Identical Quality Assurance for Volumetric Modulated Arc Therapy in Elekta and Varian Machines

Volumetric modulated arc therapy (VMAT) has been adopted by many clinics for its higher delivery efficiency compared to conventional intensity modulated radiotherapy techniques. Currently, the quality assurance (QA) has remained a challenge in that no identical tests are available for accelerators from different vendors. This study is the first attempt to design identical QA tests for the VMAT technique for Varian and Elekta machines. Identical procedures testing MLC positions and movements, dose rate variations, and gantry positions and movement were created for both machines. These included picket fence (PF), dose rate vs. gantry speed (DRGS) and MLC speed vs. dose rate (MLCDR) tests. Deliverable plans for these tests were made with in-house software that was deliverable for linacs from two vendors (Elekta Synergy and Varian Trilogy). The electronic portal imaging device (EPID) was used for these tests. An automated analysis method was established and software was created to quantitatively evaluate the result. The systematic gap position and width errors from PF tests were within 0.5 mm. We evaluated the detectability of this program for introduced errors down to 0.2 mm. Linear relationships existed between the introduced errors and measured errors. In the DRGS test, 99.8% and 100.0% of the intensity deviations from expected profiles were less than 3% for the Synergy and Trilogy, respectively. For the MLCDR, the intensity deviations from expected profiles less than 3% were 100.0% for Synergy and 98.1% for Trilogy. Identical test series were created and implemented for VMAT accelerators from two vendors. Test results were reported from both accelerators. Comparable results were obtained from both vendors, enabling uniform criteria to be established for VMAT quality assurance.

Comparison of long-term and short-term administration of itraconazole for primary antifungal prophylaxis in recipients of allogeneic hematopoietic stem cell transplantation: a multicenter, randomized, open-label trial

BACKGROUND

The optimal agents and duration of primary antifungal prophylaxis in recipients of allogeneic hematopoietic stem cell transplantation (allo-HSCT) remain a matter of discussion.

OBJECTIVE

Our objective was to compare the efficacy and safety of long-term and short-term administration of itraconazole (ITCZ) for primary antifungal prophylaxis in allo-HSCT recipients.

METHODS

This multicenter, randomized, open-label pilot study was performed in 4 transplant centers in China. Recipients of allo-HSCT without a history of invasive fungal disease (IFD) were randomly assigned to the long-term or the short-term arm. Randomization was carried out by a center computer system. Intravenous ITCZ was given to the patients in both study arms with a loading dose of 400 mg/day for 2 days followed by 200 mg/day until day +14 or when the white blood cell count was >1.0 × 10(9) /L, and then switched to oral ITCZ solution; prophylaxis was continued until day +30 post transplantation in the short-term arm or until day +90 in the long-term arm. The trough serum concentrations of ITCZ also were measured. The primary study endpoint was the incidence of IFD (proven, probable, and possible) within day +90 post transplantation.

RESULTS

A total of 128 recipients were enrolled in this study; 59 of them were randomized to the long-term arm and 62 were randomized to the short-term arm, forming the modified intent-to-treat (mITT) set. The incidence of IFD within day +90, the primary endpoint, was not significantly different between the 2 arms for the mITT set (6.78% in the long-term arm vs. 6.45% in the short-term arm, P = 0.94), or for the per-protocol set (6.90% in the long-term arm vs. 6.67% in the short-term arm, P = 0.96). From day +30 to day +90, the incidence of IFD was 0% and 6.45%, respectively, in the patients with long-term and short-term prophylaxis for the mITT set (P = 0.11). The mean trough serum concentrations of ITCZ was maintained at >500 ng/mL throughout administration. The incidences of withdrawal because of drug-related adverse events in patients with long-term and short-term prophylaxis were 6.78% and 0%, respectively (P = 0.05).

CONCLUSIONS

Long-term and short-term administration of ITCZ both seemed effective in preventing IFD in recipients of allo-HSCT. Further study with large sample size should be performed to evaluate this result. ITCZ shows the same pharmacokinetics in recipients of allo-HSCT as in non-recipients.

