CT Method Research Articles

Anthropomorphic phantom for deformable lung and liver CT and MR imaging for radiotherapy

In this study, a functioning and ventilated anthropomorphic phantom was further enhanced for the purpose of CT and MR imaging of the lung and liver. A deformable lung, including respiratory tract was 3D printed. Within the lung’s inner structures is a solid region shaped from a patient’s lung tumour and six nitro-glycerine capsules as reference landmarks. The full internal mesh was coated, and the tumour filled, with polyorganosiloxane based gel. A moulded liver was created with an external casing of silicon filled with polyorganosiloxane gel and flexible plastic internal structures. The liver, fitted to the inferior portion of the right lung, moves along with the lung’s ventilation. In the contralateral side, a cavity is designed to host a dosimeter, whose motion is correlated to the lung pressure. A 4DCT of the phantom was performed along with static and 4D T1 weighted MR images. The CT Hounsfield units (HU) for the flexible 3D printed material were −600–100 HU (lung and liver structures), for the polyorganosiloxane gel 30–120 HU (lung coating and liver filling) and for the silicon 650–800 HU (liver casing). The MR image intensity units were 0–40, 210–280 and 80–130, respectively. The maximum range of motion in the 4D imaging for the superior lung was 1–3.5 mm and 3.5–8 mm in the inferior portion. The liver motion was 5.5–8.0 mm at the tip and 5.7–10.0 mm at the dome. No measurable drift in motion was observed over a 2 h session and motion was reproducible over three different sessions for sin2(t), sin4(t) and a patient-like breathing curve with the interquartile range of amplitudes for all breathing cycles within 0.5 mm. The addition of features within the lung and of a deformable liver will allow the phantom to be used for imaging studies such as validation of 4DMRI and pseudo CT methods.

MP36-19 INVESTIGATING RISK FACTORS OF NEPHROLITHIASIS FROM THE CLINICAL IMAGES TO THE GENETIC BIOINFORMATICS

You have accessJournal of UrologyImaging/Radiology: Uroradiology I (MP36)1 Apr 2020MP36-19 INVESTIGATING RISK FACTORS OF NEPHROLITHIASIS FROM THE CLINICAL IMAGES TO THE GENETIC BIOINFORMATICS Zhu Yunpeng* and Zeng Xiaoyong Zhu Yunpeng*Zhu Yunpeng* More articles by this author and Zeng XiaoyongZeng Xiaoyong More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000000880.019AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: To investigate the correlation among abdominal aortic calcification, the calcification of renal papillary tips and nephrolithiasis though imaging in CT and bioinformatics methods. METHODS: This retrospective study included 163 kidney stone-formers and 168 age- and sex-matched control participants without urolithiasis and histories of urolithiasis. The clinical data including age, gender and comorbidities were collected. Aortic calcification index (ACI) of aorta abdominalis, bone mineral density (BMD) of the first lumbar vertebra and the attenuation of renal papillary tips were measured in CT. Multivariate logistic regression analysis was performed to the correlation among ACI, the attenuation of renal papillary tips and nephrolithiasis. Additionally, through the GEO database, the gene expression analyses of aortic calcification (GSE100927) and nephrolithiasis (GSE100927) were performed to evaluate the inner connection in the level of genetic expression. RESULTS: These data showed that the stone-formers had the higher attenuation of renal papillary tips. There was no significant difference in the prevalence of abdominal aortic calcification, however, ACI of participants with abdominal aortic calcification was significantly higher in the stone group. Multivariate logistic regression analysis showed that ACI and the attenuation of renal papillary tips were significantly correlated with nephrolithiasis. Through bioinformatics methods, the same Differentially Expressed Genes of 8 upregulated genes and 17 downregulated genes were screened out and we found that some important signaling pathways were activated in both nephrolithiasis and arterial calcificatio. CONCLUSIONS: This study demonstrates that the stone-formers have the higher attenuation of renal papillary tips, which gives us a hint that the higher attenuation of renal papillary tips may predict the occurrence nephrolithiasis and is supposed to be a junction between nephrolithiasis and arterial calcification. A significant correlation between aortic calcification and nephrolithiasis was proved again and some important genes and signaling pathways were considered to be the inner connection between nephrolithiasis and arterial calcification. Source of Funding: National Natural Science Foundation of China, Project (No.81570631 and No.81600544) © 2020 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 203Issue Supplement 4April 2020Page: e530-e530 Advertisement Copyright & Permissions© 2020 by American Urological Association Education and Research, Inc.MetricsAuthor Information Zhu Yunpeng* More articles by this author Zeng Xiaoyong More articles by this author Expand All Advertisement PDF downloadLoading ...

