Effect of retinoic acid on aquaporin 3 expression in keratinocytes

To explore the possible mechanism of the third-generation retinoic acid drugs (isotretinoin, acitretin, adapalene) in inducing skin and mucosa dryness and rhagades; specifically, mechanism by which these drugs influence keratinocyte cell culture models in vitro (HaCaT) and aquaporin channel (AQP3) protein expression was investigated. Isotretinoin, acitretin, and adapalene were applied to human keratinocyte HaCaT cells. Immunohistochemistry, reverse transcriptase polymerase chain reaction, and western blotting were used to detect their effects on AQP3 expression in HaCaT cells at different concentrations (0.000, 0.001, 0.010, 0.060, and 0.100 mg/mL) or different at times (0, 6, 12, 24, and 48 h). At 0.010 mg/mL, maximal AQP3 expression was observed in HaCaT cells; this was significantly higher than the expressions at the other concentrations (P < 0.05). After treatment with isotretinoin, acitretin, or adapalene at 0.010 mg/mL for 12 h, the expression of AQP3 was the highest in the isotretinoin group, followed by the acitretin group, with the lowest expression in the adapalene group. However, the differences were not statistically significant (P > 0.05). Retinoic acid can increase AQP3 expression in HaCaT cells, with significant effects observed with 0.010 mg/mL isotretinoin treatment for 12 h. The side effects, namely skin and mucosa dryness caused by retinoic acid might be related to its effects on AQP3 expression.

Abstract P3-01-13: Risk factors of non-sentinel lymph node metastasis in breast cancer patients with metastatic sentinel lymph node

Objective To study the factors influencing the non-sentinel lymph node(NSLN) status and to assess Memorial Sloan-Kettering Cancer Center (MSKCC) nomogram performance in predicting SLN metastases in a sentinel lymph node(SLN) positive Chinese breast cancer population. Methods Data were collected from breast cancer patients who were diagnosed with pathological positive sentinel lymph node and received further axillary lymph node dissection(ALND) in Shanghai Ruijin Hospital from January 2011 to August 2014. Use MSKCC nomogram to calculate each patient's NSLN metastasis risk score. The receiver operator characteristic curve(ROC curve)and the area under the ROC curve(AUC)was used to assess the predictive accuracy of the model. Results Among the 1147 patients who received sentinel biopsy in our center, 150 SLN positive patients who received ALND were enrolled in this study. By univariate analysis, multifocal breast cancer (P = 0.017), SLN+/SLN ratio (P = 0.010) and axillary lymphadenopathy displayed by ultrasound(P = 0.005) are the influencing factors of NSLN metastases. By multivariate analysis, multifocal breast cancer (OR 7.25, 95% CI 1.73∼30.43, P = 0.007), SLN+/SLN ratio≥0.5 (OR 2.564, 95% CI 1.22∼5.39, P = 0.013) and axillary lymphadenopathy displayed by ultrasound (OR 2.471, 95% CI 1.18∼5.19, P = 0.017) are the independent influencing factors of NSLN metastases. The AUC of MSKCC nomogram in this population is 0.677. Conclusion For breast cancer patients with positive sentinel lymph node, multifocality, SLN+/SLN ratio and axillary lymphadenopathy displayed by ultrasound is related to NSLN metastasis. MSKCC has low accuracy in predicting NSLN status of this population.

Citation Format: Huang J, Chen X, Shen K, Li Y, Chen W, He J, Zhu L, Huang O, Zong Y, Fei X, Jin X. Risk factors of non-sentinel lymph node metastasis in breast cancer patients with metastatic sentinel lymph node. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P3-01-13.

Abstract P6-04-04: Comprehensive transcriptome analysis identifies novel molecular subtypes and subtype-specific lncRNAs of triple-negative breast cancer

Background: Triple-negative breast cancer (TNBC) is a highly heterogeneous group of cancers with no effective therapeutic targets hitherto. Thus molecular subtyping is necessary to better identify molecular-based therapies. While some classifiers have been established, no one has integrated the expression profiles of long-noncoding RNAs (lncRNAs) into such subtyping criterions. Considering the emerging important role of lncRNAs in gene regulation and other cellular processes, a novel classification integrating the transcriptome profiles of both messenger RNA (mRNA) and lncRNA would help us better understand the heterogeneity of TNBC and treat patients accordingly.

