Thrombus Permeability on Dynamic CTA Predicts Good Outcome after Reperfusion Therapy

BACKGROUND AND PURPOSE

Thrombus permeability assessed on conventional CTA is associated with neurologic outcome in patients with acute ischemic stroke. We aimed to investigate whether dynamic CTA can improve the accuracy of thrombus permeability assessment and its predictive value for outcome.

MATERIALS AND METHODS

We reviewed consecutive patients with acute ischemic stroke who had occlusion of the M1 segment of the middle artery cerebral artery and underwent pretreatment perfusion CT. Thrombus permeability, determined by thrombus attenuation increase (TAI), was assessed on 26-phase dynamic CTA derived from perfusion CT. TAI_max was defined as the maximum TAI among phases; TAI_peak, as TAI of peak arterial phase; TAI_con, as TAI on phase 13. Good outcome was defined as a 3-month mRS score of ≤2.

RESULTS

One hundred four patients were enrolled in the final analysis. The median TAI_max, TAI_peak, and TAI_con were 30.1 HU (interquartile range, 13.0-50.2 HU), 9.5 HU (interquartile range, -1.6-28.7 HU), and 6.6 HU (interquartile range, -5.1-24.4 HU), respectively. Multivariable regression analyses showed that TAI_max (OR = 1.027; 95% CI, 1.007-1.048; P = .008), TAI_peak (OR = 1.029; 95% CI, 1.005-1.054; P = .020), and TAI_con (OR = 1.026; 95% CI, 1.002-1.051; P = .037) were independently associated with good outcome. The areas under the ROC curve of TAI_max, TAI_peak, and TAI_con in predicting good outcome were 0.734, 0.701, and 0.658, respectively.

CONCLUSIONS

Thrombus permeability assessed on dynamic CTA could be a better predictor of outcome after reperfusion therapy than that assessed on conventional single-phase CTA.

Nanoscale zero-valent iron assisted phytoremediation of Pb in sediment: Impacts on metal accumulation and antioxidative system of Lolium perenne

Lead (Pb) is a highly toxic environmental pollutant, and could result in toxic effects on living organisms. The effects of 0, 100, 200, 500, 1000 and 2000 mg/kg of nZVI on plant growth, Pb accumulation and antioxidative responses of Lolium perenne were investigated. Results showed that the total Pb contents in L. perenne with the treatment of low concentrations of nZVI (100, 200 and 500 mg/kg) were higher than those in the non-nZVI treatments, and the highest Pb accumulation capacity of 1175.40 μg per pot was observed in L. perenne with the treatment of 100 mg/kg nZVI. However, the total Pb contents in L. perenne decreased at high concentrations of nZVI (1000 and 2000 mg/kg). This might be resulted from the decrease of photosynthetic chlorophyll content and the aggravated oxidative stress induced by the high concentration of nZVI, which caused the decrease of plant biomass and metal accumulation capacity in plant. Moreover, the sequential extraction experiments results showed that the lowest acid soluble fraction of Pb in the sediments was found in the treatment with 100 mg/kg of nZVI, indicating that 100 mg/kg was the optimum concentration for nZVI to assist the phytoremediation of Pb-polluted sediment. To conclude, these findings provide a promising method to remediate Pb-polluted sediment by nZVI assisted phytoremediation.

[Photochemical induced vestibular ischemiawith icy water test in guinea pigs]

Objective:To ascertain the effects of a new method of photochemical reaction in vestibular function in guinea pigs.Method:Local photochemical reaction was initiated by systemic injection of rose bengal(20mg), photoillumination of the vestibule through medial wall of epitympanum for 30 minutes was started immediately after the injection of rose bengal, with a optic fiber connected to a xenon light (wavelength, 540nm; photointense, 500-600 mW/cm ²). There were 20 guinea pigs divided random equally into 2 groups. Group 1 was injected with rose bengal. Group 2 was control, injected with physiological saline solution. The ice caloric tests were performed on the second day.Result:The test group (7 ears) and the control group (6 ears) with test nystagmus showed mean frequencies were（2.0±0.33）times/s and（3.7±0.33）times/s,the mean amplitude were (3.1±0.39)mm and (3.5±0.54)mm,and the mean duration were (44.7±17.22)s and (62.0±7.22)s respectively.The nystagmus frequency difference was statistically significant, but the amplitude and the duration of the nystagmus were not significantly different. There was no obvious spontaneous nystagmus in the two groups, and there were negative results of ice water test (3 ears in the test group and 4 ears in the control group).Conclusion:Photochemical reaction can induce the ischemic state of the vestibule system in guinea pig, and produce an acute vestibular dysfunction, and ice water test shows that the frequency of nystagmus is reduced.

