Metastatic Potential by Activating Transmembrane Sodium Conductance

Hypertonic saline (HTS) suppresses tumor cell-endothelial interactions by reducing integrin expression. This translates into reduced adhesion, migration and metastatic potential. This study determined the relative contributions of hyperosmolarity and sodium-specific hypertonicity on the inhibitory effects of HTS, the intracellular pH and sodium responses to HTS and the role of cytoskeletal remodeling in these changes. Human colonic tumor cells (LS174T) were exposed to lipopolysaccharide under isotonic, hypertonic, sodium-free (N-methyl- D-glucamine), hyperosmolar (mannitol or urea), disrupted cytoskeletal (10 μg/ml cytochalasin D) conditions or in the presence of 5-(N-ethyl-N-isopropyl)amiloride (EIPA). β₁ integrin expression was measured flow-cytometrically. Intracellular sodium and pH were measured with confocal laser microscopic imaging. Statistical analysis was performed with analysis of variance, and P < 0.05 was considered significant. Data are represented as mean ± SEM. Hypertonic exposure attenuated integrin expression (62.03 ± 4.7% of control, P < 0.04). No discernible effect was observed with sodium-free or hyperosmolar solutions. HTS evoked a cellular alkalinization (by a mean 0.2 pH units) and an increase in cytosolic sodium concentration (by a mean 12.4 mM, P < 0.001) via upregulation of sodium-hydrogen exchange. Disassembly of actin microfilaments by cytochalasin D and antiporter inhibition with EIPA abrogated the effect of hypertonicity on integrin expression and intracellular sodium and pH (P < 0.05). HTS downregulates adhesion molecule expression via a hypertonic, sodium-specific, cytoskeletally mediated mechanism that involves activation of sodium-hydrogen exchange with associated changes in intracellular pH and sodium concentrations.     

Mechanisms to avoid photoinhibition in a desiccation-tolerant cyanobacterium, Nostoc commune

A desiccation-tolerant cyanobacterium, Nostoc commune, showsunique responses to dehydration. These responses are: (i) lossof PSII activity in parallel with the loss of photosynthesis;(ii) loss of PSI activity; and (iii) dissipation of light energyabsorbed by pigment–protein complexes. In this study,the deactivation of PSII is shown to be important in avoidingphotoinhibition when the Calvin–Benson cycle is repressedby dehydration. Furthermore, our evidence suggests that dissipationof light energy absorbed by PSII blocks photoinhibition understrong light in dehydrated states.     

Lipid based nanoparticles containing saturated solution of NaCl, may be used to targeted eradication of cancerous cells

Different strategies used for treatment of cancer which has some major side effects. In this paper we hypothesized targeted delivery lipid based nanoparticles containing saturated solution of NaCl for elimination of cancerous cells.     

Cryobiological properties of immature zebrafish oocytes assessed by their ability to be fertilized and develop into hatching embryos

As a step to develop a cryopreservation method for zebrafish oocytes, we investigated the cryobiological properties of immature oocytes at stage III by examining their ability to mature and to develop into hatching embryos after fertilization. When oocytes were chilled at −5 °C for 30 min, the maturation rate decreased, but the rates of fertilization and hatching were not significantly different from those of controls. When oocytes were exposed to hypotonic solutions for 60 min at 25 °C, the rates of maturation, fertilization, and hatching decreased in a solution with 0.16 Osm/kg or below. When oocytes were exposed to hypertonic solutions (containing sucrose) at 25 °C for 30 min, the maturation rate decreased in solution with 0.51 Osm/kg, whereas the hatching rate decreased with lower osmolality (0.40 Osm/kg). In an experiment on the toxicity of cryoprotectants (∼10%, at 25 °C), it was found that glycerol and ethylene glycol were toxic both by the assessment of maturation and hatching. Propylene glycol, DMSO and methanol were less toxic by the assessment of maturation, but were found to be toxic by the assessment of hatching. Methanol was the least toxic, but it was less effective to make a solution vitrify than propylene glycol. Therefore, a portion of methanol was replaced with propylene glycol. The replacement increased the toxicity, but could be effective to reduce chilling injury at −5 °C. These results clarified the sensitivity of immature oocytes to various cryobiological properties accurately, which will be useful for realizing cryopreservation of zebrafish oocytes.