Methods: Using human transcriptome microarray, we retrieved the transcriptome profiles of 165 consecutive TNBC samples. We used k-means clustering to classify the samples based on the most differentially expressed genes (standard deviation&gt;0.65). Empirical cumulative distribution function was analyzed to determine the optimal number of subtypes. Then the new classifier was compared with the Lehmann/Pietenpol system, and survival analyses were performed to compare the recurrence-free survival (RFS) in different subtypes. Gene Ontology (GO) and pathway analyses were applied to determine the main function of the subtype-specific genes and pathways. We conducted co-expression network analysis to identify interactions between lncRNAs and mRNAs, and to predict possible functions of subtype specific lncRNAs.

Results: All 165 TNBC tumors were classified into four distinct clusters, each displaying unique GOs and pathways. These include an immunomodulatory (IM) subtype, a luminal androgen receptor (LAR) subtype, a mesenchymal-like (MES) subtype and a basal-like and immune suppressed (BLIS) subtype, accounting for 17.0%, 17.6%, 33.3%, and 32.2% of the patients, respectively. The IM subtype had unique GOs and pathways involving immune cell process. The LAR subtype was highly enriched in hormonally regulated pathways. Enriched pathways in the MES subtype included ECM-receptor interaction, focal adhesion, and processes linked to growth factor signaling pathways. The BLIS subtype was characterized by downregulation of immune response gene and activation of cell cycle and DNA repair, and patients in this subtype experienced worse RFS compared to other subtypes (log-rank test,P=0.045), which was in concordance with the highly proliferative and immune-suppressed nature of these tumors. When analyzing the distribution of the Lehmann/Pietenpol subtypes in our classification system, we found that the two classification systems were significantly correlated (P=0.039). However, our novel classification was more concise and significantly connected with survival outcome. Subtype-specific lncRNAs were identified and their possible functions were predicted using co-expression network analysis.

Conclusions: We developed a novel TNBC classification system integrating the expression profiles of both mRNAs and lncRNAs, and determined subtype-specific lncRNAs that are potential biomarkers and targets of TNBC. If further validated in larger population, our novel classification system could facilitate patient counseling and individualize treatment of TNBC.

Citation Format: Liu Y-R, Jiang Y-Z, Xu X-E, Zuo W-J, Yu K-D, Jin X, Hu X, Wu J, Liu G-Y, Di G-H, Shao Z-M. Comprehensive transcriptome analysis identifies novel molecular subtypes and subtype-specific lncRNAs of triple-negative breast cancer. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P6-04-04.

The anterior and posterior pedunculopontine tegmental nucleus are involved in behavior and neuronal activity of the cuneiform and entopeduncular nuclei

Loss of cholinergic neurons in the mesencephalic locomotor region, comprising the pedunculopontine nucleus (PPN) and the cuneiform nucleus (CnF), is related to gait disturbances in late stage Parkinson's disease (PD). We investigate the effect of anterior or posterior cholinergic lesions of the PPN on gait-related motor behavior, and on neuronal network activity of the PPN area and basal ganglia (BG) motor loop in rats. Anterior PPN lesions, posterior PPN lesions or sham lesions were induced by stereotaxic microinjection of the cholinergic toxin AF64-A or vehicle in male Sprague-Dawley rats. First, locomotor activity (open field), postural disturbances (Rotarod) and gait asymmetry (treadmill test) were assessed. Thereafter, single-unit and oscillatory activities were measured in the non-lesioned area of the PPN, the CnF and the entopeduncular nucleus (EPN), the BG output region, with microelectrodes under urethane anesthesia. Additionally, ECoG was recorded in the motor cortex. Injection of AF64-A into the anterior and posterior PPN decreased cholinergic cell counts as compared to naive controls (P<0.001) but also destroyed non-cholinergic cells. Only anterior PPN lesions decreased the front limb swing time of gait in the treadmill test, while not affecting other gait-related parameters tested. Main electrophysiological findings were that anterior PPN lesions increased the firing activity in the CnF (P<0.001). Further, lesions of either PPN region decreased the coherence of alpha (8-12 Hz) band between CnF and motor cortex (MCx), and increased the beta (12-30 Hz) oscillatory synchronization between EPN and the MCx. Lesions of the PPN in rats had complex effects on oscillatory neuronal activity of the CnF and the BG network, which may contribute to the understanding of the pathophysiology of gait disturbance in PD.

