Initial results from a prototype whole-body photon-counting computed tomography system

X-ray computed tomography (CT) with energy-discriminating capabilities presents exciting opportunities for increased dose efficiency and improved material decomposition analyses. However, due to constraints imposed by the inability of photon-counting detectors (PCD) to respond accurately at high photon flux, to date there has been no clinical application of PCD-CT. Recently, our lab installed a research prototype system consisting of two x-ray sources and two corresponding detectors, one using an energy-integrating detector (EID) and the other using a PCD. In this work, we report the first third-party evaluation of this prototype CT system using both phantoms and a cadaver head. The phantom studies demonstrated several promising characteristics of the PCD sub-system, including improved longitudinal spatial resolution and reduced beam hardening artifacts, relative to the EID sub-system. More importantly, we found that the PCD sub-system offers excellent pulse pileup control in cases of x-ray flux up to 550 mA at 140 kV, which corresponds to approximately 2.5×10¹¹ photons per cm² per second. In an anthropomorphic phantom and a cadaver head, the PCD sub-system provided image quality comparable to the EID sub-system for the same dose level. Our results demonstrate the potential of the prototype system to produce clinically-acceptable images in vivo.

A multi-centre randomised trial comparing ultrasound vs mammography for screening breast cancer in high-risk Chinese women

Background:

Chinese women tend to have small and dense breasts and ultrasound is a common method for breast cancer screening in China. However, its efficacy and cost comparing with mammography has not been evaluated in randomised trials.

Methods:

At 14 breast centres across China during 2008–2010, 13 339 high-risk women aged 30–65 years were randomised to be screened by mammography alone, ultrasound alone, or by both methods at enrolment and 1-year follow-up.

Results:

A total of 12 519 and 8692 women underwent the initial and second screenings, respectively. Among the 30 cancers (of which 15 were stage 0/I) detected, 5 (0.72/1000) were in the mammography group, 11 (1.51/1000) in the ultrasound group, and 14 (2.02/1000) in the combined group (P=0.12). In the combined group, ultrasound detected all the 14 cancers, whereas mammography detected 8, making ultrasound more sensitive (100 vs 57.1%, P=0.04) with a better diagnostic accuracy (0.999 vs 0.766, P=0.01). There was no difference between mammography and ultrasound in specificity (100 vs 99.9%, P=0.51) and positive predictive value (72.7 vs 70.0% P=0.87). To detect one cancer, the costs of ultrasound, mammography, and combined modality were $7876, $45 253, and $21 599, respectively.

Conclusions:

Ultrasound is superior to mammography for breast cancer screening in high-risk Chinese women.

Dental Abnormalities Caused by Novel Compound Heterozygous CTSK Mutations

Cathepsin K (CTSK) is an important protease responsible for degrading type I collagen, osteopontin, and other bone matrix proteins. The mutations in the CTSK gene can cause pycnodysostosis (OMIM 265800), a rare autosomal recessive bone dysplasia. Patients with pycnodysostosis have been reported to present specific dental abnormalities; however, whether these dental abnormalities are related to dysfunctional CTSK has never been reported. Here we investigated the histologic changes of cementum and alveolar bone in a pycnodysostosis patient, caused by novel compound heterozygous mutations in the CTSK gene (c.87 G>A p.W29X and c.848 A>G p.Y283C). The most impressive manifestations in tooth were extensive periradicular high-density clumps with unclear periodontal space by orthopantomography examination and micro-computed tomography scanning analysis. Hematoxylin/eosin and toluidine blue staining and atomic force microscopy analysis showed that the cementum became significantly thickened, softened, and full of cementocytes. The disorganized bone structure was the main character of alveolar bone. The p.W29X mutation may represent the loss-of-function allele with an earlier termination codon in the precursor CTSK polypeptide. Residue Y283 is highly conserved among papain-like cysteine proteases. Three-dimensional structure modeling analysis found that the loss of the hydroxybenzene residue in the Y283C mutation would interrupt the hydrogen network and possibly affect the self-cleavage of the CTSK enzyme. Furthermore, p.Y283C mutation did not affect the mRNA and protein levels of overexpressed CTSK in COS-7 system but did reduce CTSK enzyme activity. In conclusion, the histologic and ultrastructural changes of cementum and alveolar bone might be affected by CTSK mutation via reduction of its enzyme activity (clinical trial registration: ChiCTR-TNC-10000876).