Modulation of Cannabinoid System and Proinflammatory Cytokine mRNAs in Central and Peripheral Tissue in a Rodent E. coli Sepsis Model

Cytokine production is regulated by the endogenous cannabinoid system (ECS) in many pro‐inflammatory conditions. Sepsis is a highly morbid condition that results from a dysregulated host response to infection. Our previous work showed that ventilatory pattern variability (VPV) decreased concomitantly with increased pro‐inflammatory cytokine production. However, the ECS has not been integrated with transcriptional regulation of pro‐inflammatory cytokines nor with VPV during the progression to sepsis. We hypothesized that decreases in VPV correlate with increased cannabinoid receptor (Cnr) 1 & 2 and pro‐inflammatory cytokine mRNAs. We implanted a fibrin clot that contained either 0 or 25×106E. coli in the peritoneal cavity of adult, male rats (n=24). Respiratory measures were obtained prior to clot implantation and again 1 hour (h) prior to euthanasia. At 3, 6, or 12 h following the clot implantation the rostral and caudal medulla, lung, heart and liver were harvested. VPV was computed with a group of linear and nonlinear dynamic measurements. Total RNA was extracted using Trizol reagent, and cDNA was synthesized using reverse transcription PCR. Quantitative real‐time PCR was performed in duplicate for each sample using TaqMan Gene® Expression Assays specific for 18S ribosomal RNA (18S), Glyceraldehyde 3‐phosphate dehydrogenase (Gapdh), beta actin (Actb), Cnr1 & 2, interleukin (IL) 1‐beta (Il1b) & Il6 and tumor necrosis factor‐alpha (Tnfa). The most stable reference gene combination was determined using NormFinder software and each target gene was normalized to the geometric mean of these reference genes. Relative quantitation of gene expression was performed using the comparative CT method (2−ΔΔCT method) with the 0 E. coli fibrin clot groups (n=4/group) at each time point as the comparative control. At 12 h after inoculation, expiratory duration decreased [F(2,18) = 4.01, p = 0.036] and the ventilatory waveform became more predictable (increased mutual information [F(2,18) = 5.56, p = 0.013] and decreased sample entropy [F(2,18) = 4.25, p = 0.031]). The fold change in cytokine and ECS gene expression varied with tissue. At 12 h after inoculation gene expression increased in heart and rostral medulla, while gene expression decreased in lung, caudal medulla and liver. These preliminary data and analyses support our hypothesis that decreased VPV observed at 12 h is associated with increased expression of ECS and pro‐inflammatory cytokines in heart and rostral medulla. In lung and caudal medulla, however, expression of pro‐inflammatory cytokines decreased, while Cnr1 increased in caudal medulla and Cnr2 increased in lung tissue. Further research is needed to determine how modulation of the ECS can effectively regulate proinflammatory cytokine production and changes in VPV.Support or Funding InformationNIH 5T32HL007913‐18, NIH U01 EB021960, VA Research Service I01BX004197

Assessing the fit of 3D printed bolus from CT, optical scanner and photogrammetry methods.

Bolus plays an important role in the radiation therapy of superficial lesions and the application of 3D printing to its design can improve fit and dosimetry. This study quantitatively compares the fits of boluses designed from different imaging modalities. A head phantom was imaged using three systems: a CT simulator, a 3D optical scanner, and an interchangeable lens camera. Nose boluses were designed and 3D printed from each modality. A 3D printed phantom with air gaps of known thicknesses was used to calibrate mean HU to measure air gaps of unknown thickness and assess the fit of each bolus on the head phantom. The bolus created from the optical scanner data resulted in the best fit, with a mean air gap of 0.16mm. Smoothing of the CT bolus resulted in a more clinically suitable model, comparable to that from the optical scanner method. The bolus produced from the photogrammetry method resulted in air gaps larger than 1mm in thickness. The use of optical scanner and photogrammetry models have many advantages over the conventional bolus-from-CT method, however workflow should be refined to ensure accuracy if implemented clinically.

