Application of a Novel Ultra-High Resolution Multi-Detector CT in Quantitative Imaging of Trabecular Microstructure

PURPOSE

To evaluate the performance of a novel ultra-high resolution multi-detector CT scanner (Canon Aquilion Precision UHR CT), capable of visualizing ~150 μm details, in quantitative assessment of bone microarchitecture. Compared to conventional CT, the spatial resolution of UHR CT begins to approach the size of the trabeculae. This might enable measurements of microstructural correlates of osteoporosis, osteoarthritis, and other bone disease.

METHODS

The UHR CT system features a 160-row x-ray detector with 250×250 μm pixels (measured at isocenter) and a custom-designed x-ray source with a 0.4×0.5 mm focal spot. Visualization of high contrast details down to ~150 μm has been achieved on this device, which is now commercially available for clinical use. To evaluate the performance of UHR CT in quantification of bone microstructure, we imaged a variety of human bone samples (including ulna, radius, and vertebrae) embedded in a ~16 cm diameter plastic cylinder and in an anthropomorphic thorax phantom (QRM-Thorax, QRM Gmbh). Helical UHR CT acquisitions (120 kVp tube voltage) were acquired at scan exposures of 375 mAs - 5 mAs. For comparison, the samples were also imaged using a Normal Resolution (NR) mode available on the scanner, involving 500 μm slice thickness, exposure of 50 mAs, and a focal spot of 0.6×1.3 mm. We obtained micro-CT (μCT) of the bone samples at ~28 μm voxel size as a gold-standard reference. Geometric measurements of bone microstructure were performed in 17 regions-of-interests (ROIs) distributed throughout the bones of the phantoms; image registration was used to place the ROIs at corresponding locations in the UHR CT and NR CT. Trabecular thickness Tb.Th, spacing Tb.Sp, and Bone Volume fraction BvTv were obtained. The UHR and NR imaging protocols were compared terms of correlations to μCT and error of trabecular measurements. The effect of dose on trabecular morphometry was also studied for the UHR CT. Furthermore, we evaluated the sensitivity of texture features of trabecular bone (recently proposed as an alternative to geometric indices of microstructure) to imaging protocol. Image texture evaluation was performed using ~150 regions of interest (ROIs) across all bone samples. Three-dimensional Gray Level Co-occurrence Matrix (GLCM) and Gray Level Run Length Matrix (GLRM) features were extracted for each ROI. We analyzed correlation and concordance correlation coefficient (CCC) of the mean ROI values of texture features obtained using the UHR and NR modes.

RESULTS

UHR CT reconstructions of bone samples clearly demonstrated improved visualization of the trabeculae compared to NR CT. UHR CT achieved substantially better correlations for all three metrics of bone microstructure, in particular for BvTv (correlation coefficient of 0.91 for UHR CT compared to 0.84 for NR CT) and TbSp (correlation of 0.74 for UHR CT and 0.047 for NR CT). The error obtained with UHR CT was generally smaller than that of NR CT. For TbSp, the mean deviation from μCT (averaged across all bone samples) was only ~0.07 for UHR CT, compared to 0.25 for NR CT. Analysis of reproducibility of texture features of trabecular bone between UHR CT and NR CT revealed fair correlations (>0.7) for the majority of GLCM features, but relatively poor CCC (e.g. 0.02 for Energy and 0.04 for Entropy). The magnitude of texture metrics is particularly affected by the enhanced spatial resolution of UHR CT.

CONCLUSION

The recently introduced UHR CT achieves improved correlation and reduced error in measurements of trabecular bone microstructure compared to conventional resolution CT. Future development of diagnostic strategies based on textural biomarkers derived from UHR CT will need to account for potential sensitivity of texture features to image resolution.

Identification and characterisation of a novel FT orthologous gene in London plane with a distinct expression response to environmental stimuli compared to PaFT

FLOWERING LOCUS T (FT) is a key integrator of environmental signals and internal cues, and codes for florigen-like activity which regulates the transition from vegetative to reproductive growth in flowering plants. Unlike annual plants, perennial tree species undergo several years of vegetative growth prior to the transition to the reproductive stage, as characterised by the ability to form flower buds. Thereafter, trees in temperate regions typically display an annual growth cycle involving distinct vegetative growth, flowering and dormancy stages. In London plane (Platanus acerifolia Willd.), a FT-like gene has previously been identified. Here, we report the isolation of a novel FT orthologous gene, PaFTL, and investigate the functions of PaFT and PaFTL through the analysis of expression profiles and transgenic phenotypes. PaFT displayed the highest levels of expression during tree dormancy, and similarly elevated expression levels were seen under conditions of low temperature and short days (LT/SD). In contrast, PaFTL transcripts were up-regulated during the floral transition phase, the early stages of inflorescence development and throughout the main flowering period, whereas expression levels were low and variable during dormancy and in response to LT/SD treatments. Ectopic expression of 35s::PaFTL in tobacco produced a phenotype similar to that with PaFT, namely, advanced floral initiation. Overall, the results suggest that PaFT and PaFTL have both conserved and diverse functions in floral initiation, floral development and dormancy regulation.