The distribution of kisspeptin (Kiss)1- and Kiss2-positive neurones and their connections with gonadotrophin-releasing hormone-3 neurones in the zebrafish brain

Kisspeptin is a neuroendocrine hormone with a critical role in the activation of gonadotrophin-releasing hormone (GnRH) neurones, which is vital for the onset of puberty in mammals. However, the functions of kisspeptin neurones in non-mammalian vertebrates are not well understood. We have used transgenics to labell kisspeptin neurones (Kiss1 and Kiss2) with mCherry in zebrafish (Danio rerio). In kiss1:mCherry transgenic zebrafish, Kiss1 cells were located in the dorsomedial and ventromedial habenula, with their nerve fibres contributing to the fasciculus retroflexus and projecting to the ventral parts of the interpeduncular and raphe nuclei. In kiss2:mCherry zebrafish, Kiss2 cells were primarily located in the dorsal zone of the periventricular hypothalamus and, to a lesser extent, in the periventricular nucleus of the posterior tuberculum and the preoptic area. Kiss2 fibres formed a wide network projecting into the telencephalon, the mesencephalon, the hypothalamus and the pituitary. To study the relationship of kisspeptin neurones and GnRH3 neurones, these fish were crossed with gnrh3:EGFP zebrafish to obtain kiss1:mCherry/gnrh3:EGFP and kiss2:mCherry/gnrh3:EGFP double transgenic zebrafish. The GnRH3 fibres ascending to the habenula were closely associated with Kiss1 fibres projecting from the ventral habenula. On the other hand, GnRH3 fibres and Kiss2 fibres were adjacent but scarcely in contact with each other in the telencephalon and the hypothalamus. The Kiss2 and GnRH3 fibres in the ventral hypothalamus projected into the pituitary via the pituitary stalk. In the pituitary, Kiss2 fibres were directly in contact with GnRH3 fibres in the pars distalis. These results reveal the pattern of kisspeptin neurones and their connections with GnRH3 neurones in the brain, suggesting distinct mechanisms for Kiss1 and Kiss2 in regulating reproductive events in zebrafish.

Robust and tunable 16.375Gb/s dual-band optical OFDM transmissions over directly modulated VCSEL-based 200m OM2 MMFs

Utilizing low-cost, 2.2GHz modulation bandwidth, uncooled and standalone directly modulated VCSEL (DM-VCSEL)-based real-time dual-band optical OFDM (OOFDM) transmitters, aggregated 16.375Gb/s transmissions of OOFDM signals having bandwidths approximately 3.8 times higher than the VCSEL manufacturer-specified modulation bandwidths, are experimentally demonstrated, for the first time, over 200m OM2 MMF links based on intensity modulation and direct detection. The aggregated signal transmission capacities of the aforementioned links vary by just 8% for various OM2 MMFs ranging from 100m to 500m, and by just 10% over a 1GHz passband carrier frequency detuning range. Such dual-band OOFDM adaptability-induced excellent performance robustness and large passband frequency tunability can significantly relax the requirements on VCSEL modulation bandwidth for achieving specific transmission performances for cost-sensitive application scenarios such as data centers.

Development and in vitro/in vivo evaluation of a silastic intravaginal ring for mifepristone delivery

Preparation and in vitro/in vivo evaluation of mifepristone intravaginal ring formulations were investigated. In the present study, it is reported that a mifepristone intravaginal ring of reservoir design comprising of a mifepristone silicone elastomer core enclosed in a silicone layer. During the preparation of intravaginal ring solid dispersion method was employed which improved the release rate of drug from the intravaginal ring. In vitro release studies performed under sink conditions and the released drug amounts were estimated using UV spectrometry at 310 nm. In addition, the in vivo release profile of in-house devices was evaluated in female New Zealand white rabbits. The rabbit plasma samples were processed and analyzed using a validated HPLC-MS method. Norgestrel was used as internal standard, and plasma samples contained mifepristone and internal standard were deproteinized, and then subjected to HPLC-MS analysis under condition of electrospray ionization in the selected ion monitoring mode. The drug release from intravaginal ring made in house was constant for 21 days in rabbits, which suggested the mifepristone intravaginal ring release system would be useful in clinical practice in the future. The result indicated the in vitro/in vivo correlation is perfect, which explained in vitro release analysis method developed was feasible.