Prediction of the Multisegment Clot Sign on Dynamic CT Angiography of Cardioembolic Stroke

BACKGROUND AND PURPOSE

The multisegment clot sign has been observed at the site of large-artery occlusion in patients with acute ischemic stroke. This study aimed to assess its occurrence rate and relationship with stroke etiologies in patients with acute intracranial large-artery occlusion.

MATERIALS AND METHODS

We included consecutive patients with acute ischemic stroke who had acute intracranial large-artery occlusion and underwent perfusion CT within 8 hours after stroke onset. The multisegment clot sign was assessed on dynamic CT angiography derived from perfusion CT. The stroke etiologies were defined by the international Trial of Org 10172 in Acute Stroke Treatment criteria. Poisson regression analyses and diagnostic testing were used to investigate the relationship between the multisegment clot sign and stroke etiologies.

RESULTS

Finally, 194 patients with intracranial large-artery occlusion were enrolled. According to the Trial of Org 10172 in Acute Stroke Treatment criteria, 110 (56.7%) patients were diagnosed with cardioembolism; 43 (22.2%), with large-artery atherosclerosis; and 41 (21.1%), with undetermined etiology. The multisegment clot sign was found in 74 (38%) patients. Poisson regression analysis showed that the presence of the multisegment clot sign was significantly higher in patients with cardioembolism than in those with large-artery atherosclerosis (52.7% versus 9.3%; prevalence ratio, 1.53; 95% confidence interval, 1.03-2.90; P = .037). For determined etiologies, the sensitivity, specificity, and positive and negative predictive values of the multisegment clot sign for predicting cardioembolism were 52.7%, 90.7%, 93.5%, and 42.9%, respectively.

CONCLUSIONS

The presence of the multisegment clot sign on dynamic CTA specifically indicates intracranial large-artery occlusion caused by an embolism from a cardiac source, which may be useful for acute management and secondary prevention of stroke.

Pyrolysis and reutilization of plant residues after phytoremediation of heavy metals contaminated sediments: For heavy metals stabilization and dye adsorption

This study aimed to investigate the effect of pyrolysis on the stabilization of heavy metals in plant residues obtained after phytoremediation. Ramie residues, being collected after phytoremediation of metal contaminated sediments, were pyrolyzed at different temperatures (300-700 °C). Results indicated that pyrolysis was effective in the stabilization of Cd, Cr, Zn, Cu, and Pb in ramie residues by converting the acid-soluble fraction of metals into residual form and decreasing the TCLP-leachable metal contents. Meanwhile, the reutilization potential of using the pyrolysis products generated from ramie residues obtained after phytoremediation as sorbents was investigated. Adsorption experiments results revealed that the pyrolysis products presented excellent ability to adsorb methylene blue (MB) with a maximum adsorption capacity of 259.27 mg/g. This study demonstrated that pyrolysis could be used as an efficient alternative method for stabilizing heavy metals in plant residues obtained after phytoremediation, and their pyrolysis products could be reutilized for dye adsorption.

Puerarin Stimulates Osteogenic Differentiation and Bone Formation Through the ERK1/2 and p38-MAPK Signaling Pathways

BACKGROUND

Osteoporosis is a world-wide health problem, which leads to decreased bone strength and increased susceptibility to fractures. Puerarin, a phytoestrogen extracted from Pueraria lobata (Willd.) Ohwi, has been identified as a promising intervention for preventing bone loss and promoting bone regeneration. However, the underlying mechanisms for its anabolic action are still not clear. In the present study, we aimed to investigate the effect of puerarin on the osteogenic differentiation of bone marrow stromal cells (BMSCs) and the possible molecular mechanism mediating its action.

METHODS

Bone marrow stromal cells (BMSCs) and intragastric administration on ovariectomized(OVX) rats were used to study the anti-osteoporotic function of puerarin. The involvement of mitogen-activated protein kinase (MAPK) signaling pathways was determined.

