The COP9 SIGNALOSOME Is Required for Postembryonic Meristem Maintenance in Arabidopsis thaliana

Cullin-RING E3 ligases (CRLs) regulate different aspects of plant development and are activated by modification of their cullin subunit with the ubiquitin-like protein NEDD8 (NEural precursor cell expressed Developmentally Down-regulated 8) (neddylation) and deactivated by NEDD8 removal (deneddylation). The constitutively photomorphogenic9 (COP9) signalosome (CSN) acts as a molecular switch of CRLs activity by reverting their neddylation status, but its contribution to embryonic and early seedling development remains poorly characterized. Here, we analyzed the phenotypic defects of csn mutants and monitored the cullin deneddylation/neddylation ratio during embryonic and early seedling development. We show that while csn mutants can complete embryogenesis (albeit at a slower pace than wild-type) and are able to germinate (albeit at a reduced rate), they progressively lose meristem activity upon germination until they become unable to sustain growth. We also show that the majority of cullin proteins are progressively neddylated during the late stages of seed maturation and become deneddylated upon seed germination. This developmentally regulated shift in the cullin neddylation status is absent in csn mutants. We conclude that the CSN and its cullin deneddylation activity are required to sustain postembryonic meristem function in Arabidopsis.

Human RNA polymerase II associated factor 1 complex promotes tumorigenesis by activating c-MYC transcription in non-small cell lung cancer

Human RNA polymerase II (RNAPII)-associated factor 1 complex (hPAF1C) plays a crucial role in protein-coding gene transcription. Overexpression of hPAF1C has been implicated in the initiation and progression of various human cancers. However, the molecular pathways involved in tumorigenesis through hPAF1C remain to be elucidated. The current study suggested hPAF1C expression as a prognostic biomarker for early stage non-small cell lung cancer (NSCLC) and patients with low hPAF1C expression levels had significantly better overall survival. Furthermore, the expression of hPAF1C was found to be positively correlated with c-MYC expression in patient tumor samples and in cancer cell lines. Mechanistic studies indicated that hPAF1C could promote lung cancer cell proliferation through regulating c-MYC transcription. These results demonstrated the prognostic value of hPAF1C in early-stage NSCLC and the role of hPAF1C in the transcriptional regulation of c-MYC oncogene during NSCLC tumorigenesis.

Transition of dislocation nucleation induced by local stress concentration in nanotwinned copper

Metals with a high density of nanometre-scale twins have demonstrated simultaneous high strength and good ductility, attributed to the interaction between lattice dislocations and twin boundaries. Maximum strength was observed at a critical twin lamella spacing (∼15 nm) by mechanical testing; hence, an explanation of how twin lamella spacing influences dislocation behaviours is desired. Here, we report a transition of dislocation nucleation from steps on the twin boundaries to twin boundary/grain boundary junctions at a critical twin lamella spacing (12–37 nm), observed with in situ transmission electron microscopy. The local stress concentrations vary significantly with twin lamella spacing, thus resulting in a critical twin lamella spacing (∼18 nm) for the transition of dislocation nucleation. This agrees quantitatively with the mechanical test. These results demonstrate that by quantitatively analysing local stress concentrations, a direct relationship can be resolved between the microscopic dislocation activities and macroscopic mechanical properties of nanotwinned metals.

Metallic materials with a nanometre-scaled lamella structure can have properties that are very different from their coarser-grained counterparts. Here, the authors demonstrate how dislocations in such a material—nanotwinned copper—can nucleate in two distinctly different mechanisms depending on local stress

Deformation-induced structural transition in body-centred cubic molybdenum

Molybdenum is a refractory metal that is stable in a body-centred cubic structure at all temperatures before melting. Plastic deformation via structural transitions has never been reported for pure molybdenum, while transformation coupled with plasticity is well known for many alloys and ceramics. Here we demonstrate a structural transformation accompanied by shear deformation from an original <001>-oriented body-centred cubic structure to a <110>-oriented face-centred cubic lattice, captured at crack tips during the straining of molybdenum inside a transmission electron microscope at room temperature. The face-centred cubic domains then revert into <111>-oriented body-centred cubic domains, equivalent to a lattice rotation of 54.7°, and ~15.4% tensile strain is reached. The face-centred cubic structure appears to be a well-defined metastable state, as evidenced by scanning transmission electron microscopy and nanodiffraction, the Nishiyama–Wassermann and Kurdjumov–Sachs relationships between the face-centred cubic and body-centred cubic structures and molecular dynamics simulations. Our findings reveal a deformation mechanism for elemental metals under high-stress deformation conditions.