The accuracy of ultrasonography and magnetic resonance imaging for the diagnosis of Morton's neuroma: a systematic review

AIM

To determine the accuracy of MRI versus ultrasound for Morton's neuroma.

MATERIALS AND METHODS

A search was undertaken for clinical studies published in any language in PubMed up to the date of December 2013. Studies assessing the accuracy of the ultrasound or MRI for the diagnosis of Morton's neuroma were included. Data were pooled for meta-analysis. Study selection, data collection, and extraction were performed independently by two authors. Meta-disc 1.4 and Revman 5.2 software were applied for statistical analysis.

RESULTS

The study included 12 studies; 217 patients underwent MRI and 241 underwent ultrasound examinations. There appeared greater diagnostic accuracy for ultrasound than MRI for the diagnosis of Morton's neuroma (ultrasound sensitivity 90%, specificity 88%, positive likelihood ratio 2.77, negative likelihood ratio 0.16 versus MRI sensitivity 93%, specificity 68%, positive likelihood ratio 1.89, negative likelihood ratio 0.19).

CONCLUSIONS

The available evidence suggests that ultrasound can provide better accuracy for the diagnosis of Morton's neuroma than MRI.

Personal inhalation exposure to polycyclic aromatic hydrocarbons in urban and rural residents in a typical northern city in China

Personal inhalation exposure samples were collected and analyzed for polycyclic aromatic hydrocarbons (PAHs) for 126 selected volunteers during heating and non-heating seasons in a typical northern Chinese city, Taiyuan. Measured personal PAH exposure levels for the urban residents in the heating and non-heating seasons were 690 (540-1051) and 404 (266-544) ng/m(3) , respectively, while, for the rural residents, they were 770 (504-1071) and 312 (201-412) ng/m(3) , respectively. Thus, rural residents are exposed to lower PAH contamination in comparison with the urban residents in the non-heating seasons. In the heating season, personal PAH inhalation exposure levels were comparable between the urban and rural residents, in part owing to the large rate of residential solid fuel consumption in the rural area for household cooking and heating. The estimated incremental lifetime cancer risks (ILCR) due to PAH exposure in Taiyuan were 3.36 × 10(-5) and 2.39 × 10(-5) for the rural and urban residents, respectively, significantly higher than the literature-reported national average level, suggesting an urgent need of PAH pollution control to protect human health.

Real-time experimental demonstrations of software reconfigurable optical OFDM transceivers utilizing DSP-based digital orthogonal filters for SDN PONs

Real-time optical OFDM (OOFDM) transceivers with on-line software-controllable channel reconfigurability and transmission performance adaptability are experimentally demonstrated, for the first time, utilizing Hilbert-pair-based 32-tap digital orthogonal filters implemented in FPGAs. By making use of an 8-bit DAC/ADC operating at 2GS/s, an oversampling factor of 2 and an EML intensity modulator, the demonstrated RF conversion-free transceiver supports end-to-end real-time simultaneous adaptive transmissions, within a 1GHz signal spectrum region, of a 2.03Gb/s in-phase OOFDM channel and a 1.41Gb/s quadrature-phase OOFDM channel over a 25km SSMF IMDD system. In addition, detailed experimental explorations are also undertaken of key physical mechanisms limiting the maximum achievable transmission performance, impacts of transceiver's channel multiplexing/demultiplexing operations on the system BER performance, and the feasibility of utilizing adaptive modulation to combat impairments associated with low-complexity digital filter designs. Furthermore, experimental results indicate that the transceiver incorporating a fixed digital orthogonal filter DSP architecture can be made transparent to various signal modulation formats up to 64-QAM.