RESULTS

Our results demonstrated that at optimal concentration, puerarin could promote osteogenic differentiation of BMSCs in vitro. This induction was mediated by MAPK signaling pathway. Further detailed study revealed that ERK1/2-Runx2 signaling pathway had more prominent effect than p38 signaling pathway in puerarin-induced differentiation of BMSCs toward the osteogenic phenotype. We also found that puerarin protected against reduction in bone mineral density and improved femur trabecular bone structure in ovariectomized rats.

CONCLUSION

Our findings revealed the functional mechanism of puerarin in promoting osteogenic differentiation which involved ERK1/2 and p38-MAPK pathway and provided experimental evidence for the potential application of puerarin for estrogen replacement therapy of osteoporosis.

Transcriptome analysis reveals novel insights into the response to Pb exposure in Phanerochaete chrysosporium

Metals released into the environment continue to be of concern for human health. Using white-rot fungi as biosorbents for heavy metals removal is an attractive alternative owing to its good performance and low cost. However, the molecular mechanism underlying heavy metal tolerance in white-rot fungi has not yet been fully elucidated. This study identified and analyzed the lead (Pb)-induced transcriptional changes in Phanerochaete chrysosporium, a well-known heavy metal hyperaccumulating white-rot fungus. The results confirmed its outstanding ability in Pb tolerance and effective defense system. By comparative analysis of gene expression profiles obtained from cDNA-amplified fragment length polymorphism (cDNA-AFLP), we isolated 43 transcript-derived fragments (TDFs) differentially regulated by Pb exposure in P. chrysosporium, and 23 TDFs presented significant similarities to genes encoding known or putative proteins which belong to different functional categories involving ion binding, energy and carbohydrate metabolism, and signal transduction. The detailed characterization of these Pb-responsive genes was presented and the expression patterns of some interesting genes were validated by quantitative RT-PCR. This work provides the first evidence of Pb-responsive genes along with their putatively functional annotations in P. chrysosporium, which may help to understand the mechanism underlying heavy metal accumulation and tolerance in P. chrysosporium.

Rhamnolipid stabilized nano-chlorapatite: Synthesis and enhancement effect on Pb-and Cd-immobilization in polluted sediment

Phosphate (P) compounds are usually used as chemical amendment for in situ remediation of heavy metal polluted sediment. However, the low deliverability, weak utilization and potential risk of eutrophication inhibit the application of most P materials. Therefore, rhamnolipid (Rha), a kind of anionic biosurfactant which has algicidal activity, was employed in this study to synthesize a new kind of nano-chlorapatite (nClAP) for Pb and Cd immobilization. Characterization results showed that the Rha stablized nClAP (Rha-nClAP) was uniformly distributed in suspensions within about 5nm. Experimental data demonstrated that the combination of Rha and nClAP could greatly enhance the Pb- and Cd-immobilization efficiencies, promoting their transformation from labile fractions to stable fractions through precipitation or adsorption processes, especially when the Rha approached to its critical micelle concentration. And Rha-nClAP could also decrease both the TCLP-leachable Pb and Cd with maximum reduction efficiencies of 98.12% and 96.24%, respectively, which also presented concentration dependence of Rha. Changes of available phosphorus implied the dissolution of nClAP during the treatment and the detection of organic matter demonstrated that the microorganisms may involve in the remediation.

White rot fungi and advanced combined biotechnology with nanomaterials: promising tools for endocrine-disrupting compounds biotransformation

Endocrine-disrupting compounds (EDCs) can interfere with endocrine systems and bio-accumulate through the food chain and even decrease biodiversity in contaminated areas. This review discusses a critical overview of recent research progress in the biotransformation of EDCs (including polychlorinated biphenyl and nonylphenol, and suspected EDCs such as heavy metals and sulfonamide antibiotics) by white rot fungi (WRF) based on techniques with an emphasis on summarizing and analyzing fungal molecular, metabolic and genetic mechanisms. Not only intracellular metabolism which seems to perform essential roles in the ability of WRF to transform EDCs, but also advanced applications are deeply discussed. This review mainly reveals the removal pathway of heavy metal and antibiotic pollutants because the single pollution almost did not exist in a real environment while the combined pollution has become more serious and close to people's life. The trends in WRF technology and its related advanced applications which use the combined technology, including biocatalysis of WRF and adsorption of nanomaterials, to degrade EDCs have also been introduced. Furthermore, challenges and future research needs EDCs biotransformation by WRF are also discussed. This research, referring to metabolic mechanisms and the combined technology of WRF with nanomaterials, undoubtedly contributes to the applications of biotechnology. This review will be of great benefit to an understanding of the trends in biotechnology for the removal of EDCs.