Structural phase transitions are known to accommodate plastic deformation in some metals and ceramics. Here, the authors observe the in situ transformation of body-centred cubic molybdenum to face-centred cubic, and finally to body-centred cubic, allowing for 15.4% tensile strain accommodation.

Solitary fibrous tumors of pleura and lung: report of twelve cases

PURPOSE

Solitary fibrous tumors (SFTs) of pleura and lung are rare primary tumors that arise from the submesothelial tissue and usually show a benign clinical course. Immuno-histochemical analysis is used to make the diagnosis. We have reviewed our experience to obtain a better understanding of this disease.

METHODS

In this study, we reviewed 12 patients who had undergone a surgical resection for treatment of benign solitary fibrous tumors (SFTs) of pleura and lung during the period from 2006 to 2012.

RESULTS

Following excision, the most essential characteristic on histopathology was nonatypical spindle-shaped tumor cells on a collagenous background. Keloid-type collagen, hypocellular and hypercellular areas could be observed in all the cases. On immuno-histochemical analysis, we found that mesenchymal markers such as CD34, bcl-2 and vimentin were positive, and S-100 protein and desmin were negative. In addition, Ki-67 was positive in approximately 5% of the tumor cells, but C-kit protein was not detected. If the result for CD34 was negative, expression of bcl-2 was positive. Complete resection was performed through thoracotomy, including 8 cases that involved video-assisted thoracic surgery (VATS). The postoperative courses were uneventful, and there was no recurrence during 3-65 (mean 25) months of follow-up.

CONCLUSIONS

Complete resection of SFTs is usually curative. Morphological and pathological features are important in distinguishing them from other tumors and in predicting clinical behaviour.

Prognostic value of tumor markers, NSE, CA125 and SCC, in operable NSCLC Patients

The aim of this study was to investigate the prognostic value of tumor markers in operable non-small cell lung cancer (NSCLC) patients. A total of 481 NSCLC patients were enrolled in the present study. High levels of neuron-specific enolase (NSE), carbohydrate antigen 125 (CA125) and squamous cell carcinoma antigen (SCC) were detected in 306 (63.6%), 89 (18.5%) and 125 (26.0%) patients, respectively. Seventy-eight of 481 patients died of disease progression, and the median disease-free survival (DFS) and overall survival (OS) were 16.0 and 21.0 months, respectively. The three-year DFS rate was 56.7%, and the OS rate was 75.3%. For serum NSE, the three-year cumulative DFS rate for the normal and elevated group was 67.7% and 51.8% (p = 0.007). The OS in patients with high and normal levels of NSE was 34.0 months and 48.0 months, respectively. The median DFS was 46.0 months versus 32.0 months (p = 0.001), and the OS was 48.0 months versus 44.0 months (p = 0.001) in patients with normal and high levels of CA125. For patients with squamous cell carcinoma, the overall survival was significantly shorter in patients with elevated levels of SCC (p = 0.041). In the multivariate analysis high levels of NSE, CA125 and clinical stage were significantly correlated with worse prognosis (p < 0.05). Patients with all three tumor markers elevated presented the worst prognosis (p < 0.05). In our analysis, high levels of preoperative serum NSE and CA125 are correlated with worse survival in operable NSCLC patients.