Reference gene selection and validation for mRNA expression analysis by RT-qPCR in murine M1- and M2-polarized macrophage.

Murine bone marrow-derived macrophages (M0) and M1- and M2-polarized macrophages are being widely used as a laboratory model for polarized macrophages related molecular mechanism analysis. Gene expression analysis based on reference gene normalization using RT-qPCR was a powerful way to explore the molecular mechanism. But little is known about reference genes in these cell models. So, the goal of this study was to identify reference genes in these types of macrophages. Candidate reference genes in murine bone marrow-derived and polarized macrophages were selected from microarray data using Limma linear model method and evaluated by determining the stability value using five algorithms: BestKeeper, NormFinder, GeNorm, Delta CT method, and RefFinder. Finally, the selected stable reference genes were validated by testing three important immune and inflammatory genes (NLRP1, IL-1β, and TNF-α) in the cell lines. Our study has clearly shown that Ubc followed by Eef1a1 and B2m respectively were recognized as the three ideal reference genes for gene expression analysis in murine bone marrow-derived and polarized macrophages. When three reference genes with strong different stability were used for validation, a large variation of a gene expression level of IL-1β, TNF-α and NLRP1 were obtained which provides clear evidence of the need for careful selection of reference genes for RT-qPCR analysis. Normalization of mRNA expression level with Ubc rather than Actb or Gusb by qPCR in macrophages and polarized macrophages is required to ensure the accuracy of the qPCR analysis.

Toxin A and B genes expression of Clostridium difficile in the sub-minimum inhibitory concentration of clindamycin, vancomycin and in combination with ceftazidime

Antibiotics prescribed for infections have diverse effects on microbiota and the pathogen Clostridium difficile (C. difficile) as the most important antibiotic-associated diarrhea. This study aims to determine the gene expression of toxins A and B at the transcription level in the sub-MIC of vancomycin (VAN), clindamycin (CLI), and ceftazidime (CAZ) alone and in combination. The MIC and fractional inhibitory concentration (FIC) of two C. difficile samples (a clinical isolate and ATCC 9689) were determined by microdilution and checkerboard microdilution methods, respectively. The total RNA was extracted from the medium inoculated with ∼106 CFU/mL of fresh bacteria in the pre-reduced medium containing ½ MIC of antibiotics alone and ½ FIC of antibiotics in combination. Real-time PCR was performed by sybrGreen methods in triplicate, and the data were analyzed by the comparative ΔΔCT method. All antibiotics except CAZ (alone and in combination) decreased the gene expression of toxins A and B within 24 hours. VAN and CLI reduced toxin gene expression within 24 and 48 hours. However, CAZ alone and in combination with VAN as well as CLI increased the gene expression of toxins A and B. The results confirmed toxin gene transcription and toxin production are associated with the type of isolates and antibiotics, as well as the combined form of antibiotics. This could be the reason which can explain the occurrence of C. difficile infection among patients who were treated with the third generation of cephalosporins alone and in combination with another antibiotic in the form of combinational therapy.

Differential exosome miRNA expression in oral cancer stem cells

BackgroundOral squamous cell carcinomas (OSCC) secrete exosomes into the surrounding extracellular environment to promote the horizontal transfer of bioactive molecules including microRNA (miRNA). The primary objective of this study was to explore potential differences in miRNA content between OSCC and OSCC stem cells.MethodsThe OSCC cell lines SCC4, SCC15, SCC25 and CAL27 were used in these studies. The corresponding OSCC stem cells that demonstrated phenotypic adhesion independent tumor spheres (AiTS) were manually isolated. All cells were cultured in DMEM containing 10% exosome-free fetal bovine serum. Exosomes were isolated using Total Exosome Isolation reagent (Invitrogen) and RNA was purified using Total Exosome RNA isolation kit (Invitrogen). Exosome miRNA content was evaluated using miRNA Advanced Taqman Assays for miR-21, − 155, − 133, − 34, − 31, − 32, and − 365. The fold change of miRNA content was calculated using the comparative CT (ΔΔCT) method using miR-16 as an endogenous control.ResultsAfter successful cell cultures were established, AiTS (cancer stem cells) were manually separated and confirmed using CD133 and Sox-2 biomarkers. Exosomes and extracellular vesicles were successfully isolated from all cell lines and AiTS isolates for miRNA screening. All isolates exhibited miR-16 expression (positive control), but none contained mir-31, − 32, or 133a. Differential expression of miR-21, miR-34 and miR-155 were observed with patterns observed among the cancer cell lines which were distinct from the corresponding AiTS isolates.ConclusionsExosomes isolated from these different OSCC stem cell populations displayed nearly consistent downregulation/loss of miR-21 and miR-34 suggesting the possibility of a unique miRNA profile characteristic of oral cancer stem cells. These findings highlight the need to investigate the comprehensive functions of miR-21 and miR-34 in tumor progression and continued research to refine a miRNA profile that could aid in distinguishing tumors with poor prognosis.