A Novel SCN9A Mutation (F826Y) in Primary Erythromelalgia Alters the Excitability of Nav1.7

BACKGROUND

Primary erythromelalgia (PE) is a dominant inherited disorder characterized by recurrent pain, redness, and warmth of the extremities that is caused by gain-of-function mutations in Nav1.7 encoding gene SCN9A. Most of the PE-causing mutations of Nav1.7 have been shown to be able to render Nav1.7-expressing cells hyperexcitable, however in most PE cases the symptoms are refractory to treatment with sodium channel blockers and the mechanism underlying the intractability has not been clearly clarified.

OBJECTIVE

To identify the mutation of SCN9A in a Chinese Han family with typical symptoms of PE and study the electrophysiological effect of the identified mutation.

METHODS

A Chinese Han family with typical symptoms of PE was collected and the proband's response to treatment was recorded. All the exons and flanking intronic sequences of SCN9A were amplified with PCR and sequenced. Several online programs were used to predict the damaging effect of variants. The functional effect of variants was studied by voltage-clamp analysis in CHO-K1 cells.

RESULTS

The PE symptoms of the proband are refractory to all kinds of reported medications. Sequence analysis of SCN9A showed that a novel c.2477T>A (p. F826Y) mutation co-segregated with the disease phenotype. Several online programs predicted that the F826Y mutation has a deleterious effect on the gene product. Voltage-clamp analysis showed that while compared with the wild-type channel, activation of the F826Y mutant channel was shifted by 7.7 mV in a hyperpolarizing direction, whereas steadystate inactivation was shifted by 4.3 mV in a depolarizing direction.

CONCLUSION

A novel disease-causing SCN9A Mutation (F826Y) was identified in a Chinese family with typical PE symptoms refractory to treatment. F826Y of Nav1.7 could render DRG neurons hyperexcitable, contributing to the pathogenesis of PE.

[Study on the negative regulation of TIPE2 from peripheral blood mononuclear cells on tissue factor in patients with bronchial asthma]

Objective: To investigate the expression of tumor necrosis factor alpha-inducible protein 8 like-2 (TIPE2) and tissue factor (TF) in patients with bronchial asthma. And to explore the regulation of TIPE2 on TF. Methods: Sixty-five asthmatic patients and 40 healthy controls were selected from the First Affiliated Hospital of Zhengzhou University from July to November, 2017. The expression of TIPE2 and TF in peripheral blood mononuclear cells of asthmatic patients and healthy controls were detected by Western blot.The level of TF protein in plasma was detected by enzyme-linked immunosorbent assay. The changes of TIPE2 and TF mRNA expression in THP-1 cells stimulated by house dust mite extract were detected by real-time fluorescence quantitative PCR (RT-PCR). The recombinant adenovirus Adv-TIPE2 was constructed and transfected into THP-1 cells and the effect of over-expression TIPE2 on TF expression in THP-1 cells was detected by RT-PCR. Results: The relative level of TIPE2 protein in asthmatic patients and healthy controls was 0.025±0.010 and 0.087±0.070, while that of TF was 0.40±0.27 and 0.15±0.10, respectively. Compared with healthy controls, the levels of TIPE2 protein decreased and TF protein increased in asthmatic patients, the differences were statistically significant (t=-5.06, 9.04, P<0.05) . TIPE2 protein level was negatively correlated with TF protein level (r=-0.460 3, P<0.05). The house dust mite extract reduced the expression level of TIPE2 mRNA in THP-1 cells, but increased the level of TF mRNA expression. When the concentration was 1 μg/ml, the change of TIPE2 mRNA was the most obvious at 4 h (P<0.05). The recombinant adenovirus Adv-TIPE2 was successfully constructed. The level of TF mRNA expression in THP-1 cells over-expressing TIPE2 gene was reduced (P<0.05). Conclusion: TIPE2, a negative regulator of inflammation, has a negative control effect on TF, and may be involved in the hyper-coagulable state of bronchial asthma by regulating TF expression.