Synthesis and Properties of Environmentally Friendly Calcium Phosphate Inhibitor

The purpose of the paper is to provide a non-phosphorus and nitrogen free calcium phosphate inhibitor maleic anhydride-allyloxy polyethoxy carboxylate. The approach is that synthesized monomer allyloxy polyethoxy carboxylate from allyloxy polyethoxy ether and chloracetic acid, and then prepared maleic anhydride-allyloxy polyethoxy carboxylate by free radical polymerization. Structures of allyloxy polyethoxy carboxylate and maleic anhydride-allyloxy polyethoxy carboxylate were characterized through FT-IR and 1H-NMR. Influence of monomer mole ratio in maleic anhydride-allyloxy polyethoxy carboxylate and viscosity-average molecular weight of maleic anhydride-allyloxy polyethoxy carboxylate on its calcium phosphate inhibition performance was discussed. Calcium tolerance and calcium phosphate inhibition capability of maleic anhydride-allyloxy polyethoxy carboxylate was compared with the latest generation of calcium phosphate inhibitor maleic anhydride-ammonium allylpolyethoxy sulphate, and other two kinds of known inhibitor acrylic acid/2-hydroxypropyl acrylate and acrylic acid/acrylamido-2-methyl-1-propane sulfonic acid. As a result, monomer mole ratio and viscosity-average molecular weight has great impact on property of maleic anhydride-allyloxy polyethoxy carboxylate. Calcium tolerance and calcium phosphate inhibition of maleic anhydride-allyloxy polyethoxy carboxylate is similar to maleic anhydride-ammonium allylpolyethoxy sulphate. The results reveal that maleic anhydride-allyloxy polyethoxy carboxylate is an excellent green calcium phosphate inhibitor.

Transformation of LTP gene into Brassica napus to enhance its resistance to Sclerotinia sclerotiorum

Rapeseed (Brassica napus L.) is one of the most important economic crops worldwide, and Sclerotinia sclerotiorum is the most dangerous disease that affects its yield greatly. Lipid transfer protein (LTP) has broad-spectrum anti-bacterial and fungal activities. In this study, B. napus was transformed using Agrobacterium tumefaciens harboring the plasmid-containing LTP gene to study its possible capability of increasing plant's resistance. First, we optimized the petiole genetic transformation system by adjusting the days of explants, bacterial concentrations, ratio of hormones, and cultivating condition. Second, we obtained 8 positive plants by PCR analysis of T0 generation. The PCR results of T1 generation were positive, indicating that the LTP gene had been integrated into B. napus. Third, T1 transgenic plants inoculated by detached leaves with mycelia of S. sclerotiorum showed better disease resistance than non-transformants. Oxalic acid belongs to secondary metabolites of S. sclerotiorum, and several studies have demonstrated that the resistance of rapeseed to oxalic acid is significantly consistent with its resistance to S. sclerotiorum. The result from the seed germination assay showed that when T1 seeds were exposed to oxalic acid stress, their germination rate was evidently higher than that of non-transformant seeds. In addition, we measured some physiological changes in T1 plants and control plants under oxalic acid stress. The results showed that T1 transgenic plants had lower malondialdehyde (MDA) content, higher super oxide dismutase (SOD), and peroxidase (POD) activities than non-transformants, whereas disease resistance was related to low MDA content and high SOD and POD activities.

SU-D-BRB-05: Small Animal Lung Compliance Imaging: Assessment System for Tissue Sensitivity to Radiation Induced Lung Injury

PURPOSE

Recent clinical trials and animal studies have indicated that the tissue sensitivity to radiation induced lung injury (RILI) may be region- specific. In this study, we propose a new 4D cone beam CT (CBCT) basedcompliance imaging method to measure regional pulmonary function change in precisely irradiated small animal under CBCT guidance on small animal radiation research platform (SARRP) to facilitate our understanding of region-specific tissue sensitivity to RILI.

METHODS

Four Sprague-Dawley rats underwent prospective pressure gated 4D CBCT on SARRP. Three animals were selected as control group which underwent a second 4D CBCT scan. The fourth animal was irradiated in the central lung (24 Gy) using 3 × 3 mm collimating cone 2 months prior to the scan. The specific compliance (Csp) was calculated via the real time pressure measurement from the ventilator and displacement field from 3D B-spline image registration between the end of inhale and end of exhale phases from the 4D CBCT scan. The 3D Csp maps from the control animal group were mapped to the irradiated animal as a Csp functional atlas for statistical analysis. We alsoevaluated the repeatability of the Csp measurement on a voxel-by-voxel basis.

RESULTS

No significant Csp difference is found after two month of radiation between the irradiated rat (0.22±0.05) and the functional atlas (0.21±0.07). The observation is consistent with previous publications. The averaged linear correlation coefficient between the voxel-by-voxel Csp measurements from initial and repeat scans in control group is 0.98.

