Gastrointestinal toxicities following radiation therapy for localized prostate cancer

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Background: Radiation therapy (RAD) is commonly employed to treat localized prostate cancer; however, representative data regarding treatment related toxicities compared to conservative management (CM) is sparse.

Methods: We performed a population-based cohort study, using Medicare claims data linked to the Surveillance, Epidemiology, and End Results data, to evaluate gastrointestinal (GI) toxicities in men aged 65-85 years treated with either primary RAD or CM for T1-T2 prostate cancer diagnosed in 1992-2005. In this study, only GI toxicities requiring interventional procedures occurring after 6 months of cancer diagnosis were included. Competing risk models were used with the following covariates: year of diagnosis, comorbidity, age, tumor stage, cancer grade, hormone use within 1 year of diagnosis, region, race, poverty and marital status.

Results: Among 41,859 patients in this study, 28,021 patients received radiation therapy, 19,287 with external beam radiation therapy (EBRT) alone, and 5,138 with brachytherapy alone. The most common GI toxicity was GI bleeding or ulceration. GI toxicity rates were 6.1% after 3D-conformal therapy (3D-CRT), 2.8% after intensity modulated radiation therapy (IMRT), 2.6% after brachytherapy, 8.2% after proton therapy and 1.1% for CM patients. In the multivariate models, RAD group was associated with a higher hazard of GI toxicities (hazard ratio [HR] 4.68; 95% CI, 3, 93-5.58) than CM. Comparing to 3D-CRT, brachytherapy (HR 0.62; 95% CI, 0.51-0.75) and IMRT (HR 0.67; 95% CI, 0.55-0.82) are associated with a lower hazard of GI toxicities, while proton therapy is associated with a higher hazard of GI toxicities (HR 2.15; 95% CI, 1.45-3.17).

Conclusions: Radiation therapy is associated with a higher risk of GI toxicities than CM. Among different modalities of radiation therapy, protons therapy is associated with the highest risk of GI toxicities, followed by 3D-CRT, IMRT, and brachytherapy. The increased GI toxicities for patients with proton therapy may reflect a learning curve in the early years.

No significant financial relationships to disclose.

Evaluation of low-cost cathode catalysts for high yield biohydrogen production in microbial electrolysis cell

As an ideal fuel due to the advantages of no pollution, high combustion heat and abundant sources, hydrogen gas can be produced from organic matter through the electrohydrogenesis process in microbial electrolysis cells. But in many MECs, platinum is often used as catalyst, which limits the practical applications of MECs. To reduce the cost of the MECs, Ni-based alloy cathodes were developed by electrodepositing. In this paper hydrogen production using Ni-W-P cathode was studied for the first time in a single-chamber membrane-free MEC. At an applied voltage of 0.9 V, MECs with Ni-W-P cathodes obtained a hydrogen production rate of 1.09 m3/m3/day with an cathodic hydrogen recovery of 74%, a Coulombic efficiency of 56% and an electrical energy efficiency relative to electrical input of 139%, which was the best result of reports in this study. The Ni-W-P cathode demonstrated a better electrocatalytic activity than the Ni-Ce-P cathode and achieved a comparable performance to the Pt cathode in terms of hydrogen production rate, Coulombic efficiency, cathodic hydrogen recovery and electrical energy efficiency at 0.9 V.

Trends and developments in bioinformatics in 2010: prospects and perspectives

OBJECTIVES

To survey major developments and trends in the field of Bioinformatics in 2010 and their relationships to those of previous years, with emphasis on long-term trends, on best practices, on quality of the science of informatics, and on quality of science as a function of informatics.

METHODS

A critical review of articles in the literature of Bioinformatics over the past year.

RESULTS

Our main results suggest that Bioinformatics continues to be a major catalyst for progress in Biology and Translational Medicine, as a consequence of new assaying technologies, most pre-dominantly Next Generation Sequencing, which are changing the landscape of modern biological and medical research. These assays critically depend on bioinformatics and have led to quick growth of corresponding informatics methods development. Clinical-grade molecular signatures are proliferating at a rapid rate. However, a highly publicized incident at a prominent university showed that deficiencies in informatics methods can lead to catastrophic consequences for important scientific projects. Developing evidence-driven protocols and best practices is greatly needed given how serious are the implications for the quality of translational and basic science.

CONCLUSIONS

Several exciting new methods have appeared over the past 18 months, that open new roads for progress in bioinformatics methods and their impact in biomedicine. At the same time, the range of open problems of great significance is extensive, ensuring the vitality of the field for many years to come.

The use of endoscopic ultrasound-guided gold markers in image-guided radiation therapy of pancreatic cancers: a case series

While endoscopic ultrasound (EUS)-guided fiducial placement is technically feasible, its role in the delivery of image-guided radiation therapy (IGRT) is unclear. In this study, we evaluated the feasibility and safety of using EUS-guided fiducial markers for delivering IGRT in patients with pancreatic cancer. Following computed tomography (CT) simulation, a radiation therapy treatment plan was prepared for each patient. A kilovoltage (kv) image obtained before each treatment session was aligned with images generated during treatment planning, based on the position of fiducials. Radiation therapy was then delivered. Image analysis was also performed by alignment of bony landmarks (current standard of care). Daily shifts of fiducials between the two sets of images represented movement of the pancreas relative to the bony landmarks. EUS-guided fiducial placement was technically successful in all nine patients and no complications were encountered. The fiducials were easily identified for image fusion and IGRT was delivered successfully to all patients. The movement of the pancreas relative to bones was 0.2 cm (0.1-0.5 cm), 0.5 cm (0.2-1.5 cm), and 0.4 cm (0.2-0.9 cm) in the anterior-posterior, superior-inferior, and left-right axes, respectively. This technique may have significant clinical implications in terms of radiation dosimetry.

Effectiveness of cross-linked phyllosilicates for intercalative immobilization of soybean lipoxygenase

A novel procedure was developed to intercalate enzymes into dispersed phyllosilicates that were cross-linked with silicate polymers formed by the hydrolysis of tetramethyl orthosilicate (TMOS). Lipoxygenase (LOX) intercalated into cross-linked phyllosilicates exhibited high enzymatic activity. The enzyme-phyllosilicate composite prepared by this procedure had an improved pore network. Alkylamines were used to occupy the charge sites of the phyllosilicate, which increased the hydrophobicity of the phyllosilicate and reduced charge-charge interaction between LOX and the phyllosilicate. The amount of macropores and the enzymatic activity of the lipoxygenase-phyllosilicate composites increased with an increase in the ratio of trimethylammonium (TMA)-phyllosilicate to cross-linking reagent TMOS. LOX intercalatively immobilized into phyllosilicates displayed good storage stability and reusability at ambient temperature.