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  • Author: Yang Yang x
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A method on theoretical simulation of chromosome breaks in cells exposed to heavy ions

A method on theoretical simulation of chromosome breaks in cells exposed to heavy ions

Background. The aim of this study is to assess an easy and quick method on simulating chromosome breaks in cells exposed to heavy charged particles.

Methods. The theoretical value of chromosome break was calculated, and the validated comparison with the experimental value by using a premature chromosome condensation technique was done.

Results. A good consistence was found to be appeared between the theoretical and experimental value.

Conclusions. This suggested that a higher relative biological effectiveness of heavy ions was closely correlated with its physical characteristics and besides, a safe approach on predicting chromosome breaks in cells exposed to heavy ions at off-line environment come to be considered. Furthermore, three key factors influencing the theoretical simulation was investigated and discussed.

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Analysis of peripheral artery velocity tracing in a porcine model

Analysis of peripheral artery velocity tracing in a porcine model

Background. The aim of the study was to trace the peripheral artery velocity with ultrasound in pigs and provide inference on diagnosis of the type, location and severity of vascular diseases.

Materials and methods. Limb tightening, adrenaline administration and arterial wall pinching were performed independently in six pigs, and then the evolution of the external iliac artery or femoral artery velocity tracing were monitored.

Results. With the increase of the extents of hindlimb tightening, peak systolic velocity (PSV) of ipsilateral external iliac artery turned from 36.33±1.77 cm/s to 59.72±2.67 cm/s, minimum post-principal wave velocity (MPV from 13.68±1.11 cm/s to -7.48±0.82 cm/s, peak diastolic velocity (PDV) from 19.31±0.86 cm/s to 8.98±0.45 cm/s, and, end diastolic velocity (EDV) from 13.2±0.45 cm/s to 0. With the increase of the dose of the epinephrine injection, PSV increased from 36.33±1.77 cm/s to 43.97±2.15 cm/s but then decreased to 35.43±3.01 cm/s, and MPV negatively increased to -23.53±0.82 cm/s after decreasing from 13.68±1.11 cm/s to 0. PDV and EDV gradually decreased to zero. With the increase of the stenosis severity in the abdominal aortic wall pinching, PSV was reduced and had a linearly negative correlation with the stenosis severity (R=0.983, R2=0.967). MPV gradually increased, and its direction reversed when the stenosis severity increased, then diminished when the blood flow was occluded by more than 2/3.

Conclusions. The formation of peripheral artery velocity is the result of concurrent effects of cardiac ejection, vascular resistance, effective circulating blood volume and elastic recoil. Vascular resistance exerts pronounced effects on the diastolic waveform, and the occurrence of backward wave indicates that the downstream circulation resistance significantly increases.

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Fluctuating portal velocity tracing with rhythmicity: ultrasonic differential diagnosis and clinical significance

Fluctuating portal velocity tracing with rhythmicity: ultrasonic differential diagnosis and clinical significance

Background. To evaluate the usefulness of the routine sonographic evaluation of the pattern of fluctuate portal velocity tracings and the hepatic veins for the diagnosis of arterioportal fistula (APF) and cardiogenic trans-sinusoidal shunting (CTS).

Materials and methods. Color Doppler flow imaging and pulsed-wave Doppler (PW) examinations of the portal vein were performed in 282 subjects. The waveforms of the velocity tracings in the portal main trunk and its branches were determined to infer APF or CTS. Suspected cases of APFs or CTSs were always confirmed by echocardiography, contrast-enhanced ultrasound, computed tomography, or digital subtraction angiography findings. The portal maximum velocity (V max), minimum velocity(V min), V max/V min, arterial peak systolic velocity and resistance index, and venous reverse and forward velocities were used to estimate their haemodynamics.

Results. The waveform of the velocity tracing for the draining portal vein of APF was typically arterial-like or diphase, as indicated by a systolic hepatofugal dwarf peak and a diastolic hepatopetal low flat shape. The flow in the affected portal vein was always hepatofugal in an intrahepatic patient, whereas a hepatopetal flow was observed in an extrahepatic APF patient. The waveform of the velocity tracing for the portal vein of CTS patients, especially its intrahepatic branches, showed a typical hump-like shape with or without a transitory hepatofugal tracing. The PW results displayed an increase in the retrograde phase of the hepatic venous flow with increased velocities in the two phases.

Conclusions. Portal velocity tracings should be evaluated during routine detecting for APF or CTS, especially in patients with gastrointestinal upsets.

Open access
Poor outcome of comprehensive therapy in a case of laryngeal synovial sarcoma

Background. Synovial sarcoma is common in the extremities. Our search revealed only 17 cases of synovial sarcoma of the larynx in the English-language literature.

Case report. We report an additional case of a 37-year-old man with primary laryngeal synovial sarcoma who underwent positron emission tomography/computed tomography (PET/CT) following the treatment. Although the patient received comprehensive therapy including surgery, radiotherapy, repeated chemotherapies, and targeted therapies, he had an unfavourable outcome and died of distant metastases.