Developing computational thinking with a module of solved problems

AbstractComputational thinking (CT) has been recognized as a collection of understandings and skills required for new generations of students not only proficient at using tools, but also at creating them and understanding the implication of their capabilities and limitations.The objective of this research was to develop a module of solved problems for the development of CT in first‐year computer engineering students at the University of Cienfuegos, Cuba. Students depend on current research to understand the definition, function, and culture of CT and to consider how it can improve their analytical and critical skills. A contextualized definition of the CT method is proposed as a cognitive process executed by humans to solve problems using computational concepts. This method improves CT in terms of decomposition, pattern recognition, algorithm design, abstraction, data representation, problem decomposition, algorithmic thinking, and generalization of patterns, simulation and evaluation. The research carried out is an experimental design with a pretest and a posttest, with a control group and an experimental group to which the intervention was applied, both with 18 students. This article describes a study developing and incorporating CT modules and assessing their effect on the comprehension of CT principles by preservation teachers as well as their computing attitude. The results show that the implementation of analytical thought in education courses will successfully affect the comprehension of CT principles by preservice students.

Monitoring Liver Tumor Ablation with MR Spectroscopy of Extracellular pH.

HomeRadiology: Imaging CancerVol. 2, No. 2 PreviousNext Research HighlightsFree AccessMonitoring Liver Tumor Ablation with MR Spectroscopy of Extracellular pHGary D. LukerGary D. LukerGary D. LukerPublished Online:Mar 27 2020https://doi.org/10.1148/rycan.2020204007MoreSectionsPDF ToolsImage ViewerAdd to favoritesCiteTrack CitationsPermissionsReprints ShareShare onFacebookTwitterLinked InEmail Take-Away Points■ Major Focus: To monitor response of hepatocellular carcinoma to chemoembolization therapy using MR spectroscopy of extracellular pH.■ Key Result: Successful therapy reversed acidosis in liver tumors.■ Impact: Recovery of extracellular pH toward normal may provide a functional readout of treatment efficacy in hepatocellular carcinoma.Many patients with hepatocellular carcinoma cannot undergo surgical resection because of tumor size or concurrent medical problems. Transarterial chemoembolizaton (TACE) and other interventional ablation techniques offer alternatives for local control of disease, extending survival and potentially enabling surgical resection or liver transplantation. TACE alone typically fails to cause complete necrosis of hepatocellular carcinoma tumor nodules, motivating efforts to develop new imaging approaches to monitor response to therapy. Savic et al applied MR spectroscopy to noninvasively measure extracellular pH in liver tumors, using an established rabbit model of hepatocellular carcinoma. Hepatocellular carcinomas commonly utilize glycolysis to generate energy and a protumorigenic, immunosuppressive local environment. Glycolytic metabolism releases protons and lactate into the extracellular space, leading to reduced extracellular pH relative to adjacent normal liver tissue. As quantified by MR spectroscopy, TACE progressively reversed acidosis in the tumor environment, although values did not return completely to normal even in tumors with no pathologic evidence of residual disease. MR spectroscopy showed heterogeneous pH maps in incompletely treated tumors with areas of persistent acidic pH correlating with remaining viable tumor cells. The research team complemented MR spectroscopic data with multimodal MRI methods for cellularity (diffusion) and perfusion (contrast-enhanced T1-weighted images) combined with CT for distribution of lipiodol, a component of the TACE solution, in liver. Coregistered images showed similarities of lipiodol distribution, loss of cellularity, diminished perfusion, and reversal of acidic pH. Histologic analysis confirmed imaging data for tumor cellularity versus necrosis, vasculature, and reductions