Isobavachalcone induces the apoptosis of gastric cancer cells via inhibition of the Akt and Erk pathways

In the present study, the MGC803 gastric cancer cell line was used as an experimental model to evaluate the potential role of isobavachalcone (IBC) in cell apoptosis, migration and invasion. The inhibitory effects of IBC on cell proliferation were determined using a methylthiazolyltetrazolium assay. Cellular morphological changes were assessed using Wright-Giemsa staining, and cell apoptosis was evaluated by flow cytometric analysis. The results of the present study demonstrated that IBC inhibited the proliferation of MGC803 cells in a concentration- and time-dependent manner. Furthermore, the wound healing and Matrigel™ Transwell® invasion assays demonstrated that IBC decreased cell migration and invasion in a concentration-dependent manner. Western blotting was used to determine the protein expression levels of caspase-3, B-cell lymphoma-2 (Bcl-2) and Bcl-2-associated X protein (Bax), as well as the key protein kinases in the Akt and extracellular signal-regulated kinase (Erk) signaling pathways. During the IBC-induced apoptosis of MGC803 cells, transient activation of phosphorylated (p)-Akt and p-Erk inhibited the activation of Akt and Erk, upregulated Bax expression, downregulated Bcl-2 expression and activated caspase-3. These results suggest that IBC inhibited the growth of MGC803 gastric cancer cells by regulating the protein expression of caspase-3, Bcl-2 and Bax. In addition, inhibition of the Akt and Erk signaling pathways may be important mechanisms underlying the IBC-induced apoptosis of gastric cancer cells.

Cytochrome c oxidase subunit VIIb as a potential target in familial hypercholesterolemia by bioinformatical analysis

OBJECTIVE

The aim of the study is to explore the potential familial hypercholesterolemia markers by comparing with healthy controls.

MATERIAL AND METHODS

We downloaded the gene expression profile GSE13985 from Gene Expression Omnibus database including five patients diagnosed with familial hypercholesterolemia (FH) and five age, sex, status matched controls. We applied t-test, Wilcox test and Fisher test in Multtest package of R language to identify the differentially expressed genes (DEGs) with p < 0.05 and |logFC| > 1, and constructed the interaction network of the top 3 up- and down-regulated genes using STRING. Besides, the modules of network were analyzed with Cytoscape and screened out with Mcode plugin, and the functional annotation of the genes involved in the modules was analyzed with BiNGO (Biological Networks Gene Ontology).

RESULTS

Firstly, totally 101 differentially expressed genes were identified in FH samples compared with control samples, the genes ranked in top 3 up- and down-regulated genes were selected. Then, basing on the interaction network of these selected genes, ribosomal L24 domain containing 1 (RSL24D1) and cytochrome c oxidase subunit VIIb (COX7B) showed a central position in the interaction network, and also exited in the modules of the network. The functional annotation of the genes in modules showed that COX7B was associated with oxidative phosphorylation.

CONCLUSIONS

COX7B might play vital roles in FH via oxidative phosphorylation system, and might be potential target in the treatment of FH.

Microarray based analysis of gene expression patterns in pancreatic neuroendocrine tumors

OBJECTIVE

Pancreatic neuroendocrine tumors (PanNETs) are a small subgroup of tumors with a variety of biological behaviors.

MATERIALS AND METHODS

We sought to identify the specially expressed genes and characterize significant pathways in PanNETs compared with non-neoplastic samples. Gene expression profile GSE43795 was obtained from Gene Expression Omnibus database, which included 6 PanNETs and 5 non-neoplastic samples. The differentially expressed genes (DEGs) were identified using Limma package. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses were used to enrich the functions and pathways of DEGs. Transcription factors (TFs) and tumor-associated genes (TAGs) were also identified. Finally, a protein-protein interaction (PPI) network was constructed, and hub proteins and functional module were screened out.

RESULTS

Total of 821 DEGs (421 down-regulated, 400 up-regulated) were selected. GO and KEGG enrichment analyses showed that up-regulated DEGs were related to several pathways, including type 2 diabetes mellitus, Ca2+ signaling pathway, long-term potentiation, and long-term depression pathways. Down-regulated DEGs were enriched in several pathways, such as pancreatic secretion, protein digestion and absorption, and metabolic pathway. Interferon-stimulated gene protein 15 (ISG15), somatostatin (SST), and synaptosomal-associated protein 25 kDa (SNAP25) were identified as hub proteins.

CONCLUSIONS

The genes involved in type 2 diabetes mellitus pathway may play important roles in the development of PanNETs. SNAP25, SST, and ISG15 may be used as potential targets for treatment of PanNETs.

Association of patellar bone marrow lesions with knee pain, patellar cartilage defect and patellar cartilage volume loss in older adults: a cohort study

AIM

To examine the cross-sectional and longitudinal associations of patellar bone marrow lesion (BMLs) with knee pain, cartilage defects and cartilage volume in older adults.