MicroRNA-130a inhibits HCV replication by restoring the innate immune response

Hepatitis C virus (HCV) infection is a major cause of chronic hepatitis and hepatocellular carcinoma. Currently pegylated interferon (IFN) combined with ribavirin remains the best therapeutic approach, although patients infected with HCV genotype I may benefit from adding protease inhibitors as 'triple therapy'. MicroRNAs (miRNAs) are endogenous small noncoding RNAs that regulate gene expression and have recently been shown to play an important role in human innate immune response and as an antiviral in chimpanzees. We studied the effect of miR-130a on the HCV replication. We found that miR-130a significantly inhibits HCV replication in both HCV replicon and J6-/JFH1-infected cells. Over expression of miR-130a upregulated the expression of type I IFN (IFN-α/IFN -β), ISG15, USP18 and MxA, which are involved in innate immune response and decreased expression of miR-122, a well-defined miRNA promoting HCV production. In conclusion, miR-130a inhibits HCV replication/production by restoring host innate immune responses and/or downregulating pro-HCV miR-122. miR-130a might be a potential drug target by modulating host innate immune responses to combat HCV infection.

A comparison of serum and sputum inflammatory mediator profiles in patients with asthma and COPD

OBJECTIVE

To investigate serum and sputum cytokine profiles in asthma and chronic obstructive pulmonary disorder (COPD).

METHODS

Clinical characteristics, blood and sputum samples were collected from asthma (n = 37) and COPD (n = 36) patients, and healthy subjects (n = 39). Cytokines were measured by enzyme-linked immunosorbent assay (ELISA) and inflammation antibody array; levels were analysed according to smoking status and presence of eosinophilia in the airways of COPD/asthma patients, and compared with those in healthy subjects.

RESULTS

ELISA revealed a significant difference in the expression of only a few cytokines in the COPD versus asthma groups, and in both patient groups compared with healthy subjects. The antibody array showed greater differentiation in inflammatory mediators. In the subphenotype analysis, the differential expression of cytokines was more significant between eosinophilic and noneosinophilic airway inflammation than between asthma and COPD, according to both the ELISA and antibody array. There was little difference in cytokine expression between smoking and nonsmoking subgroups.

CONCLUSIONS

Differential expression of inflammatory mediators is present between patients with COPD or asthma, and eosinophilic or noneosinophilic airway inflammation, and contributes to understanding the cytokine network of airway inflammation.

Ion channels, channelopathies, and tooth formation

The biological functions of ion channels in tooth development vary according to the nature of their gating, the species of ions passing through those gates, the number of gates, localization of channels, tissue expressing the channel, and interactions between cells and microenvironment. Ion channels feature unique and specific ion flux in ameloblasts, odontoblasts, and other tooth-specific cell lineages. Both enamel and dentin have active chemical systems orchestrating a variety of ion exchanges and demineralization and remineralization processes in a stage-dependent manner. An important role for ion channels is to regulate and maintain the calcium and pH homeostasis that are critical for proper enamel and dentin biomineralization. Specific functions of chloride channels, TRPVs, calcium channels, potassium channels, and solute carrier superfamily members in tooth formation have been gradually clarified in recent years. Mutations in these ion channels or transporters often result in disastrous changes in tooth development. The channelopathies of tooth include altered eruption (CLCN7, KCNJ2, TRPV3), root dysplasia (CLCN7, KCNJ2), amelogenesis imperfecta (KCNJ1, CFTR, AE2, CACNA1C, GJA1), dentin dysplasia (CLCN5), small teeth (CACNA1C, GJA1), tooth agenesis (CLCN7), and other impairments. The mechanisms leading to tooth channelopathies are primarily related to pH regulation, calcium homeostasis, or other alterations of the niche for tooth eruption and development.

Nicotine induces alteration of H3K27 demethylase UTX in kidney cancer cell

Cigarette smoking is one of the most important risk factors for kidney cancer, but the molecular mechanism is poorly understood. To examine the expression change of histone H3 on lysine 27 trimethylase (H3K27me3) demethylases ubiquitously transcribed TPR gene on the X chromosome (UTX) in kidney cancer cell line 786-O after nicotine treatment, quantitative real-time-polymerase chain reaction and western blotting analysis were carried out. These results showed that nicotine can increase UTX messenger RNA and protein levels and also decrease the content of H3K27me3. The decreased content of H3K27me3 may activate specific gene expression and lead to kidney cancer. Future investigation on nicotine induced UTX expression and its epigenetic effect would deepen our understanding on nicotine toxicity and carcinogenicity.