CONCLUSIONS

We proposed a method that uses 4D CBCT based compliance imaging to measure region-specific tissue sensitivity of RILI. We compared the irradiated animal two months after radiation with the control group. Our study shows an excellent robustness of the proposed method for regional lung tissue specific compliance measurement. This work was supported in part by UVa George Amorino Pilot Grant.

SU-E-J-192: Static Breath-Hold MRI Based Measurement of Change in Pulmonary Function Following a Course of Radiation Therapy

PURPOSE

Radiation Therapy (RT) induced pulmonary function change may depend on the location, underlying function of that lung prior to radiations, radiation dose/fractionation and other factors. We propose to evaluate the radiation induced pulmonary function change using static breath-hold MRI scans with vascular information and 3D deformable image registration which can provide pulmonary function relative to RT dose on a regional basis.

METHODS

A MRI scan pair near the end of inhale and near the end of exhale with breath hold were acquired for one lung cancer patient before RT and 6 months after RT. The patient was treated with SBRT with 55 Gy to PTVs in the right and the left lung respectively. B-spline based vesselness preserving image registration algorithm was applied to register the MRI pair for the calculation of local lung expansion as a measurement of regional pulmonary function (PF). The PF maps before RT and after RT were then mapped to the planning CT using the same algorithm tuned for MRI-CT registration. The pulmonary function change was calculated via the PF ratio between two MRI pairs.

RESULTS

Strong spatial correlation was found between the irradiated lung region and the region with greatly decreased PF. Based on dose and PFC distribution, no strong determinant factor was found for PF lost in the left lung while the right lung shows that all the lung tissue receiving dose larger than 28 Gy will have a decreased PF.

CONCLUSIONS

We demonstrated a method that uses static breath-hold MRI based lung imaging to evaluate radiation induced pulmonary function change which can be applied to study the dose and the pulmonary function change in a regional basis. This work is supported by NIH grant support 1R21CA144063.

SU-E-J-82: Improvement in Reproducibility of Lung Expansion Measures with Respiratory Effort Correction

PURPOSE

Longitudinal measurements of pulmonary function must account for subject variation when assessing radiation-induced changes. Previously, we reported intra-subject reproducibility of Jacobian-based measures of lung tissue expansion using repeat 4DCT scans prior to radiation therapy without correcting for differences in respiratory effort. In this study, we present two normalization schemes that correct ventilation images for variations in respiratory effort.

METHODS

Two repeat 4DCT image acquisitions were collected before treatment from seven patients. Using a tissue volume preserving deformable image registration algorithm, two Jacobian ventilation maps were computed from separate acquisitions. Two effort normalization strategies were investigated using intermediated inspiration phases upon the principles of equivalent tidal volume (ETV) and equivalent lung volume (ELV). Additional experiments were performed to verify the effectiveness of the ETV method. Scatter plots of two ventilation maps and statistical parameters of Jacobian ratio were compared before and after each effort correction approach.

RESULTS

The scatter plots of the ventilation maps show improvement in measurement reproducibility using either the ETV or ELV effort correction for all but one case. The one case that did not show improvement had a very similar lung volumes and tidal volumes in the two studies, so effort correction was unnecessary. The coefficient of variation (CV) of Jacobian ratio improved by 21±11 percent (mean±standard deviation) after ETV, and improved by 20±17 percent after ELV. Our experimental results on ETV show the decrease of tidal volume difference in two acquisitions improves reproducibility of lung expansion measures.

CONCLUSIONS

ETV and ELV correction methods improve the reproducibility of pulmonary function measurements in subjects that have differences in respiratory effort in the baseline and followup scans. Additional work is needed to investigate whether ETV or ELV is more effective, and to develop alternate regional normalization schemes that can account for difference in lung expansion rates.

Medium range order of bulk metallic glasses determined by variable resolution fluctuation electron microscopy

Variable resolution fluctuation electron microscopy (FEM) experiments are implemented with hollow-cone dark-field transmission electron microscopy. Medium range order lengths of zirconium and iron based bulk metallic glasses and amorphous silicon nitride are determined from the FEM results. It shows that maximum normalized intensity variances of FEM images occur when their nominal resolution approaches the correlation length Λ of the amorphous materials. Additionally, differences in the length and magnitude of medium range order are compared between metallic and covalent bond amorphous materials.