RAF inhibitor LY3009120 sensitizes RAS or BRAF mutant cancer to CDK4/6 inhibition by abemaciclib via superior inhibition of phospho-RB and suppression of cyclin D1

KRAS, NRAS and BRAF mutations are among the most important oncogenic drivers in many major cancer types, such as melanoma, lung, colorectal and pancreatic cancer. There is currently no effective therapy for the treatment of RAS mutant cancers. LY3009120, a pan-RAF and RAF dimer inhibitor advanced to clinical study has been shown to inhibit both RAS and BRAF mutant cell proliferation in vitro and xenograft tumor growth in vivo. Abemaciclib, a CDK4/6-selective inhibitor, is currently in phase III studies for ER-positive breast cancer and KRAS mutant lung cancer. In this study, we found that combinatory treatment with LY3009120 and abemaciclib synergistically inhibited proliferation of tumor cells in vitro and led to tumor growth regression in xenograft models with a KRAS, NRAS or BRAF mutation at the doses of two drugs that were well tolerated in combination. Further in vitro screen in 328 tumor cell lines revealed that tumor cells with KRAS, NRAS or BRAF mutation, or cyclin D activation are more sensitive, whereas tumor cells with PTEN, PIK3CA, PIK3R1 or retinoblastoma (Rb) mutation are more resistant to this combination treatment. Molecular analysis revealed that abemaciclib alone inhibited Rb phosphorylation partially and caused an increase of cyclin D1. The combinatory treatment cooperatively demonstrated more complete inhibition of Rb phosphorylation, and LY3009120 suppressed the cyclin D1 upregulation mediated by abemaciclib. These results were further verified by CDK4/6 siRNA knockdown. Importantly, the more complete phospho-Rb inhibition and cyclin D1 suppression by LY3009120 and abemaciclib combination led to more significant cell cycle G₀/G₁ arrest of tumor cells. These preclinical findings suggest that combined inhibition of RAF and d-cyclin-dependent kinases might provide an effective approach to treat patients with tumors harboring mutations in RAS or RAF genes.

Precipitation, adsorption and rhizosphere effect: The mechanisms for Phosphate-induced Pb immobilization in soils-A review

Lead (Pb) is one of the most toxic heavy metals that pose a direct threat to organisms and it can not been degraded through microbial activities or chemical reaction. Bioavaibility and eco-toxicity of Pb which mostly depend on Pb chemical speciation play an important role in the remediation of Pb-contaminated soils. Phosphate (P) amendments which could transfer Pb from unstable fraction to stable fraction are commonly used to immobilize Pb in soils and have been extensively studied by researchers during decades. Based on the previous study, it can be concluded that three principal mechanisms may be responsible for P-induced Pb immobilization: 1) the precipitation of Pb-phosphates, including direct precipitation, ion-exchange (or substitution) effect and liming effect; 2) the adsorption of Pb, including the direct adsorption and the adsorption of Pb to iron (hydr)oxides; 3) the rhizosphere effect, including acidification effect and mycorrhizae effect. In this review, these mechanisms have been completely discussed and the internal relationships among them were summarized to give a better understanding of P-induced Pb immobilization in soils and promote the development of P-based remediation technology.

Stabilized Nanoscale Zerovalent Iron Mediated Cadmium Accumulation and Oxidative Damage of Boehmeria nivea (L.) Gaudich Cultivated in Cadmium Contaminated Sediments