METHODS

A total of 904 randomly selected subjects (mean 62.4 years, 49.9% female) were studied. Fat suppressed T1-weighted spoiled gradient recall and T2-weighted fast spin echo magnetic resonance imaging (MRI) sequences were used to assess cartilage volume, cartilage defects and/or BMLs at baseline (n = 904) and 2.6 (range: 1.4-4.8) years' follow-up (n = 414). Knee pain was assessed by self-administered Western Ontario McMaster Osteoarthritis Index (WOMAC) questionnaire at baseline (n = 904) and follow-up (n = 790).

RESULTS

The prevalence of any patellar BMLs was 19% and was higher in those with tibiofemoral BMLs. In multivariable analyses, patellar BMLs were positively associated with any knee pain at baseline and an increase in knee pain when going up/down stairs (odds ratio (OR): 1.67, 95% confidence interval (CI): 1.08, 2.59) but not with other knee pain subscales. Patella BMLs were also associated with patellar cartilage defects both at baseline and change over time (OR: 1.76, 95% CI: 1.00, 3.70) but not tibiofemoral defects. Patellar BMLs were negatively associated with baseline and change in patella cartilage volume (β: -2.10%, 95% CI: -3.39%, -0.80%). These associations remained significant after further adjustment for tibiofemoral BMLs.

CONCLUSIONS

Patellar BMLs were consistently associated with increased knee pain especially going up/down stairs, increased patellar cartilage defects, and decreased patellar cartilage volume cross-sectionally and longitudinally, suggesting a predominantly compartment specific role for patellar BMLs.

[Epidemiologic characteristics and the relationship with disease severity of respiratory syncytial virus genotypes from children with lower respiratory tract infection in the southern Zhejiang province]

OBJECTIVE

To investigate the epidemiological characteristics of respiratory syncytial virus (RSV) subtypes and genotypes in southern Zhejiang province, and to determine whether RSV genotypes are correlated with the disease severity of lower respiratory tract infection (LRTI).

METHOD

Nasopharyngeal secretions (NPS) from children under 5 years of age who were hospitalized with LRTI during 5 consecutive seasons from July 1, 2009 to June 30, 2014 were collected. RSV antigen was determined using direct immunofluorescence (DIF). Two hundred strains of RSV were randomly selected from each epidemic season. RNA was extracted and identified as subtype A or B by using reverse transcription-polymerase chain reaction (RT-PCR), and randomly selected strains of the full length attachment (G) genes of both subtype A and subtype B were amplified by PCR and sequencing. Clinical data were collected, and the disease severity between different genotypes were compared simultaneously.

RESULT

Of the total 1 000 randomly selected RSV positive samples, 462 (46.2%) and 538 (53.8%) samples were identified as subtype A and B, respectively. It was found that subtype B predominated in the 2009-2010 and 2012-2014 epidemic seasons and subtype A in 2010-2012 epidemic seasons. A total of 112 strains of complete sequences of G genes were obtained, including four subtype A genotypes NA1, NA4, GA2 and ON1, and six subtype B genotypes BA8-10, BA-C, CB1, and GB2. Phylogenetic analysis revealed that 39/52 (75.0%) subtype A strains were classified as NA1 genotype, followed by ON1 genotype (10/52,19.2%) and 44/60 (73.3%) subtype B strains were classified as BA9 genotype, followed by BA8 genotype (6/60,10.0%). BA9 was the predominant genotype among subtype B except 2010-2011 epidemic season, while NA1 was the predominant genotype among subtype A except 2013-2014 epidemic season. Only ON1 and BA9 genotypes were checked out during 2013-2014 epidemic season. There was statistically significant difference in the average severity score of illness in 39 cases infected with NA1 genotype (4.154) and 44 cases of BA9 genotype (3.341) (U=642.500, P<0.05). Furthermore, in the rate of oxygen uptake, the percentage of those infected with NA1 genotype (33.3%) was higher than those infected with BA9 genotype (13.6%) (χ2=4.544, P<0.05). However, there were no significant difference in the age, clinical symptoms, the percentage of intensive care unit admission, length of hospitalization and the outcome of the disease between NA1 and BA9 infection.

CONCLUSION

The shift of predominant RSV subtype from 2009 to 2014 were B-A-A-B-B in the southern areas of Zhejiang province. Multiple genotypes co-circulated during five RSV epidemic seasons. NA1 and BA9 genotypes were the predominant genotypes of subtype A and B, respectively. Compared with infection with BA9 genotype, NA1 genotype infection was associated with more severe disease and proportion of patients needed oxygen therapy was higher.

Surgical management of retinal detachment resulting from macular hole in a setting of high myopia

PURPOSE

To evaluate the anatomical and visual outcomes of pars plana vitrectomy (PPV) with internal limiting membrane (ILM) peeling and use of retinal tamponade for retinal detachments resulting from macular hole (MHRD) in highly myopic eyes.