Downregulation of endogenous intermedin augmented myocardial injury in rats with ischemia/reperfusion

Intermedin (IMD) plays an important regulatory role in cardiovascular function. We aimed to explore the protein expression of IMD and its receptors, calcitonin receptor-like receptor (CRLR) and receptor activity-modifying proteins (RAMPs), and the role of endogenous IMD in myocardial ischemia/reperfusion (I/R) injury in rats. The rat model of I/R was created by ligating cardiac left anterior descending artery. Western blot was used to determine protein expression of CRLR and RAMPs, and radioimmunoassay was used to detect IMD content. Compared with control, protein levels of CRLR and RAMPs in both ischemic and nonischemic region were upregulated at different stages of reperfusion. IMD protein content in nonischemic area myocardium also increased. However, IMD protein content in ischemic area downregulated at 3-, 6-, and 12-h reperfusion. In hypoxia/reoxygenation model of neonatal cardiomyocytes, IMD attenuated myocyte injury, and IMD receptor antagonist IMD17-47 aggravated myocyte impairment by blocking endogenous IMD. In conclusion, the downregulation of IMD at early stage of reperfusion might augment myocardium injury.

Abstract PD10-02: Metabolic syndrome and recurrence within the 21-gene recurrence score assay risk categories in lymph node negative breast cancer

Background: The incidence of the metabolic syndrome (MS) has been increasing in the United States and elsewhere. The interaction of MS with breast cancer (BC) incidence, tumor biology and outcomes are under study. We hypothesized that the presence of MS would predict BC recurrence to a variable degree across the diverse BC biology as defined by the risk categories of the 21-gene recurrence score (RS) assay.

Patients and Methods: We studied consecutive patients (pts) with newly diagnosed, estrogen receptor (ER) positive, lymph node (LN) negative BC treated in our institution between 2006–2011 who had a 21-gene RS assay done on their tumors. All pts were treated with standard systemic and local therapy. The electronic medical record was queried for key diagnoses including MS and its constituent parts. The WHO definition was used to categorize pts as having MS defined as diabetes mellitus (DM) or glucose intolerance, plus at least 2 of the following: hypertension (HTN), dyslipidemia (HL), central obesity and microalbuminemia. Tumor characteristics including Ki67 index, grade, tumor size, HER2/neu status; and pt characteristics including age, race, menopausal status, body mass index were recorded. The association of MS and the tumor and patient characteristics with the RS tertiles of low, intermediate and high risk was analyzed.

Results: We identified 332 pts, median age 62 years, of whom 88 (27%) had MS. There was no significant association between the MS and any of the patient or tumor variables including the 21-gene RS assay, except for race (p = 0.004). Eleven of 21 (52%) African-American women had MS, 68 of 284 (24%) Caucasian women had MS, and 9 of 21 (43%) others including Hispanic and Asian women had MS. However, there was a significant association between recurrence and MS (p = 0.0002) independent of other factors. Of the 21 pts who recurred, 13 (61.9%) had MS. There was an association of recurrence and MS within RS tertiles. For pts with low risk scores, 7/44 (15.9%) with MS vs. 1/126 (0.79%) without MS had recurrence (p = 0.0003). For pts with intermediate risk scores, 5/30 (16.67%) with MS vs. 4/83 (4.82%) without MS had recurrence (p = 0.05). For patients with high risk scores, 1/9 (11.11%) with MS vs. 2/15 (13.33%) without MS had recurrence (p = 1).

Conclusion: MS is an independent risk factor for BC recurrence among women with LN negative, ER positive BC treated with standard adjuvant therapy. There is a striking impact of MS on recurrence in pts with tumor biologies defined by low (and to a lesser degree) intermediate risk 21-gene RS assay scores. However, there is no difference in recurrence risk by MS among those pts with high RS. This implies that interventions directed at modifying MS in newly diagnosed pts with early BC may potentially favorably impact survival in those with specific tumor biologies as defined by multigene assays. Thus, long-term prospective studies should be conducted to further evaluate both the short and long term effects of MS on BC outcomes.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr PD10-02.

