45 research outputs found

    Rectal dose sparing and prostate immobilization using a rectal balloon in the treatment of prostate cancer with dose escalation conformal radiation therapy

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    ABSTRACT Objective The use of conformal radiation therapy in the treatment of carcinoma of the prostate has allowed for dose escalation and improved local control. The dose to the rectum is an important consideration in determining complication rates. This study aims to evaluate the effect of a Foleys rectal catheter balloon on the dose volume histograms to the rectum and to assess the effect of the balloon catheter on prostate gland immobilization during treatment of intermediate risk cancer of the prostate. Design and methods Ten patients with intermediate risk prostate cancer, each acting as his own control, were recruited in the study; eight patients had complete data for analysis. CT scans were done at intervals during treatment, with and without a rectal balloon filled with 30 ml of contrast. 3 pairs of CT scans for each patient were performed and were available for analysis. All patients were treated with 6-field conformal radiotherapy up to 66 Gy followed by a boost of 12 Gy in 3 fractions to the prostate using a rectal balloon and a 3- field plan. Dose volume histograms were calculated for the boost plan with and without the rectal balloon. Movements of the prostate in the superior-inferior and the anteriorposterior directions were measured with and without the balloon for each treatment. There was a slight reduction in the dose received by 1% and 2 % of the rectal volume with the balloon (55% and 52% respectively), compared to without a balloon (57% and 54.3% respectively) (p> 0.05). Results There was a non significant increase in the dose received by 50% of the rectum (p>0.05) with the use of the rectal balloon due to the rectum being pushed towards the symphysis pubis by the balloon. With the use of rectal balloon, the superior / inferior displacement of the prostate was reduced (p=0.04) and a displacement of more than 5 mm was observed in one out of eight patients. The anterior / posterior displacement of the prostate was decreased with the rectal balloon with a mean of 4 mm compared to 5 mm with no rectal balloon. This was not statistically significantly (p>0.05). However, displacement of more than 5 mm was observed in 2 patients with the rectal balloon. No grade 3 acute rectal toxicity was recorded in the 8 patients. Conclusion There was no significant change in the percentage dose received by the rectum with the use of the rectal balloon in this study. The study showed however that the rectal balloon significantly reduced prostate movement during treatment

    Epigenetic and transcriptional signatures of stable versus plastic differentiation of proinflammatory gd T cell subsets

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    Two distinct subsets of γδ T cells that produce interleukin 17 (IL-17) (CD27(-) γδ T cells) or interferon-γ (IFN-γ) (CD27(+) γδ T cells) develop in the mouse thymus, but the molecular determinants of their functional potential in the periphery remain unknown. Here we conducted a genome-wide characterization of the methylation patterns of histone H3, along with analysis of mRNA encoding transcription factors, to identify the regulatory networks of peripheral IFN-γ-producing or IL-17-producing γδ T cell subsets in vivo. We found that CD27(+) γδ T cells were committed to the expression of Ifng but not Il17, whereas CD27(-) γδ T cells displayed permissive chromatin configurations at loci encoding both cytokines and their regulatory transcription factors and differentiated into cells that produced both IL-17 and IFN-γ in a tumor microenvironment

    Atrasentan and renal events in patients with type 2 diabetes and chronic kidney disease (SONAR): a double-blind, randomised, placebo-controlled trial