METHODS

Twenty-nine highly myopic patients (29 eyes) underwent PPV with ILM peeling and retinal tamponade for MHRD were enrolled. Demographics and best-corrected visual acuity (BCVA) were measured preoperatively and at final follow-up. Anatomical success and macular hole closure were analyzed.

RESULTS

Patients' mean age of patients was 58.7 ± 10.6 years, mean follow-up was 11.7 ± 7.4 months. Twenty three eyes (23/26, 88.5%) undergoing primary PPV combined with ILM peeling had successful initial retinal reattachment, including 19 eyes (19/19, 100%) with silicone oil tamponade and in 4 eyes (4/7, 57.1%) with sulfur hexafluoride (C3F8) tamponade. Overall anatomical success was achieved in 27 eyes (27/29, 93.1%). The macular hole closure was observed in 17 eyes (17/26, 65.4%) with final anatomical success. Compared to preoperative BCVA, the mean postoperative BCVA in the eyes with anatomical success was significantly improved (P = 0.007, Wilcoxon signed rank test).

CONCLUSION

As a primary or secondary procedure, PPV combined with ILM peeling and usage of retinal tamponade serves as an effective method for MHRD in highly myopic eyes.

Precision Measurement of the p(e,e^{'}p)π^{0} Reaction at Threshold

New results are reported from a measurement of π^{0} electroproduction near threshold using the p(e,e^{'}p)π^{0} reaction. The experiment was designed to determine precisely the energy dependence of s- and p-wave electromagnetic multipoles as a stringent test of the predictions of chiral perturbation theory (ChPT). The data were taken with an electron beam energy of 1192 MeV using a two-spectrometer setup in Hall A at Jefferson Lab. For the first time, complete coverage of the ϕ_{π}^{*} and θ_{π}^{*} angles in the pπ^{0} center of mass was obtained for invariant energies above threshold from 0.5 up to 15 MeV. The 4-momentum transfer Q^{2} coverage ranges from 0.05 to 0.155 (GeV/c)^{2} in fine steps. A simple phenomenological analysis of our data shows strong disagreement with p-wave predictions from ChPT for Q^{2}>0.07 (GeV/c)^{2}, while the s-wave predictions are in reasonable agreement.

The preliminary application of assessment system for cancer pain management

OBJECTIVE

To apply the assessment system for cancer pain management preliminarily, explore the issues in cancer pain diagnosis and treatment, and analyze the differences between oncology department and non-oncology in cancer pain diagnosis and treatment.

PATIENTS AND METHODS

The validated questionnaires were collected from department of medical oncology of three hospitals including Xuzhou Central Hospital. Subjects included 41 doctors, 43 nurses, 50 patients, and 12 wards. The data was analyzed to find the main issues as far in cancer pain management. Twelve units of oncology department and 15 units of non-oncology in three hospitals including Xuzhou Central Hospital were assessed with assessment system for cancer pain management. Rank test was conducted to analyze the differences in cancer pain diagnosis and treatment between oncology department and non-oncology.

RESULTS

The average scores of doctors, nurses, wards were 85.4, 88.5, 83.8, respectively, while the average score of patients was 68.7. The percentile of analgesic efficacy and safety in patients was 81.7 and the percentile of analgesic opinion changes was only 55.8, indicating that it was necessary to enhance the education of concept about pain management. The average scores of assessment were 82.2 ± 2.1 and 39.9 ± 3.6 for oncology and non-oncology, respectively. The Wilcoxon value of Rank test was 120.0, indicating the significant difference between the two (p < 0.01). It suggests that there is still a great shortage in cancer pain diagnosis and treatment in non-oncology, and there is an urgent need to further strengthen the cancer pain management-related continuing education.

CONCLUSIONS

In cancer pain treatment-related clinical work, patients' pain education still needs to be strengthened; in comparison with oncology, the cancer pain management-related continuing education for non-oncology also needs to be strengthened.