Conclusions. In synovial sarcoma of the larynx, PET/CT can detect recurrence and metastasis. PET/CT can also predict the treatment effect in patients with synovial sarcoma.

Open access
Proteomic analysis of effects by x-rays and heavy ion in HeLa cells

Abstract

Background. Carbon ion therapy may be better against cancer than the effects of a photon beam. To investigate a biological advantage of carbon ion beam over X-rays, the radioresistant cell line HeLa cells were used. Radiationinduced changes in the biological processes were investigated post-irradiation at 1 h by a clinically relevant radiation dose (2 Gy X-ray and 2 Gy carbon beam). The differential expression proteins were collected for analysing biological effects.

Materials and methods. The radioresistant cell line Hela cells were used. In our study, the stable isotope labelling with amino acids (SILAC) method coupled with 2D-LC-LTQ Orbitrap mass spectrometry was applied to identity and quantify the differentially expressed proteins after irradiation. The Western blotting experiment was used to validate the data.

Results. A total of 123 and 155 significantly changed proteins were evaluated with treatment of 2 Gy carbon and X-rays after radiation 1 h, respectively. These deregulated proteins were found to be mainly involved in several kinds of metabolism processes through Gene Ontology (GO) enrichment analysis. The two groups perform different response to different types of irradiation.

Conclusions. The radioresistance of the cancer cells treated with 2 Gy X-rays irradiation may be largely due to glycolysis enhancement, while the greater killing effect of 2 Gy carbon may be due to unchanged glycolysis and decreased amino acid metabolism.

Open access
miR-548c-5p inhibits proliferation and migration and promotes apoptosis in CD90+ HepG2 cells

miR-548c-5p inhibits proliferation and migration and promotes apoptosis in CD90+ HepG2 cells

Background. Since the introduction of the theory of tumour stem cells (TSCs), the liver cancer stem cell (LCSC)-like cells have become one of the focuses in the research on liver cancer.

Materials and methods. In this study, CD90+ cells were applied as the possible LCSC-like cells, and the miRNA and gene expression were analyzed in the CD90+ HepG2 cells. The pilot study showed miR-548c-5p exerted potential effect on the CD90+ HepG2 cells and was thereafter applied for the further study. CD90+ HepG2 cells were assigned to miR-548c-5p mimic transfection group and control group. MTT assay was performed to detect the proliferation of CD90+ HepG2 cells. The migration and invasion abilities were examined by wound healing assay and transwell migration assay, respectively. A detection of apoptosis was performed by fluorescence microscopy.

Results. Our results showed that caspase-3 and bcl-2 were down-regulated while caspase-8 was up-regulated in the CD90+ HepG2 cells. Moreover, the miR-548c-5p transfection could down-regulate the expression of β-catenin, Tg737, bcl-2, bcl-XL, and caspase-3, inhibit the proliferation, migration and invasion and promote the apoptosis of the CD90+ HepG2 cells.

Conclusions. Our findings indicate the imbalance between apoptosis and anti-apoptosis in the LCSC-like cells, which influence the biological features of LCSC-like cells. miRNA plays a regulatory role in the LCSC-like cells among which miR-548c-5p might be a suppressor.

Open access
CT findings predict survival of patients with peripheral T cell lymphoma: a preliminary study

Abstract

Background

Peripheral T-cell lymphoma (PTCL) is an uncommon disease with poor clinical outcomes. Radiological reports on the survival of patients with PTCL are scarce. The purpose of this study is to investigate the prognostic value of CT findings to predict clinical outcomes in fifty-one patients with histologically proven PTCL.

Patients and methods

The clinical data and CT images of all patients were retrospectively reviewed. CT features including number of involvement sites, lesion size, shape, margin, density, peritumoral invasion, intratumoral necrosis, lymph node involvement, and degree of contrast enhancement were evaluated. Univariate and multiple logistic regression analysis were used to determine the association between the clinical outcome and radiologic factors.

Results

Multiple site involvement, an ill-defined margin with peritumoral invasion, inhomogeneous density, and intratumoral necrosis were found to be associated with poor outcomes in univariate analysis (P < 0.05). An ill-defined margin with peritumoral invasion, was identified as an independent risk sign by further multivariate logistic regression analysis (P < 0.05). The area under the ROC curve of this CT feature was 0.745 (P < 0.05).

Conclusions

An ill-defined margin with peritumoral invasion was a valuable prognostic factor to predict the worse clinical outcomes in patients with PTCL.

Open access
Treatment of nasopharyngeal carcinoma using simultaneous modulated accelerated radiation therapy via helical tomotherapy: a phase II study

Abstract

Background

The aim of the study was to evaluate short-term safety and efficacy of simultaneous modulated accelerated radiation therapy (SMART) delivered via helical tomotherapy in patients with nasopharyngeal carcinoma (NPC).