Extensive tinea capitis and corporis in a child caused by Trichophyton verrucosum

A 3-year-old boy presented with multiple lesions of tinea corporis with dermatophytids, and subsequent inflammatory lesions with alopecia on the scalp. At the beginning, topical clobetasone butyrate was prescribed. The infection was diagnosed as dermatophytosis on the basis of positive direct microscopy and fungal culture. The etiological agent was isolated from all sampled sites and identified as Trichophyton verrucosum. Clonal nature of the infection was confirmed by random amplified polymorphic DNA (RAPD) analysis. The child lived in close vicinity of cattle. He was successfully treated with itraconazole.

Association of BNP with Frailty in Elderly Population: Rugao Longevity and Ageing Study

OBJECTIVES

To explore the associations of B-type natriuretic peptide (BNP) with physical frailty status as well as each domain of frailty in a general elderly population.

DESIGN

Cross-sectional analysis of prospective cohort study.

SETTING

All of 31 communities in Jiang'an township.

PARTICIPANTS

Overall 1338 participants (aged 70-89 years, mean 77.42±4.08 years) without a history of cardiovascular diseases in the third-wave of the aging arm of the Rugao Longevity and Aging Study (RuLAS).

MEASUREMENTS

Frailty was defined as the presence of ≥3 domains among five modified Fried's criteria (unintentional weight loss, low physical activity level, weakness (low grip strength), exhaustion, and slowness (slow gait speed)) and pre-frailty as the presence of 1-2 domains.

RESULTS

The prevalence of frailty and pre-frailty was 10.4% and 53.3%, respectively, in this elderly population. Elevated BNP (≥100 pg/mL) was significantly associated with pre-frailty (OR: 1.61, 95% CI: 1.13-2.29) and frailty (OR: 2.63, 95% CI: 1.61-4.32) after adjustment for covariates. In addition, elevated BNP was associated with low grip strength (OR: 2.00, 95% CI: 1.41-2.82) and low gait speed (OR: 1.62, 95% CI: 1.15-2.28) after adjustment for multiple covariates. Log BNP was inversely associated with grip strength (r= -0.265, p<0.001) and gait speed (r= -0.189, p<0.001).

CONCLUSION

Elevated plasma BNP was associated with increased risks of frailty, pre-frailty, and low levels of grip strength and gait speed in the elderly community people.

Pure red cell aplasia with t-cell large granular lymphocytic leukemia

Pure red cell aplasia (PRCA) develops as a result of erythroid precursors failing to reach maturity in the bone marrow, which eventually leads to anemia. Here we present a case of a 64-year-old Asian male with a medical history of colorectal adenocarcinoma who had been treated with 6 cycles of oxaliplatin and capecitabine four years ago. The patient was diagnosed with PRCA and T-cell large granular lymphocyte leukemia.

Interpretation of liver stiffness measurement-based approach for the monitoring of hepatitis B patients with antiviral therapy: A 2-year prospective study

Liver biopsy is not routinely performed in treated chronic hepatitis B. Liver stiffness measurement has been validated for noninvasive liver fibrosis assessment in pretreatment chronic hepatitis B but has not been assessed for fibrosis monitoring during antiviral therapy. Liver stiffness was systemically monitored by Fibroscan^® every 6 months in a cohort of patients with hepatitis B receiving antiviral therapy and compared with liver biopsies at baseline and week 104. A total of 534 hepatitis B e antigen-positive treatment-naive patients receiving telbivudine-based therapy with qualified liver stiffness measurement at baseline and week 104 were analyzed, 164 of which had adequate paired liver biopsies. Liver stiffness decreased rapidly (-2.2 kPa/24 weeks) in parallel with alanine aminotransferase (ALT) from 8.6 (2.6-49.5) kPa at baseline to 6.1 (2.2-37.4) kPa at week 24. Interestingly, liver stiffness decreased slowly (-0.3 kPa/24 weeks) but continually from week 24 to week 104 (6.1 vs 5.3 kPa, P < .001) while ALT levels remained stable within the normal range. More importantly, liver stiffness declined significantly irrespective of baseline ALT levels and liver necroinflammation grades. From baseline to week 104, the proportion of patients with no or mild fibrosis (Ishak, 0-2) increased from 74.4% (122/164) to 93.9% (154/164). Multivariate analysis revealed that percentage decline of 52-week liver stiffness from baseline was independently associated with 104-week liver fibrosis regression (odds ratio, 3.742; P = .016). Early decline of 52-week liver stiffness from baseline may reflect the remission of both liver inflammation and fibrosis and was predictive of 104-week fibrosis regression in treated patients with chronic hepatitis B.