The LIM-only transcription factor LMO2 determines tumorigenic and angiogenic traits in glioma stem cells

Glioblastomas (GBMs) maintain their cellular heterogeneity with glioma stem cells (GSCs) producing a variety of tumor cell types. Here we interrogated the oncogenic roles of Lim domain only 2 (LMO2) in GBM and GSCs in mice and human. High expression of LMO2 was found in human patient-derived GSCs compared with the differentiated progeny cells. LMO2 is required for GSC proliferation both in vitro and in vivo, as shRNA-mediated LMO2 silencing attenuated tumor growth derived from human GSCs. Further, LMO2 is sufficient to induce stem cell characteristics (stemness) in mouse premalignant astrocytes, as forced LMO2 expression facilitated in vitro and in vivo growth of astrocytes derived from Ink4a/Arf null mice and acquisition of GSC phenotypes. A subset of mouse and human GSCs converted into vascular endothelial-like tumor cells both in vitro and in vivo, which phenotype was attenuated by LMO2 silencing and promoted by LMO2 overexpression. Mechanistically, the action of LMO2 for induction of glioma stemness is mediated by transcriptional regulation of Jagged1 resulting in activation of the Notch pathway, whereas LMO2 directly occupies the promoter regions of the VE-cadherin gene for a gain of endothelial cellular phenotype. Subsequently, selective ablation of human GSC-derived VE-cadherin-expressing cells attenuated vascular formation in mouse intracranial tumors, thereby significantly prolonging mouse survival. Clinically, LMO2 expression was elevated in GBM tissues and inversely correlated with prognosis of GBM patients. Taken together, our findings describe novel dual roles of LMO2 to induce tumorigenesis and angiogenesis, and provide potential therapeutic targets in GBMs.

Applications of the line-of-response probability density function resolution model in PET list mode reconstruction

Resolution degradation in PET image reconstruction can be caused by inaccurate modeling of the physical factors in the acquisition process. Resolution modeling (RM) is a common technique that takes into account the resolution degrading factors in the system matrix. Our previous work has introduced a probability density function (PDF) method of deriving the resolution kernels from Monte Carlo simulation and parameterizing the LORs to reduce the number of kernels needed for image reconstruction. In addition, LOR-PDF allows different PDFs to be applied to LORs from different crystal layer pairs of the HRRT. In this study, a thorough test was performed with this new model (LOR-PDF) applied to two PET scanners-the HRRT and Focus-220. A more uniform resolution distribution was observed in point source reconstructions by replacing the spatially-invariant kernels with the spatially-variant LOR-PDF. Specifically, from the center to the edge of radial field of view (FOV) of the HRRT, the measured in-plane FWHMs of point sources in a warm background varied slightly from 1.7 mm to 1.9 mm in LOR-PDF reconstructions. In Minihot and contrast phantom reconstructions, LOR-PDF resulted in up to 9% higher contrast at any given noise level than image-space resolution model. LOR-PDF also has the advantage in performing crystal-layer-dependent resolution modeling. The contrast improvement by using LOR-PDF was verified statistically by replicate reconstructions. In addition, [(11)C]AFM rats imaged on the HRRT and [(11)C]PHNO rats imaged on the Focus-220 were utilized to demonstrated the advantage of the new model. Higher contrast between high-uptake regions of only a few millimeter diameter and the background was observed in LOR-PDF reconstruction than in other methods.

Correlation between gamma index passing rate and clinical dosimetric difference for pre-treatment 2D and 3D volumetric modulated arc therapy dosimetric verification

OBJECTIVE

To investigate comparatively the percentage gamma passing rate (%GP) of two-dimensional (2D) and three-dimensional (3D) pre-treatment volumetric modulated arc therapy (VMAT) dosimetric verification and their correlation and sensitivity with percentage dosimetric errors (%DE).

METHODS

%GP of 2D and 3D pre-treatment VMAT quality assurance (QA) with different acceptance criteria was obtained by ArcCHECK® (Sun Nuclear Corporation, Melbourne, FL) for 20 patients with nasopharyngeal cancer (NPC) and 20 patients with oesophageal cancer. %DE were calculated from planned dose-volume histogram (DVH) and patients' predicted DVH calculated by 3DVH® software (Sun Nuclear Corporation). Correlation and sensitivity between %GP and %DE were investigated using Pearson's correlation coefficient (r) and receiver operating characteristics (ROCs).

RESULTS

Relatively higher %DE on some DVH-based metrics were observed for both patients with NPC and oesophageal cancer. Except for 2%/2 mm criterion, the average %GPs for all patients undergoing VMAT were acceptable with average rates of 97.11% ± 1.54% and 97.39% ± 1.37% for 2D and 3D 3%/3 mm criteria, respectively. The number of correlations for 3D was higher than that for 2D (21 vs 8). However, the general correlation was still poor for all the analysed metrics (9 out of 26 for 3D 3%/3 mm criterion). The average area under the curve (AUC) of ROCs was 0.66 ± 0.12 and 0.71 ± 0.21 for 2D and 3D evaluations, respectively.

CONCLUSIONS

There is a lack of correlation between %GP and %DE for both 2D and 3D pre-treatment VMAT dosimetric evaluation. DVH-based dose metrics evaluation obtained from 3DVH will provide more useful analysis.