Nanoscale adhesion forces between enamel pellicle proteins and hydroxyapatite

The acquired enamel pellicle (AEP) is important for minimizing the abrasion caused by parafunctional conditions as they occur, for instance, during bruxism. It is a remarkable feature of the AEP that a protein/peptide film can provide enough protection in normofunction to prevent teeth from abrasion and wear. Despite its obvious critical role in the protection of tooth surfaces, the essential adhesion features of AEP proteins on the enamel surface are poorly characterized. The objective of this study was to measure the adhesion force between histatin 5, a primary AEP component, and hydroxyapatite (HA) surfaces. Both biotinylated histatin 5 and biotinylated human serum albumin were allowed to adsorb to streptavidin-coated silica microspheres attached to atomic force microscope (AFM) cantilevers. A multimode AFM with a Nanoscope IIIa controller was used to measure the adhesion force between protein-functionalized silica microspheres attached to cantilever tips and the HA surface. The imaging was performed in tapping mode with a Si3N4 AFM cantilever, while the adhesion forces were measured in AFM contact mode. A collection of force-distance curves (~3,000/replicate) was obtained to generate histograms from which the adhesion forces between histatin 5 or albumin and the HA surface were measured. We found that histatin 5 exhibited stronger adhesion forces (90% >1.830 nN) to the HA surface than did albumin (90% > 0.282 nN). This study presents an objective approach to adhesion force measurements between histatin 5 and HA, and provides the experimental basis for measuring the same parameters for other AEP constituents. Such knowledge will help in the design of synthetic proteins and peptides with preventive and therapeutic benefits for tooth enamel.

The expression of cyclooxygenase-2 and vascular endothelial growth factor in the endometrium during the peri-implantation period in women with and without polyps

OBJECTIVE

This prospective study was designed to determine whether the expression of cyclooxygenase-2 (COX-2) and vascular endothelial growth factor (VEGF) in the endometrial tissue obtained from the peri-implantation period of women with endometrial polyp (EP) differs from that of control subjects without a polyp.

METHODS

Endometrial samples were collected from 30 patients with EP and 30 control subjects without EP, in the mid-secretory phase. The expression of COX-2 and VEGF in the endometrium was examined with the use of immunohistochemistry.

RESULTS

COX-2 and VEGF were predominantly expressed in endometrial glands. The expression of COX-2 and VEGF in the endometrium obtained from women with EP was lower than that of control subjects.

CONCLUSION

The reduced expression of COX-2 and VEGF in the endometrium of women with EP may account for the association between EP and infertility.

Magnetic, magnetocaloric and magnetoresistive properties of cubic Laves phase HoAl2 single crystal

We report the magnetization (M) and magnetoresistance (MR) results of HoAl2 single crystals oriented along the ⟨100⟩ and ⟨110⟩ directions. Although HoAl2 has cubic Laves phase structure, a large anisotropy is observed in M and MR below the Curie temperature (TC). A satisfactory correlation between magnetic entropy change (ΔSM) and MR could be established along ⟨110⟩ and also ⟨100⟩, except for the temperature (T) region around which spin reorientation takes place. Large inverse magnetocaloric effect is observed at low T, which is associated with the spin reorientation process in the ⟨100⟩ direction. A theoretical model based on the Landau theory of phase transition can describe the T-variation of -ΔSM for T > TC.

Rapid operation assessment of voluntary HIV counselling and testing services in three cities in China, 2009

OBJECTIVES

To assess the operation of voluntary counselling and testing (VCT) services forhuman immunodeficiency virus (HIV) in three cities in China.

STUDY DESIGN

A cross-sectional study using mixed methods, including focus group discussions,in-depth interviews, field assessment, archive checking and structured questionnaire interviews, was conducted to assess different aspects of VCT services.

METHODS

Surveys were undertaken in six counties of three China Global Fund AIDS Program (Round Five) cities, including 11 VCT clinics, 38 counsellors, 83 clients and 332 individuals at risk for HIV infection.