Nanoparticles can be absorbed by plants, but their impacts on phytoremediation are not yet well understood. This study was carried out to determine the impacts of starch stabilized nanoscale zerovalent iron (S-nZVI) on the cadmium (Cd) accumulation and the oxidative stress in Boehmeria nivea (L.) Gaudich (ramie). Plants were cultivated in Cd-contaminated sediments amended with S-nZVI at 100, 500, and 1000 mg/kg, respectively. Results showed that S-nZVI promoted Cd accumulation in ramie seedlings. The subcellular distribution result showed that Cd content in cell wall of plants reduced, and its concentration in cell organelle and soluble fractions increased at S-nZVI treatments, indicating the promotion of Cd entering plant cells by S-nZVI. In addition, the 100 mg/kg S-nZVI alleviated the oxidative damage to ramie under Cd-stress, while 500 and 1000 mg/kg S-nZVI inhibited plant growth and aggravated the oxidative damage to plants. These findings demonstrate that nanoparticles at low concentration can improve the efficiency of phytoremediation. This study herein develops a promising novel technique by the combined use of nanotechnology and phytoremediation in the remediation of heavy metal contaminated sites.

Abdominal obesity and risk of hip fracture: a meta-analysis of prospective studies

We conducted a meta-analysis to qualitatively summarize the evidence of the association between abdominal obesity and hip fracture risk. The results indicated that abdominal obesity as measured by waist circumference and waist-hip ratio might be associated with an increased risk of hip fracture.

INTRODUCTION

Epidemiological investigations evaluating the association of abdominal obesity with hip fracture risk have yielded conflicting results. Therefore, a meta-analysis was conducted to qualitatively summarize the evidence of the associations between waist circumference, waist-hip ratio, and hip circumference and the risk of hip fracture, respectively.

METHODS

PubMed, Embase, and Web of Science were searched for relevant articles published up to March 2017. Pooled relative risks (RRs) with 95% confidence intervals (CIs) were calculated with a random-effects model. Dose-response relationship was assessed by restricted cubic spline.

RESULTS

Seven studies involving 180,600 participants for hip circumference, six studies involving 199,828 participants for waist-hip ratio, and five studies involving 170,796 participants for waist circumference were finally included in this meta-analysis. The combined RRs with 95% CIs of hip fracture for the highest versus lowest category of waist circumference, waist-hip ratio, and hip circumference were 1.58 (95% CI 1.20-2.08), 1.32 (95% CI 1.15-1.52), and 0.87 (95% CI 0.74-1.02), respectively. For dose-response analysis, a nonlinear relationship was found (P _nonlinearity < 0.001) between waist circumference and the risk of hip fracture, and a linear relationship (P _nonlinearity = 0.911) suggested that the risk of hip fracture increased about 3.0% (1.03 (1.01-1.04)) for each 0.1 unit increment of waist-hip ratio.

CONCLUSIONS

This meta-analysis suggested that abdominal obesity as measured by waist circumference and waist-hip ratio might be associated with an increased risk of hip fracture. From a public health perspective, indicators of abdominal obesity may be usable predictors of hip fracture risk.

Real-Time Motor Cortex Mapping for the Safe Resection of Glioma: An Intraoperative Resting-State fMRI Study

BACKGROUND AND PURPOSE

Resting-state functional MR imaging has been used for motor mapping in presurgical planning but never used intraoperatively. This study aimed to investigate the feasibility of applying intraoperative resting-state functional MR imaging for the safe resection of gliomas using real-time motor cortex mapping during an operation.

MATERIALS AND METHODS

Using interventional MR imaging, we conducted preoperative and intraoperative resting-state intrinsic functional connectivity analyses of the motor cortex in 30 patients with brain tumors. Factors that may influence intraoperative imaging quality, including anesthesia type (general or awake anesthesia) and tumor cavity (filled with normal saline or not), were studied to investigate image quality. Additionally, direct cortical stimulation was used to validate the accuracy of intraoperative resting-state fMRI in mapping the motor cortex.

RESULTS

Preoperative and intraoperative resting-state fMRI scans were acquired for all patients. Fourteen patients who successfully completed both sufficient intraoperative resting-state fMRI and direct cortical stimulation were used for further analysis of sensitivity and specificity. Compared with those subjected to direct cortical stimulation, the sensitivity and specificity of intraoperative resting-state fMRI in localizing the motor area were 61.7% and 93.7%, respectively. The image quality of intraoperative resting-state fMRI was better when the tumor cavity was filled with normal saline (P = .049). However, no significant difference between the anesthesia types was observed (P = .102).