ADVANCES IN KNOWLEDGE

Correlation and sensitivity of %GP with %DE for VMAT QA were studied for the first time.

Operation of a 400MHz NMR magnet using a (RE:Rare Earth)Ba2Cu3O7-x high-temperature superconducting coil: Towards an ultra-compact super-high field NMR spectrometer operated beyond 1GHz

High-temperature superconductors (HTS) are the key technology to achieve super-high magnetic field nuclear magnetic resonance (NMR) spectrometers with an operating frequency far beyond 1GHz (23.5T). (RE)Ba₂Cu₃O_7-x (REBCO, RE: rare earth) conductors have an advantage over Bi₂Sr₂Ca₂Cu₃O_10-x (Bi-2223) and Bi₂Sr₂CaCu₂O_8-x (Bi-2212) conductors in that they have very high tensile strengths and tolerate strong electromagnetic hoop stress, thereby having the potential to act as an ultra-compact super-high field NMR magnet. As a first step, we developed the world's first NMR magnet comprising an inner REBCO coil and outer low-temperature superconducting (LTS) coils. The magnet was successfully charged without degradation and mainly operated at 400MHz (9.39T). Technical problems for the NMR magnet due to screening current in the REBCO coil were clarified and solved as follows: (i) A remarkable temporal drift of the central magnetic field was suppressed by a current sweep reversal method utilizing ∼10% of the peak current. (ii) A Z2 field error harmonic of the main coil cannot be compensated by an outer correction coil and therefore an additional ferromagnetic shim was used. (iii) Large tesseral harmonics emerged that could not be corrected by cryoshim coils. Due to those harmonics, the resolution and sensitivity of NMR spectra are ten-fold lower than those for a conventional LTS NMR magnet. As a result, a HSQC spectrum could be achieved for a protein sample, while a NOESY spectrum could not be obtained. An ultra-compact 1.2GHz NMR magnet could be realized if we effectively take advantage of REBCO conductors, although this will require further research to suppress the effect of the screening current.

Metastasis mechanism and gene/protein expression in gastric cancer with distant organs metastasis

Metastasis is the most fatal characteristics of malignancy tumor, which accounted for more than 90% of tumor-related mortality. Distant organ or tissue metastasis is a sign of poor prognosis in patients with gastric cancer. Tumor cells metastasis is a very complex process including tumor cell transformation, growth, angiogenesis, invasion, dissemination and survival in the circulation, and subsequent adhesion and colonization the secondary organ or tissue. The origin of tumor cell, genetic variation, the circulatory mode and the physiological structure of the metastatic organ determines the specific sites of distant metastasis. In theory, the metastatic lesion is originated from their primary tumor, so they should have the same molecular profile with the primary tumor. But this view has been confirmed to be wrong in various tumors, including gastric cancer. The gene expression of primary gastric cancer and its metastasis have differences, which may contribute to the early diagnosis and individualized treatment of metastasis. However, the heterogeneity of tumor cells is still unclear in different metastasis lesion of gastric cancer, which will be a major focus of future research. In this review, we discuss the basic principles of cancer metastasis, the unique physiological characteristics of the various metastasis organs and the expression of different functions of gene/protein in primary and metastasis of gastric cancer. In addition, we also discuss the diagnosis, prognosis and treatment in various organ metastasis of gastric cancer.

Mass effect and signal intensity alteration in the suprapatellar fat pad: associations with knee symptoms and structure

OBJECTIVE

To describe cross-sectional associations between mass effect or signal intensity alteration of the suprapatellar fat pad (SPFP) with knee symptoms and structure in older adults.

METHODS

A cross-sectional sample of 904 randomly selected subjects (mean 62.4 years, 49.9% female) was studied. T1- or T2-weighted fat suppressed magnetic resonance imaging (MRI) was used to assess mass effect or signal intensity alteration of SPFP, cartilage volume, cartilage defects, and bone marrow lesions (BMLs). Knee pain was assessed by self-administered Western Ontario McMaster Osteoarthritis Index (WOMAC) questionnaire. The Osteoarthritis Research Society International (OARSI) atlas was used to assess knee osteophyte, joint space narrowing (JSN) and radiographic osteoarthritis (ROA). Univariable and multivariable linear or logistic regression analyses were used to examine the associations.