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    Background: Short-term treatment for people with type 2 diabetes using a low dose of the selective endothelin A receptor antagonist atrasentan reduces albuminuria without causing significant sodium retention. We report the long-term effects of treatment with atrasentan on major renal outcomes. Methods: We did this double-blind, randomised, placebo-controlled trial at 689 sites in 41 countries. We enrolled adults aged 18–85 years with type 2 diabetes, estimated glomerular filtration rate (eGFR)25–75 mL/min per 1·73 m 2 of body surface area, and a urine albumin-to-creatinine ratio (UACR)of 300–5000 mg/g who had received maximum labelled or tolerated renin–angiotensin system inhibition for at least 4 weeks. Participants were given atrasentan 0·75 mg orally daily during an enrichment period before random group assignment. Those with a UACR decrease of at least 30% with no substantial fluid retention during the enrichment period (responders)were included in the double-blind treatment period. Responders were randomly assigned to receive either atrasentan 0·75 mg orally daily or placebo. All patients and investigators were masked to treatment assignment. The primary endpoint was a composite of doubling of serum creatinine (sustained for ≥30 days)or end-stage kidney disease (eGFR <15 mL/min per 1·73 m 2 sustained for ≥90 days, chronic dialysis for ≥90 days, kidney transplantation, or death from kidney failure)in the intention-to-treat population of all responders. Safety was assessed in all patients who received at least one dose of their assigned study treatment. The study is registered with ClinicalTrials.gov, number NCT01858532. Findings: Between May 17, 2013, and July 13, 2017, 11 087 patients were screened; 5117 entered the enrichment period, and 4711 completed the enrichment period. Of these, 2648 patients were responders and were randomly assigned to the atrasentan group (n=1325)or placebo group (n=1323). Median follow-up was 2·2 years (IQR 1·4–2·9). 79 (6·0%)of 1325 patients in the atrasentan group and 105 (7·9%)of 1323 in the placebo group had a primary composite renal endpoint event (hazard ratio [HR]0·65 [95% CI 0·49–0·88]; p=0·0047). Fluid retention and anaemia adverse events, which have been previously attributed to endothelin receptor antagonists, were more frequent in the atrasentan group than in the placebo group. Hospital admission for heart failure occurred in 47 (3·5%)of 1325 patients in the atrasentan group and 34 (2·6%)of 1323 patients in the placebo group (HR 1·33 [95% CI 0·85–2·07]; p=0·208). 58 (4·4%)patients in the atrasentan group and 52 (3·9%)in the placebo group died (HR 1·09 [95% CI 0·75–1·59]; p=0·65). Interpretation: Atrasentan reduced the risk of renal events in patients with diabetes and chronic kidney disease who were selected to optimise efficacy and safety. These data support a potential role for selective endothelin receptor antagonists in protecting renal function in patients with type 2 diabetes at high risk of developing end-stage kidney disease. Funding: AbbVie

    Electron Transport in Correlated Thin Film Oxides

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    Medical micro/nanorobots in complex media

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    Medical micro/nanorobots have received tremendous attention over the past decades owing to their potential to be navigated into hard-to-reach tissues for a number of biomedical applications ranging from targeted drug/gene delivery, bio-isolation, detoxification, to nanosurgery. Despite the great promise, the majority of the past demonstrations are primarily under benchtop or in vitro conditions. Many developed micro/nanoscale propulsion mechanisms are based on the assumption of a homogeneous, Newtonian environment, while realistic biological environments are substantially more complex. Moving toward practical medical use, the field of micro/nanorobotics must overcome several major challenges including propulsion through complex media (such as blood, mucus, and vitreous) as well as deep tissue imaging and control in vivo. In this review article, we summarize the recent research efforts on investigating how various complexities in biological environments impact the propulsion of micro/nanoswimmers. We also highlight the emerging technological approaches to enhance the locomotion of micro/nanorobots in complex environments. The recent demonstrations of in vivo imaging, control and therapeutic medical applications of such micro/nanorobots are introduced. We envision that continuing materials and technological innovations through interdisciplinary collaborative efforts can bring us steps closer to the fantasy of “swallowing a surgeon”

    Medical micro/nanorobots in complex media

    No full text
    Medical micro/nanorobots have received tremendous attention over the past decades owing to their potential to be navigated into hard-to-reach tissues for a number of biomedical applications ranging from targeted drug/gene delivery, bio-isolation, detoxification, to nanosurgery. Despite the great promise, the majority of the past demonstrations are primarily under benchtop or in vitro conditions. Many developed micro/nanoscale propulsion mechanisms are based on the assumption of a homogeneous, Newtonian environment, while realistic biological environments are substantially more complex. Moving toward practical medical use, the field of micro/nanorobotics must overcome several major challenges including propulsion through complex media (such as blood, mucus, and vitreous) as well as deep tissue imaging and control in vivo. In this review article, we summarize the recent research efforts on investigating how various complexities in biological environments impact the propulsion of micro/nanoswimmers. We also highlight the emerging technological approaches to enhance the locomotion of micro/nanorobots in complex environments. The recent demonstrations of in vivo imaging, control and therapeutic medical applications of such micro/nanorobots are introduced. We envision that continuing materials and technological innovations through interdisciplinary collaborative efforts can bring us steps closer to the fantasy of “swallowing a surgeon”

    Hydrogen Isotope Separation within the Metal-Organic Framework Cu(I)-MFU-4l

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    Hydrogen isotope separation within the metal-organic framework material known as Cu(I)-MFU-4l is investigated using a combination of breakthrough analysis, equilibrium measurements, and infrared spectroscopy. Results confirm the expected large infrared frequency shift of the adsorbed H-2 vibrational mode and reveal an extremely high binding energy difference between H-2 and D-2 of 2.3 kJ/mol. Both static and dynamic measurements indicate that the material\u27s selectivity for D-2 over H-2 increases with decreasing temperature, reaching a maximum at approximate to 100 K, but then decreases for lower temperatures. These results indicate an activation barrier for the replacement of adsorbed H-2 by D-2 and place a limit on the material\u27s effectiveness for isotope separation at low temperature
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