Di-2-ethylhexyl phthalate (DEHP) exposure disturbs lipid metabolism in juvenile yellow catfish Tachysurus fulvidraco

This study was conducted to determine the mechanism by which di-2-ethylhexyl phthalate (DEHP) exposure influences lipid metabolism of juvenile yellow catfish Tachysurus fulvidraco. Fish were exposed to three DEHP concentrations (0, 0·1 and 0·5 mg l^-1 DEHP) for 8 weeks. Fatty acid synthase (FAS) activity significantly decreased with increasing DEHP concentrations, the highest value was in the Tween control group, whereas the lowest activities of carnitine palmitoyltransferase (CPT) and lipoprotein lipase (LPL) were in this group. The messenger (m)RNA levels of 6-phospho-gluconate dehydrogenase (6PGD), FAS and acetyl-CoA carboxylase a (ACCa) significantly increased with increasing DEHP concentration, the highest values were in the 0·5 mg l^-1 DEHP group. The mRNA level of peroxisome proliferator-activated receptor γ (PPARγ) was lower in Tween control than in fish exposed to 0·1 and 0·5 mg l^-1 DEHP. The highest mRNA level of ACCb was in the 0·1 mg l^-1 DEHP group. These results indicate that DEHP exposure can disturb lipid metabolism at the enzymatic and mRNA levels in Pelteobagrus fulvidraco.

Butylated caffeic acid: An efficient novel antioxidant

A novel antioxidant, butylated caffeic acid (BCA) was rationally designed by adding a tert-butyl group to caffeic acid, which was synthesized at a high yield (36.2%) from 2-methoxy-4-methylphenol by a four-step reaction including Friedel-Crafts alkylation, bromine oxidation, ether bond hydrolysis and Knoevenagel condensation. Its antioxidant capacity was much stronger than common commercial antioxidant tert-butyl hydroquinone (TBHQ) and its mother compound, caffeic acid, in both rancimat and deep frying tests. When investigated via the DPPH method, the antioxidant capacity of BCA was almost equal to TBHQ, but lower than caffeic acid. BCA could be a potentially strong antioxidant, especially for food processing at high temperatures such as deep frying and baking.

A systematic review on delayed absorption of subretinal fluid after scleral buckling for rhegmatogenous retinal detachment

Rhegmatogenous retinal detachment is a vision-threatening disease and is treated by either scleral buckling or pars planar vitrectomy. Rapid absorption of the subretinal fluid (SRF) helps in the early recovery of the vision. The absorption of SRF after the scleral buckling procedure is rapid, provided that the retinal break or breaks are closed at or after surgery. However, in some patients with rhegmatogenous retinal detachment, complete absorption of the SRF occur several weeks or months after the surgery. In this review, we discuss the factors influencing the rate of SRF absorption and the role of delayed absorption on visual recovery. We also discuss the therapeutic options for delayed SRF absorption and the available additional therapeutic options. Knowledge of the factors that influence the rate of SRF absorption, would enable the surgeon to predict the outcomes more accurately.

Abstract P6-07-31: Molecular mechanism of alcohol-associated breast cancer

Epidemiological studies have indicated that alcohol consumption is an established risk factor for breast cancer. The association of alcohol consumption and breast cancer is more pronounced in ER+ cases than in ER- cases. However, this molecular mechanism remains to be determined. Deregulation of RNA polymerase III (Pol III) transcription enhances cellular tRNAs and 5S rRNA production, increasing translational capacity to promote cell transformation and tumor formation. Our results reveal that alcohol increases Pol III gene transcription in both normal and cancer breast cell lines. The induction of Pol III genes by alcohol in ER+ breast cancer cells is significantly higher than in ER- normal breast cells and ER- breast cancer cells. E2 causes slight increase in Pol III gene transcription. The addition of ethanol to this system produces a marked increase. Alcohol increases ERa expression to enhance the cellular levels of Brf1 protein and mRNA. In addition, ethanol markedly stimulates phosphorylation of JNK1. Inhibition of JNK1 decreases ERE-Luc reporter activity and represses expression of ERa, Brf1 and Pol III genes. Reduction of ERa by its siRNA represses Brf1 and Pol III gene transcription. Ethanol with E2 produces larger and more numerous colonies. Repression of ERa or Brf1 inhibits alcohol-induced cell transformation. More interestingly, human biopsies studies show that Brf1 expression is significantly increased in nuclei of breast cancer cells, compared to tissue adjacent to the carcinoma. Together, these results support the idea that alcohol increases ERa expression through JNK1 pathway to elevate Brf1 expression and Pol III gene transcription, leading to greater phenotypic changes. ERa mediates Pol III gene transcription through Brf1, suggesting that ERa play a critical role in alcohol-induced deregulation of Pol III genes in ER+ breast cancer development.

*: The project is supported by NIAAA/NIH grants: AA017288, AA021114 and AA02324 to S Zhong.

Citation Format: Zhong S, Zhang Y, Lei J, Li W, Wu Z, Shi G. Molecular mechanism of alcohol-associated breast cancer [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P6-07-31.