in markers of glycolytic metabolism. While the study included only preclinical animal models of therapy, the imaging methods could translate readily to clinical trials and applications. Combining MR spectroscopic mapping of extracellular pH as a marker of tumor metabolism with multimodal MRI and CT methods offers a highly promising, clinically translatable approach to monitor local ablation therapies used for hepatocellular carcinoma and likely other solid tumors.Highlighted ArticleSavic LJ, Schobert IT, Peters D, et al. Molecular imaging of extracellular tumor pH to reveal effects of locoregional therapy on liver cancer microenvironment. Clin Cancer Res 2020;26:428-438. doi: 10.1158/1078-0432.CCR-19-1702Highlighted ArticleSavic LJ, Schobert IT, Peters D, et al. Molecular imaging of extracellular tumor pH to reveal effects of locoregional therapy on liver cancer microenvironment. Clin Cancer Res 2020;26:428-438. doi: 10.1158/1078-0432.CCR-19-1702 Crossref, Medline, Google ScholarArticle HistoryPublished online: Mar 27 2020 FiguresReferencesRelatedDetailsRecommended Articles TACE Treatment in Patients with Sorafenib-treated Unresectable Hepatocellular Carcinoma in Clinical Practice: Final Analysis of GIDEONRadiology2016Volume: 279Issue: 2pp. 630-640Ablative Chemoembolization for Hepatocellular Carcinoma: A Prospective Phase I Case-Control Comparison with Conventional ChemoembolizationRadiology2017Volume: 287Issue: 1pp. 340-348Lack of Response to Transarterial Chemoembolization for Intermediate-Stage Hepatocellular Carcinoma: Abandon or Repeat?Radiology2021Volume: 298Issue: 3pp. 680-692Ischemia Induces Quiescence and Autophagy Dependence in Hepatocellular CarcinomaRadiology2017Volume: 283Issue: 3pp. 702-710MRI Assessment of Hepatocellular Carcinoma after Local-Regional Therapy: A Comprehensive ReviewRadiology: Imaging Cancer2020Volume: 2Issue: 1See More RSNA Education Exhibits Common Patterns of Change in ADC Histogram of Hepatocellular Carcinoma Lesions Following Transarterial Chemoembolization and Their Relationship with Patients’ PrognosisDigital Posters2019The Fast and the Furious: Rapid Progression of HCC After Locoregional Therapy — A Tri-Institutional Collaboration on Imaging PatternsDigital Posters2018A Practical Guide of Locoregional Treatment for Patients with Hepatocellular CarcinomaDigital Posters2019 RSNA Case Collection Hepatic AdenomatosisRSNA Case Collection2021Radioembolization of Liver Metastasis RSNA Case Collection2020Hepatic AngiosarcomaRSNA Case Collection2021 Vol. 2, No. 2 Metrics Downloaded 259 times Altmetric Score

MicroRNA-181a-3p as a Diagnostic and Prognostic Biomarker for Acute Myeloid Leukemia.

BackgroundMicro (mi) RNAs play an important role in the pathogenesis and development of acute myeloid leukemia (AML), and their abnormal expression may be sufficient to predict the prognosis and outcomes in AML patients. We evaluated the clinical diagnostic value of miRNA-181a-3p in predicting prognosis and outcomes in patients with AML.MethodsA total of 119 newly diagnosed adult patients with AML and 60 healthy controls were recruited. Blood specimens were obtained from all AML patients at diagnosis, and 10 blood specimens were obtained on day 28 after induction chemotherapy. The controls also provided blood samples. Relative gene expression was quantified by PCR and determined using the comparative Ct method. Publicly available clinical data and gene expressions for 188 patients with AML were downloaded from TCGA data portal.ResultsCompared with healthy controls, the expression of miRNA-181a-3p was significantly increased in patients with AML. MiR-181a-3p expression could be used to discriminate AML patients from controls, with up-regulated expression correlating with favorable prognosis. Moreover, miRNA-181a-3p expression was significantly decreased in patients who achieved a complete response after induction chemotherapy. The multivariate Cox analysis highlighted the prognostic value of miR-181a-3p for patients with AML. Finally, we found that miR-181a-3p expression was negatively correlated with the expression of the NF-κB essential modulator (NEMO/IKBKG).ConclusionsMiR-181a-3p may be clinically useful as a disease marker for AML, and enhanced the prediction of patient outcomes to chemotherapy.