CONCLUSIONS

This study demonstrates the feasibility of using intraoperative resting-state fMRI for real-time localization of functional areas during a neurologic operation. The findings suggest that using intraoperative resting-state fMRI can avoid the risk of intraoperative seizures due to direct cortical stimulation and may provide neurosurgeons with valuable information to facilitate the safe resection of gliomas.

[Effect of sandblasting on bending strength and subcritical crack growth of the dental zirconia ceramics]

Objective: To evaluate the effect of sandblasting on bending strength and subcritical crack growth (SCG) under cyclic loading of yttria-stabilized tetragonal zirconia polycrystal (Y-TZP) ceramics. Methods: After being polished, sixty bar-shaped specimens of Y-TZP (Wieland zirconia ceramics) were assigned to two groups (n=30) according to the random number table, the sandblasting group (SG) which was treated with sandblasting and the control group (CG) which remained untouched. In each group, half of the specimens (n=15) were subjected to bending strength test, and the results were examined by Weibull statistics and analyzed with ANOVA. The other 15 specimens in each group were subjected to fatigue tests. The results were examined by Weibull statistics and subcritical crack propagation rates were calculated. Results: The bending strengths of SG and CG were (1 291±133) and (1 140±124) MPa (F=10.117, P=0.004), and the Weibull modules of the two groups were 11.06 and 10.64 respectively. The crack growth rate of SCG of SG was lower than that of CG under the same cyclic loading. Conclusions: Proper sandblasting on Y-TZP ceramic can increase its bending strength and resistance to SCG.

Effects of calcium at toxic concentrations of cadmium in plants

This review provides new insight that calcium plays important roles in plant growth, heavy metal accumulation and translocation, photosynthesis, oxidative damage and signal transduction under cadmium stress. Increasing heavy metal pollution problems have raised word-wide concerns. Cadmium (Cd), being a highly toxic metal, poses potential risks both to ecosystems and human health. Compared with conventional technologies, phytoremediation, being cost-efficient, highly stable and environment-friendly, is believed to be a promising green technology for Cd decontamination. However, Cd can be easily taken up by plants and may cause severe phytotoxicity to plants, thus limiting the efficiency of phytoremediation. Various researches are being done to investigate the effects of exogenous substances on the mitigation of Cd toxicity to plants. Calcium (Ca) is an essential plant macronutrient that involved in various plant physiological processes, such as plant growth and development, cell division, cytoplasmic streaming, photosynthesis and intracellular signaling transduction. Due to the chemical similarity between Ca and Cd, Ca may mediate Cd-induced physiological or metabolic changes in plants. Recent studies have shown that Ca could be used as an exogenous substance to protect plants against Cd stress by the alleviation of growth inhibition, regulation of metal uptake and translocation, improvement of photosynthesis, mitigation of oxidative damages and the control of signal transduction in the plants. The effects of Ca on toxic concentrations of Cd in plants are reviewed. This review also provides new insight that plants with enhanced Ca level have improved resistance to Cd stress.

Effects of calcium at toxic concentrations of cadmium in plants

This review provides new insight that calcium plays important roles in plant growth, heavy metal accumulation and translocation, photosynthesis, oxidative damage and signal transduction under cadmium stress. Increasing heavy metal pollution problems have raised word-wide concerns. Cadmium (Cd), being a highly toxic metal, poses potential risks both to ecosystems and human health. Compared with conventional technologies, phytoremediation, being cost-efficient, highly stable and environment-friendly, is believed to be a promising green technology for Cd decontamination. However, Cd can be easily taken up by plants and may cause severe phytotoxicity to plants, thus limiting the efficiency of phytoremediation. Various researches are being done to investigate the effects of exogenous substances on the mitigation of Cd toxicity to plants. Calcium (Ca) is an essential plant macronutrient that involved in various plant physiological processes, such as plant growth and development, cell division, cytoplasmic streaming, photosynthesis and intracellular signaling transduction. Due to the chemical similarity between Ca and Cd, Ca may mediate Cd-induced physiological or metabolic changes in plants. Recent studies have shown that Ca could be used as an exogenous substance to protect plants against Cd stress by the alleviation of growth inhibition, regulation of metal uptake and translocation, improvement of photosynthesis, mitigation of oxidative damages and the control of signal transduction in the plants. The effects of Ca on toxic concentrations of Cd in plants are reviewed. This review also provides new insight that plants with enhanced Ca level have improved resistance to Cd stress.