RESULTS

All counsellors were trained and approved for providing counselling. As there were adequate numbers of clinics and counsellors, VCT services ran smoothly. Clients were generally satisfied with VCT services and considered service operation to be adequate. Problems with the VCT programme included fewer VCT services in general hospitals, lack of a referral mechanism, and long delays between testing and receipt of results.

CONCLUSIONS

The operation of VCT services in the three cities was generally adequate, but referral services were poor. More attention needs to be paid to HIV testing and counselling in general hospitals, and referral networks need to be strengthened.

Biochip analysis of prostate cancer

Microarray expression analysis was used to forecast the roles of differentially co-expressed genes (DCG) and DCG and links in the pathogenesis of prostate cancer. In addition, we demonstrate that the relationship between transcriptional factors (TFs) and their targets can be considered a key factor in determining the difference between primary and metastatic prostate cancer. Regulatory impact factors were adopted to calculate the impact of TF. We identified 5 TFs and 29 target genes important in the transition between normal prostate and primary prostate cancer and 2 TFs and 7 target genes important in the transition between primary and metastatic prostate cancer. These results suggest that it may be possible to predict the clinical behavior of prostate cancer based on gene expression analysis.

Biomass density and filament length synergistically affect activated sludge settling: systematic quantification and modeling

Settling of the biomass produced during biological treatment of wastewater is a critical and often problematic process. Filamentous bacteria content is the best-known factor affecting biomass settleability in activated sludge wastewater treatment systems, and varying biomass density has recently been shown to play an important role as well. The objective of this study was to systematically determine how filament content and biomass density combine to affect microbial biomass settling, with a focus on density variations over the range found in full-scale systems. A laboratory-scale bioreactor system was operated to produce biomass with a range of filamentous bacterium contents. Biomass density was systematically varied in samples from this system by addition of synthetic microspheres to allow separation of filament content and density effects on settleability. Fluorescent in-situ hybridization indicated that the culture was dominated by Sphaerotilus natans, a common contributor to poor settling in full-scale systems. A simple, image-based metric of filament content (filament length per floc area) was linearly correlated with the more commonly used filament length per dry biomass measurement. A non-linear, semi-empirical model of settleability as a function of filament content and density was developed and evaluated, providing a better understanding of how these two parameters combine to affect settleability. Filament content (length per dry biomass weight) was nearly linearly related to sludge volume index (SVI) values, with a slightly decreasing differential, and biomass density exhibited an asymptotic relationship with SVI. The filament content associated with bulking was shown to be a function of biomass density. The marginal effect of filament content on settleability increased with decreasing biomass density (low density biomass was more sensitive to changes in filament content than was high density biomass), indicating a synergistic relationship between these factors. Consideration of both biomass density and filament content, as by the methods and model described herein, should improve operation and troubleshooting of settling processes for biological solids.

Photophysical, amplified spontaneous emission and charge transport properties of oligofluorene derivatives in thin films

We investigate the charge transport, photophysical and amplified spontaneous emission properties of a series of monodisperse solution-processable oligofluorenes functionalized with hexyl chains at the C9 position of each fluorene unit.

Diagnostic values of carcinoembryonic antigen in predicting peritoneal recurrence after curative resection of gastric cancer: a meta-analysis

AIM

A meta-analysis was performed to assess the diagnostic values of carcinoembryonic antigen (CEA) in predicting the peritoneal recurrence after curative resection of gastric cancer.

METHODS

The Medline, Embase, Web of Science, Ovid and Cochrane databases, Google Scholar and Vivisimo engines were searched to identify studies reporting on the accuracy of CEA protein or CEA mRNA in predicting the postoperative peritoneal recurrence of gastric cancer. Publication bias was demonstrated by Funnel plots and Egger test. The sensitivity, specificity, and diagnostic odds ratio (DOR) were calculated and summary receiver operating characteristic curves were generated.