Selection and validation of miR-1280 as a suitable endogenous normalizer for qRT-PCR Analysis of serum microRNA expression in Hepatocellular Carcinoma

Normalization procedures for the qRT-PCR analysis of miRNA in biological samples are recommended to reduce the variability caused by pre-analytical factors. Since there is no universal standardized normalization strategy for miRNA qRT-PCR studies, we conducted a throughout study to evaluate a panel of small non-coding RNAs (sncRNAs) as reference gene candidate for biomarker studies in serum samples of patients with hepatocellular carcinoma (HCC). Five sncRNAs (miR-1280, miR-1275, SNORD-116, SNORD-68, and U6) were chosen as candidate of reference genes. This study included 122 patients with HCC and was organized into a “pilot phase” consisting of 20 serum samples of HCC patients, and a “validation phase” of 102 patients. Expression level of these candidates were analyzed by qRT-PCR. Assessment of gene stability was performed using four different integrative platforms (geNorm NormFinder, Bestkeeper, and the Delta Ct method). To determine the gene stability during the follow-up of the patient, we extend the analysis of the validation cohort at T1 (1 month after treatment) and T2 (6 month after treatment). MiR-1280 was identified as the most stably expressed reference gene in both pilot and validation phase also during the follow-up. MiR-1280 appears a reliable reference gene candidate in biomarker studies.

Low-dose CT-based implant motion analysis is a precise tool for early migration measurements of hip cups: a clinical study of 24 patients

Background and purpose — Early implant migration is known to be a predictive factor of clinical loosening in total hip arthroplasty (THA). Radiostereometric analysis (RSA) is the gold standard used to measure early migration in patients. However, RSA requires costly, specialized imaging equipment and the image process is complex. We determined the precision of an alternative, commercially available, CT method in 3 ongoing clinical THA studies, comprising 3 different cups.Materials and methods — 24 CT double examinations of 24 hip cups were selected consecutively from 3 ongoing prospective studies: 2 primary THA (1 cemented and 1 uncemented) and 1 THA (cemented) revision study. Precision of the CT-based implant motion analysis (CTMA) system was calculated separately for each study, using both the surface anatomy of the pelvis and metal beads placed in the pelvis.Results — For the CTMA analysis using the surface anatomy of the pelvis, the precision ranged between 0.07 and 0.31 mm in translation and 0.20° and 0.39° for rotation, respectively. For the CTMA analysis using beads the precision ranged between 0.08 and 0.20 mm in translation and between 0.20° and 0.43° for rotations. The radiation dose ranged between 0.2 and 2.3 mSv.Interpretation — CTMA achieved a clinically relevant and consistent precision between the 3 different hip cups studied. The use of different hip cup types, different CT scanners, or registration method (beads or surface anatomy) had no discernible effect on precision. Therefore, CTMA without the use of bone markers could potentially be an alternative to RSA to measure early migration.

Fast binary CT using Fourier null space regularization (FNSR)

X-ray CT is increasingly being adopted in manufacturing as a non destructive inspection tool. Traditionally, industrial workflows follow a two step procedure of reconstruction followed by segmentation. Such workflows suffer from two main problems: (1) the reconstruction typically requires thousands of projections leading to increased data acquisition times. (2) The application of the segmentation process a posteriori is dependent on the quality of the original reconstruction and often does not preserve data fidelity. We present a fast iterative x-ray CT method which simultaneously reconstructs and segments an image from a limited number of projections called Fourier null space regularization (FNSR). The novelty of the approach is in the explicit updating of the image null space with values derived from a regularized image from the previous iteration, thus compensating for any missing projections and effectively regularizing the reconstruction. The speed of the method is achieved by directly applying the Fourier Slice Theorem where the non-uniform fast Fourier transform (NUFFT) is used to compute the frequency spectrum of the projections at their positions in the image k-space. At each iteration a segmented image is computed which is used to populate the null values of the image k-space effectively steering the reconstruction towards a binary solution. The effectiveness of the method to generate accurate reconstructions is demonstrated and benchmarked against other iterative reconstruction techniques using a series of numerical examples. Finally, FNSR is validated using industrial x-ray CT data where accurate reconstructions were achieved with 18 or more projections, a significant reduction from the 5000 needed by filtered back projection.

Potential Role of Macrophage Migration Inhibitory Factor in the Pathogenesis of Marek's Disease.