Methods

Between August 2011 and September 2013, 132 newly diagnosed NPC patients were enrolled for a prospective phase II study. The prescription doses delivered to the gross tumor volume (pGTVnx) and positive lymph nodes (pGTVnd), the high risk planning target volume (PTV1), and the low risk planning target volume (PTV2), were 67.5 Gy (2.25 Gy/F), 60 Gy (2.0 Gy/F), and 54 Gy (1.8 Gy/F), in 30 fractions, respectively. Acute toxicities were evaluated according to the established RTOG/EORTC criteria. This group of patients was compared with the 190 patients in the retrospective P70 study, who were treated between September 2004 and August 2009 with helical tomotherapy, with a dose of 70-74 Gy/33F/6.5W delivered to pGTVnx and pGTVnd.

Results

The median follow-up was 23.7 (12–38) months. Acute radiation related side-effects were mainly problems graded as 1 or 2. Only a small number of patients suffered from grade 4 leucopenia (4.5%) or thrombocytopenia (2.3%). The local relapse-free survival (LRFS), nodal relapse-free survival (NRFS), local-nodal relapse-free survival (LNRFS), distant metastasis-free survival (DMFS) and overall survival (OS) were 96.7%, 95.5%, 92.2%, 92.7% and 93.2%, at 2 years, respectively, with no significant difference compared with the P70 study.

Conclusions

Smart delivered via the helical tomotherapy technique appears to be associated with an acceptable acute toxicity profile and favorable short-term outcomes for patients with NPC. Long-term toxicities and patient outcomes are under investigation.

Open access
A population-based study of the effectiveness of stereotactic ablative radiotherapy versus conventional fractionated radiotherapy for clinical stage I non-small cell lung cancer patients

Abstract

Background

Stereotactic ablative radiotherapy (SABR) is a promising option for non-operated early-stage non-small cell lung cancer (NSCLC) compared to conventional fractionated radiotherapy (CFRT). However, results from conclusive randomized controlled trials are not yet available. The aim of our study was to explore the effectiveness of SABR vs. CFRT for non-operated early-stage NSCLC.

Patients and methods

We used a comprehensive population-based database to identify clinical stage I non-operated NSCLC patients in Taiwan diagnosed from 2007 to 2013 who were treated with either SABR or CFRT. We used inverse probability weighting and the propensity score as the primary form of analysis to address the nonrandomization of treatment. In the supplementary analyses, we constructed subgroups based on propensity score matching to compare survival between patients treated with SABR vs. CFRT.

Results

We identified 238 patients in our primary analysis. A good balance of covariates was achieved using the propensity score weighting. Overall survival (OS) was not significantly different between those treated with SABR vs. CFRT (SABR vs. CFRT: probability weighting adjusted hazard ratio [HR] 0.586, 95% confidence interval 0.264–1.101, p = 0.102). However, SABR was significantly favored in supplementary analyses.

Conclusions

In this population-based propensity-score adjusted analysis, we found that OS was not significantly different between those treated with SABR vs. CFRT in the primary analysis, although significance was observed in the supplementary analyses. Our results should be interpreted with caution given the database (i.e., nonrandomized) approach used in our study. Overall, further studies are required to explore these issues.

Open access
Accuracy of 18F-flurodeoxyglucosepositron emission tomography/computed tomography in the staging of newly diagnosed nasopharyngeal carcinoma: a systematic review and meta-analysis

Abstract

Background. The specific role of 18F-flurodeoxyglucose-positron emission tomography/computed tomography (FDG-PET/CT) in staging of nasopharyngeal carcinoma (NPC) remains to be validated. A systematic review and meta-analysis were performed to assess the accuracy of staging FDG-PET/CT for newly diagnosed NPC. Methods. We searched various biomedical databases and conference proceedings for relevant studies. We determined the pooled sensitivities and specificities, diagnostic odds ratios (DOR) and constructed summary receiver operating characteristic (SROC) curves using the hierarchical regression model. Results. 15 relevant studies including 851 patients were identified. Five addressed primary tumor (T), nine addressed regional lymph nodes (N) and seven addressed distant metastasis (M). The combined sensitivity estimate for FDG-PET/CT in T classification was 0.77 (95% confidence interval [CI] 0.59-0.95). For N classification, combined sensitivity was 0.84 (95% CI 0.76-0.91), specificity was 0.90 (95% CI 0.83-0.97), DOR was 82.4 (23.2-292.6) and Q*-index was 0.90. For M classification, the combined sensitivity estimate was 0.87 (95% CI 0.74-1.00), specificity was 0.98 (95% CI 0.96-1.00), DOR was 120.9 (43.0-340.0) and Q*-index was 0.89. Conclusion. FDG-PET/CT showed good accuracy in N and M but not T classification for newly diagnosed NPC. FDG-PET/CT, together with Magnetic resonance imaging (MRI) of the nasopharynx, should be part of the routine staging investigations

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