Expression of microRNAs during chondrogenesis of human adipose-derived stem cells

OBJECTIVES

MicroRNAs (miRNAs) play an important role in the regulation of chondrogenesis of mesenchymal stem cells, but their expression still remains unknown in human adipose-derived stem cells (hADSCs). In this study the miRNA expression profile during chondrogenic differentiation of hADSC and the potential mechanism whereby miRNAs may affect the process of chondrogenesis are considered.

METHODS

hADSCs were isolated and cultured. The expression of chondrogenic proteins was detected using enzyme-linked immunosorbent assay (ELISA). miRNA expression profiles before and after chondrogenic induction were obtained using miRNA microarray essay and differently expressed miRNAs were primarily verified using quantitative real-time polymerase chain reaction (qRT-PCR). Putative targets of the miRNAs were predicted using online software programs MiRanda, TargetScan and miRBase.

RESULTS

Twelve miRNAs were found to be differentially expressed pre- and post-chondrogenic induction by over a two-fold change, including eight up-regulated miRNAs (miR-193b, miR-199a-3p/hsa-miR-199b-3p, miR-455-3p, miR-210, miR-381, miR-92a, miR-320c, and miR-136), and four down-regulated miRNAs (miR-490-5p, miR-4287, miR-BART8*, and miR-US25-1*). qRT-PCR analysis further confirmed these results. Predicted target genes of the differentially expressed miRNAs were based on the overlap of at least two online prediction algorithms, with the known functions of regulating chondrogenic differentiation, self-renewal, signal transduction and cell cycle control.

CONCLUSIONS

In this study we have identified a group of miRNAs and their target genes, which may play important roles in regulating chondrogenic differentiation of hADSCs. Our results provide the basis for further investigation into the molecular mechanism of chondrogenesis in hADSCs and their differentiation for cartilage engineering.

Incorporation of cell-adhesion peptides into collagen scaffolds promotes corneal epithelial stratification

The objective of this study was to examine the effects of cell-adhesion peptides incorporated into collagen scaffolds on corneal epithelial cell stratification. Peptides (YIGSR, YIGSRIKVAV, IKVAVYIGSR and negative control YISGR) were first chemically attached to dendrimers. The peptide-modified dendrimers were then used as collagen cross-linkers. This permitted the incorporation of the peptides into the bulk structure of the collagen gels. The amount of peptide incorporated into the collagen gels was determined by 125I radiolabelling to be between 0.064 and 6.4 microg/mg collagen for YIGSR, and between 0.1187 to 11.87 microg/mg collagen for YIGSRIKVAV and IKVAVYIGSR. Corneal epithelial cell monolayers were grown on the surface of the collagen scaffolds and then exposed to conditions that promoted stratification as a stratified epithelial layer is desired in a tissue-engineered cornea. It was found that all of the incorporated peptides promoted stratification of the cells with the exception of the negative control YISGR. A synergistic effect of the combined sequences from laminin was observed, with the orientation of the peptide sequences having a great impact on the ability of the materials to promote cell stratification.

The expression of histone demethylase JMJD1A in renal cell carcinoma

BACKGROUND

Hypoxia-inducible factor 1α has been shown to play a central role in RCC tumorigenesis by acting as a transcription factor. Histone demethylase JMJD1A is an iron- and 2-oxoglutarate-dependent dioxygenase which catalyze the demethylation of mono- and dimethylated H3K9. JMJD1A can be upregulated by hypoxia via HIF-1 and associated with cancer. The expression of JMJD1A was determined in 10 kidney cancer tissue and adjacent tissue by quantitative polymerase chain reaction, western blotting and immunohistochemistry. Furthermore, the expression of JMJD1A was investigated in cell line 786-0 through adding nickle or cobalt ion to mimic hypoxic environment. The expression of JMJD1A was higher in cancer tissue than adjacent tissue, and in hypoxic environment than normal environment. In cancer tissue, the JMJD1A mainly located around blood vessels which indicated that JMJD1A is involved tumor angiogenesis.

CONCLUSION

the increased expression of JMJD1A might be associated with the progression of kidney cancer.

KEYWORDS

renal cell carcinoma, histone demethylase, JMJD1A, hypoxia-inducible factor, iron.