IntroductionMarek’s disease virus (MDV) can cause malignant T-cell lymphomas and immunosuppression in chickens. Macrophage migration inhibitory factor (MIF) not only plays a critical role in inhibiting T-cell responses, but also contributes to multiple aspects of tumour progression. The aim of this study was to reveal the potential role of MIF in the pathogenesis of MDV infection.Material and MethodsMIF gene expression levels were measured by using real-time PCR. Expression was assayed at different times in chicken embryo fibroblast (CEF) cells and tissue samples of SPF chickens infected with different MDV strains and fold change was calculated by the 2–△△CT method.ResultsThe expression of MIF was significantly downregulated (p < 0.05 and FC > 2) in CEF cells infected with the very virulent MDV RB1B strain at 48 h post infection (hpi) and in the skin and spleen at 14 days post infection (dpi). The reduction of MIF expression was also found in CEF cells infected by reticuloendotheliosis virus (REV), avian leukosis virus subgroup J (ALV-J), and MDV vaccine strain CVI988 or in HD11 cells stimulated with TLR2, 3, 4, and 7 ligands. Interestingly, MIF expression decreased continuously from 7 to 28 dpi in the thymus after RB1B virus infection while it increased after CVI988 virus infection. Upregulated expression of MIF was found in CEF infected with RB1B at 96 hpi and in the spleen and skin at 21 and 28 dpi.ConclusionThe present study revealed the different expression pattern of MIF in response to MDV infection and indicated that MIF level may be associated with MDV pathogenesis.

EFFECT OF PULSED MAGNETIC FIELDS ON THE EXPRESSION LEVELS OF TUMOR SUPPRESSOR GENES IN HUMAN T98G GLYOBLASTOMA CELL LINE

Aim: to study the effect of a pulsed magnetic field (PMF) on the expression of key tumor suppressor genes, such as aPc, MLH, and MGMt in human t98G glioblastoma cell line. material and methods . the PMF with the intensity of 15 and 300 mt was used alone and in combination with ionizing radiation at a single dose of 10 Gy. to perform ionizing radiation, theratron Equinox 60 co unit Best theratronics Ltd., Ottawa, canada) was used. the source of the pulsed magnetic field was Neuro-Ms / D therapeutic advanced device of the Neurosoft company. Live and dead cells were determined in NanoEntekJuliFl cell counter (Korea) using a 0.4 % trypan blue solution to stain dead cells. total RNa was extracted according to the protocol of the manufacturer trizol with changes: the aqueous phase was separated with trizol reagent twice. the quantitative measurement of the isolated RNa was carried out on a Qubit 2.0 fluorimeter using a kit of reagents with the Quant-it RNa assayKit RNa intercalating dye (Life technologies, usa). the expression of MLH, aPc, and MGMt genes was evaluated by Rt-PcR using a cFx96 amplifier (BioRad, usa). Data were analyzed using the cycle threshold (ct) method with normalization for tBP gene expression in each sample. Relative expression of the genetic locus (Exp) was calculated by the 2-Δct method. statistical analysis of the results was carried out using the statictica v10 software package. Results . One day after exposure to PMF, significant differences in the MGMt expression level compared to the control were found (p<0.05). a significant decrease in the transcriptional activity of the MGMt gene in glioblastoma cells was observed with PMF intensity of 15 mt, and correlated with the cell mortality rate. No changes in the mortality rate were observed after radiation exposure combined with 15 mt PMF. However, the mortality rate decreased from 18.7 % to 15 % after radiation exposure combined with 300 mt PMF. Conclusion . the effect of reduction in the transcriptional activity of MGMt in t98G glioblastoma cells and the effect of PMF as a monofactor on their viability characterize the magnetic susceptibility of tumor cell mechanisms. Given the multidirectional nature of the combined interaction of ionizing radiation and PMF, it is necessary to emphasize the importance of choosing and justifying the role of biotropic parameters of PMF in order to exclude a negative effect on the treatment.