RESULTS

After adjustment for confounders including age, sex, body mass index (BMI), disease status, tibial bone area and/or ROA, the presence of SPFP mass effect was significantly associated with any knee pain (OR: 2.39; 95% confidence interval (CI): 1.54, 3.70) and ROA (OR: 2.10; 95% CI: 1.33, 3.31) but not with cartilage volume, cartilage defects or BMLs. The presence of SPFP signal intensity alteration was significantly associated with any knee pain (OR: 1.90; 95% CI: 1.43, 2.53), ROA (OR: 1.83; 95% CI: 1.37, 2.45), any BMLs (OR: 1.55; 95% CI: 1.17, 2.06) but not with cartilage volume and cartilage defects. Significant associations with knee pain and BMLs were more evident in subjects with ROA. Presence of SPFP mass effect and/or signal intensity alteration combined was associated with any tibial cartilage defects (OR: 1.45; 95% CI: 1.04, 2.04).

CONCLUSIONS

SPFP mass effect and/or signal intensity alterations are deleteriously associated with knee pain, radiographic OA and BMLs in this cross-sectional study, suggesting that SPFP abnormalities may contribute to pain and structural abnormalities in the knee.

Perampanel, an antagonist of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors, for the treatment of epilepsy: studies in human epileptic brain and nonepileptic brain and in rodent models

Perampanel [Fycompa, 2-(2-oxo-1-phenyl-5-pyridin-2-yl-1,2-dihydropyridin-3-yl)benzonitrile hydrate 4:3; Eisai Inc., Woodcliff Lake, NJ] is an AMPA (α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid) receptor antagonist used as an adjunctive treatment of partial-onset seizures. We asked whether perampanel has AMPA receptor antagonist activity in both the cerebral cortex and hippocampus associated with antiepileptic efficacy and also in the cerebellum associated with motor side effects in rodent and human brains. We also asked whether epileptic or nonepileptic human cortex is similarly responsive to AMPA receptor antagonism by perampanel. In rodent models, perampanel decreased epileptic-like activity in multiple seizure models. However, doses of perampanel that had anticonvulsant effects were within the same range as those engendering motor side effects. Perampanel inhibited native rat and human AMPA receptors from the hippocampus as well as the cerebellum that were reconstituted into Xenopus oocytes. In addition, with the same technique, we found that perampanel inhibited AMPA receptors from hippocampal tissue that had been removed from a patient who underwent surgical resection for refractory epilepsy. Perampanel inhibited AMPA receptor-mediated ion currents from all the tissues investigated with similar potency (IC50 values ranging from 2.6 to 7.0 μM). Cortical slices from the left temporal lobe derived from the same patient were studied in a 60-microelectrode array. Large field potentials were evoked on at least 45 channels of the array, and 10 μM perampanel decreased their amplitude and firing rate. Perampanel also produced a 33% reduction in the branching parameter, demonstrating the effects of perampanel at the network level. These data suggest that perampanel blocks AMPA receptors globally across the brain to account for both its antiepileptic and side-effect profile in rodents and epileptic patients.

The correlation between MR diffusion-weighted imaging and pathological grades on glioma

OBJECTIVE

This work intends to quantitatively analyze on pathological grade of glioma using Magnetic Resonance (MR) diffusion weighted imaging (DWI) and exploring the relativity of pathological grade and Apparent Diffusion Coefficient (ADC) value of MR diffusion weighted imaging.

PATIENTS AND METHODS

40 patients with glioma accepted the MR diffusion weighted imaging to measure the ADC value of tumor with 3.0T MR machine before the surgery. Tumor samples were sent for pathologic diagnosis and tumor cell density measurement after the operation. The acquired data were analyzed statistically.

RESULTS

The ADC values of low-grade (WHO I-II) glioma were higher than that of high-grade (WHO III-IV), but the cell density of low-grade glioma was apparently lower than that of high-grade glioma. The ADC values and density of tumor cells were negatively correlated with WHO malignant grades, while the density of cells of glioma was positively correlated with WHO malignant grades.

CONCLUSIONS

MR diffusion weighted imaging is an objective and effective examination method.

Controlling the nanoscale rippling of graphene with SiO2 nanoparticles

The electronic properties of graphene can be significantly influenced by mechanical strain. One practical approach to induce strain in graphene is to transfer atomically thin membranes onto pre-patterned substrates with specific corrugations. The possibility of using nanoparticles to impart extrinsic rippling to graphene has not been fully explored yet. Here we study the structure and elastic properties of graphene grown by chemical vapour deposition and transferred onto a continuous layer of SiO2 nanoparticles with diameters of around 25 nm, prepared on a Si substrate by the Langmuir-Blodgett technique. We show that the corrugation of the transferred graphene, and thus the membrane strain, can be modified by annealing at moderate temperatures. The membrane parts bridging the nanoparticles are suspended and can be reversibly lifted by the attractive forces between an atomic force microscope tip and graphene. This allows the dynamic control of the local morphology of graphene nanomembranes.