RESULTS

Seven and eight studies fulfilled the inclusion criteria for CEA protein and mRNA determination, including 635 and 849 patients, respectively. The pooled sensitivity, specificity and DOR of CEA protein for predicting the peritoneal recurrence were 0.77 (95 % CI 0.69-0.84), 0.89 (95 % CI 0.86-0.92), 29.71 (95 % CI 10.27-85.92), respectively. Similarly, the values for CEA mRNA were 0.82 (95 % CI 0.75-0.88), 0.82 (95 % CI 0.79-0.85) and 22.97 (95 % CI 10.90-48.41). Meanwhile, the sensitivity and DOR of CEA protein or mRNA were higher than those of cytology, while higher specificity was noted in cytology assay.

CONCLUSION

CEA protein and mRNA levels in peritoneal lavage show a high diagnostic accuracy and may help accurately predict the peritoneal recurrence after curative resection of gastric cancer.

Screening of feature genes of the renal cell carcinoma with DNA microarray

AIM

To investigate the underlying molecular mechanisms of renal cell carcinoma (RCC) by using the microarray expression profiles of normal kidney and RCC tissue for early diagnosis and treatment of RCC.

MATERIALS AND METHODS

The gene expression profile of GES781 was downloaded from Gene Expression Omnibus database, including including nine tissue samples of RCC tissues removed from nine patients and eight adjacent normal renal tissue samples. We identified the differentially expressed genes (DEGs) by Multtest package in R software. The screened DEGs were further analyzed by bioinformatics methods. Firstly, the comparison of the DEGs expression degree was performed by cluster analysis. Secondly, DAVID was used to perform functional analysis of up- and down- regulated genes and the protein-protein interaction (PPI) networks were constructed by prePPI. Finally, the pathways of genes in PPI networks were discovered by WebGestalt.

RESULTS

Compared with the control, we screened 648 down-regulated and 681 up-regulated DEGs. And the down- and up-regulated DEGs with maximum expression degree were UMOD (uromodulin) and FABP7 (fatty acid binding protein 7), respectively. There was significant difference in the gene expression between the normal kidney and RCC tissue. The up-regulated DEGs in RCC tissue were significantly related to the immune responses and the down-regulated DEGs were significantly related to the oxidation reduction. The most significant pathway in the PPI network of UMOD was cytokine-cytokine receptor interaction.

CONCLUSIONS

The screened DEGs have the potential to become candidate target molecules to monitor, diagnose and treat the RCC, and might be beneficial for the early diagnosis and medication control of RCC.

Autologous stem cell transplantation as the first-line treatment for peripheral T cell lymphoma: results of a comprehensive meta-analysis

OBJECTIVE

In view of the poor prognosis of most peripheral T cell lymphoma (PTCL) subtypes treated with conventional chemotherapy such as CHOP/CHOP-like regimens, high-dose chemotherapy followed by autologous stem cell transplantation (HDT/ASCT) seems a reasonable option in eligible patients. Nevertheless, owing to the small size of the study and the heterogeneity of most published series, a consensus on the role of ASCT as the first-line consolidation therapy for high-risk PTCL patients has not been reached so far.

STUDY DESIGN

We searched MEDLINE, EMBASE, EBSCO, Web of Science, clinicaltrials.gov and the Cochrane Library. Hazard ratio (HR) and 95% confidence intervals (CIs) were calculated by a fixed/random effect model.

RESULTS

Twenty-one studies were eligible. Although no statistical significance was observed in these studies, there was a trend toward survival advantage for the HDT/ASCT group as compared to the historical control group (HR 0.81, 95% CI 0.31-2.13). Statistical differences were confirmed in terms of overall survival (OS) between complete remission (CR) and non-CR patients (HR 3.17, 95% CI 0.92-5.42), patients with good and poor risk according to the International Prognostic Index (IPI; HR 0.36, 95% CI 0.22-0.60, I(2) 49%) and Prognostic Index for PTCL (PIT; HR 0.31, 95% CI 0.17-0.58; HR 0.31, 95% CI 0.18-0.54).

CONCLUSION

The clear and convincing proof of the effects of up-front HDT/ASCT still depends on sufficient large PTCL-restricted randomized trials in the future. Patients who failed to attain CR before transplant exhibited a worse prognosis; patients with good risk of IPI or PIT had a substantially better OS after ASCT.