Accurate segmentation method of liver tumor CT based on the combination of deep learning and radiomics

Accurate segmentation method of liver tumor CT based on the combination of deep learning and radiomics

基于CT及数字图像相关法的混凝土变形场测量分析

基于CT及数字图像相关法的混凝土变形场测量分析

Orbital venous varices: modern diagnostic methods and differential diagnosis

To study the possibility of the modern CT and MRI methods in diagnostics of the orbital venous varices (OVV), discover the special characteristics of these lesions concerning their hemodynamic and differential diagnosis with other orbital lesions. In the period from 2012 to 2019 ten patients with OVV were evaluated. Four of them were men, three - women and three - children (boys aged 7, 10, and 12 years). Age of the patients varied from 7 to 75 years old (mediana - 34). The majority of the OVV was localized in the medial compartments and apex of the orbit. Left sided lesions were found in 6 cases, right - 3. One patient had both sided OVV. In one of the cases in 10-year-old child, we revealed malformation of the Galen vein associated with bilateral varicose enlargement of the intraorbital veins (secondary OVV). Diagnosis of orbital vascular pathology requires an understanding of the classification of vascular lesions, the integration of the patient's medical history with epidemiological data, as well as a through analysis of the results of instrumental diagnostic methods. CT or MRI, including scanning in the prone position, as well as minimally invasive CT- and MR-TRICKS-angiography and ophthalmological studies of the patient, determine a comprehensive approach to the diagnosis and selection of adequate treatment for orbital venous varices.

Mitochondrial DNA content in tumor tissue and blood of patients with glioblastoma – A reliable biomarker?

Introduction: Recent studies have shown that mitochondrial DNA (mtDNA) content in the tumor tissue is associated with patient survival in glioblastoma (GBM). However, mtDNA content in the blood of patients with GBM and its variation during treatment has not been documented. Hence, we assessed mtDNA content in blood and tumor tissue of GBM patients, its association with survival, and the variation of mtDNA content in blood with treatment. Materials and Methods: GBM tissue obtained from 20 patients, 2 ml blood collected from the same patients at the time of presentation and following radiation therapy (RT), 2 ml blood obtained from 20 healthy volunteers were assessed for mtDNA content using quantitative real-time polymerase chain reaction (comparative ct method). The mtDNA content is expressed as the mtDNA/nuclear gene ratio. Results: The mean mtDNA copy number in the GBM tissue was 492.3819, while in the blood of patients, it was 41.76 ± 19.45. In healthy volunteers' blood, it was 55.97 ± 5.78 (P = 0.04). The median overall survival was 13 months in patients with high tumor mtDNA content and 10 months in patients with low tumor mtDNA content (P = 0.04). Patients with low-mtDNA content in the blood had a relatively higher content in the tumor tissue (correlation coefficient − 0.26; P = 0.27). No significant difference was noted between mtDNA content in preoperative blood (41.76 ± 19.45) and post-RT blood sample (44.16 ± 12.83) (P = 0.6). Conclusion: High GBM tumor mtDNA copy number is associated with better overall survival. mtDNA content in the blood is lower in GBM patients when compared with healthy volunteers. mtDNA content in the blood of the patients did not vary following surgery and RT.

18S rRNA, a potential reference gene in the qRT-PCR measurement of bisphenol A contamination in green mussels (Perna viridis) collected from the Gulf of Thailand

Normalization of reference genes through the selection of appropriate housekeeping genes is important for the reliable quantification of mRNA analyzed using real-time polymerase chain reaction (qRT-PCR). The suitability of various housekeeping genes (HKGs), were valuated as internal references to verify the levels of the contaminant bisphenol A (BPA, 2,2-bis (4-hydroxyphenyl) propane) by determining the level of gene expression of cytochrome P450 4 (cyp4) within the digestive gland of green mussels (Perna viridis)—a species used for biomonitoring environmental levels. Additionally, the effect was explored of mussel gender and maturity status (juvenile or mature) on the stability of the expression of the reference genes. Three candidate HKGs were examined, namely 18S rRNA, 28S rRNA and β-actin. The expression stability was calculated using three statistical approaches—NormFinder, BestKeeper and a comparative threshold cycle (Ct) method. The study found that of the three candidate reference genes, 28S rRNA and 18S rRNA were the most stable with no significant differences when maturity, gender and exposure to BPA were considered. It was noted that when these genes (18S rRNA, 28S rRNA, β-actin) were used for normalization using animals exposed to 10 ng BPA and the qRT-PCR method, different levels of cyp4 expression were observed. However, BPA significantly decreased the expression levels of cyp4 compared to the control (animals not exposed to BPA), only when 18S rRNA was used as an internal reference. These results highlighted the importance of selecting appropriate reference genes as the endogenous control in qRT-PCR in biomonitoring programs of BPA.