44 research outputs found
The barefoot road
My novella is set in South Africa in a post-apocalyptic world. The drone technology theorised for the near future is widespread and scattered survivors live under the constant threat of drone strikes. The protagonist tries to negotiate these dangers and the looming threat of a slave empire to reconnect with his friends and family. He encounters bizarre hallucinations and flashbacks as a result of exposure to an unidentified gas
Post-Operative Extended Volume External Beam Radiation Therapy Is Safe for High Risk Esophageal Cancer Patients
Post-operative radiation therapy (RT) (1) and post-operative chemoradiation (2) have been used for esophageal cancer patients deemed high risk for recurrence after esophagectomy.
Defining opitmal RT target volume after esophagectomy is difficult due to significant changes in patient anatomy and function.
Some radiationon cologists advocated the inclusion of the anastomotic site within the irradiation volume due to concerns for potential increased relapse risk, while others did not subscribe to this practice due to concerns for increased treatment related toxicity.
We have previously reported patient outcome benefit using extended volume RT In management with high risk esophageal cancer patients underwent esopagectomy(3).
We have performed a Phase I study to evaluate the safety of subscription to this practice.
(1). Folk et al, Surgery, 113:1993
(2). Bedard et al, Cancer, 91;2001
(3). Yu et al, Radiother & Oncol, 73;200
Functional lung avoidance for individualized radiotherapy (FLAIR): Study protocol for a randomized, double-blind clinical trial.
BACKGROUND: Although radiotherapy is a key component of curative-intent treatment for locally advanced, unresectable non-small cell lung cancer (NSCLC), it can be associated with substantial pulmonary toxicity in some patients. Current radiotherapy planning techniques aim to minimize the radiation dose to the lungs, without accounting for regional variations in lung function. Many patients, particularly smokers, can have substantial regional differences in pulmonary ventilation patterns, and it has been hypothesized that preferential avoidance of functional lung during radiotherapy may reduce toxicity. Although several investigators have shown that functional lung can be identified using advanced imaging techniques and/or demonstrated the feasibility and theoretical advantages of avoiding functional lung during radiotherapy, to our knowledge this premise has never been tested via a prospective randomized clinical trial.
METHODS/DESIGN: Eligible patients will have Stage III NSCLC with intent to receive concurrent chemoradiotherapy (CRT). Every patient will undergo a pre-treatment functional lung imaging study using hyperpolarized 3He MRI in order to identify the spatial distribution of normally-ventilated lung. Before randomization, two clinically-approved radiotherapy plans will be devised for all patients on trial, termed standard and avoidance. The standard plan will be designed without reference to the functional state of the lung, while the avoidance plan will be optimized such that dose to functional lung is as low as reasonably achievable. Patients will then be randomized in a 1:1 ratio to receive either the standard or the avoidance plan, with both the physician and the patient blinded to the randomization results. This study aims to accrue a total of 64 patients within two years. The primary endpoint will be a pulmonary quality of life (QOL) assessment at 3 months post-treatment, measured using the functional assessment of cancer therapy-lung cancer subscale. Secondary endpoints include: pulmonary QOL at other time-points, provider-reported toxicity, overall survival, progression-free survival, and quality-adjusted survival.
DISCUSSION: This randomized, double-blind trial will comprehensively assess the impact of functional lung avoidance on pulmonary toxicity and quality of life in patients receiving concurrent CRT for locally advanced NSCLC.
TRIAL REGISTRATION: Clinicaltrials.gov identifier: NCT02002052
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Sources and characteristics of summertime organic aerosol in the Colorado Front Range: perspective from measurements and WRF-Chem modeling
Abstract. The evolution of organic aerosols (OAs) and their precursors in the boundary layer (BL) of the Colorado Front Range during the Front Range Air Pollution and Photochemistry Éxperiment (FRAPPÉ, July–August 2014) was analyzed by in situ measurements and chemical transport modeling. Measurements indicated significant production of secondary OA (SOA), with enhancement ratio of OA with respect to carbon monoxide (CO) reaching 0.085±0.003 µg m−3 ppbv−1. At background mixing ratios of CO, up to  ∼  1.8 µg m−3 background OA was observed, suggesting significant non-combustion contribution to OA in the Front Range. The mean concentration of OA in plumes with a high influence of oil and natural gas (O&G) emissions was  ∼  40 % higher than in urban-influenced plumes. Positive matrix factorization (PMF) confirmed a dominant contribution of secondary, oxygenated OA (OOA) in the boundary layer instead of fresh, hydrocarbon-like OA (HOA). Combinations of primary OA (POA) volatility assumptions, aging of semi-volatile species, and different emission estimates from the O&G sector were used in the Weather Research and Forecasting model coupled with Chemistry (WRF-Chem) simulation scenarios. The assumption of semi-volatile POA resulted in greater than a factor of 10 lower POA concentrations compared to PMF-resolved HOA. Including top-down modified O&G emissions resulted in substantially better agreements in modeled ethane, toluene, hydroxyl radical, and ozone compared to measurements in the high-O&G-influenced plumes. By including emissions from the O&G sector using the top-down approach, it was estimated that the O&G sector contributed to  <  5 % of total OA, but up to 38 % of anthropogenic SOA (aSOA) in the region. The best agreement between the measured and simulated median OA was achieved by limiting the extent of biogenic hydrocarbon aging and consequently biogenic SOA (bSOA) production. Despite a lower production of bSOA in this scenario, contribution of bSOA to total SOA remained high at 40–54 %. Future studies aiming at a better emissions characterization of POA and intermediate-volatility organic compounds (IVOCs) from the O&G sector are valuable
Extended vs. Small Field Irradiation in High Risk Post Esophagectomy Patients Receiving Combined Chemoradiation Therapy: A Decade Experience in Treatment of Esophageal Cancer
OBJECTIVE: To assess the impact of extended field irradiation with anastomotic coverage on local recurrence in high risk resected esophageal cancerpatients.
METHODS: From 1989-1999, high risk resected esophageal cancer cases receiving post-resection chemoradiation were reviewed. Adjuvant chemotherapy consisted of four cycles of fluorouracil-based regimens. Loco-regional irradiation with or without coverage of anastomotic site had radiation a dose range from 45-60 Gyat 1.8-2.0 Gy/fraction given with initial anterior-posterior/posterior-anterior arrangement with either extended (with anastomotic coverage), or small (without anastomotic coverage) field followed by oblique fields for boost.
RESULTS: One hundred eighty-eight charts were reviewed. Seventy-two patients were eligible for post-resection chemoradiation. Three patients had disease progression prior to therapy, and 69 patients were analyzed. The median age was 60 years (range 35-82 years) with 94% T2-3N1 and 65% were adenocarcinoma. As of January 2005 median followup was 30.5 months (range 3-142 months), the two-and five-year overall survival rates were 50% and 31%, respectively. First relapse rate after adjuvant therapy was 71% (n=49) and median time to relapse was about 30 months. Loco-regional relapse with small field was 25/35 (71.4%) and 2/14 (14.2%) with extended field (P\u3c0.001). Recurrence locally to anastomosis or adjacent site was 10/35 (28.6%) with small field and 0/14 (0%) with extended field (P=0.04).
CONCLUSION: At a minimum of 5-year followup, there is significant decrease in loco-regional relapse with the use of extended field in high risk resected esophageal cancer patients. This important improvement trend deserves further exploration in prospective randomized clinical trials
Erratum: CYP3A4 and seasonal variation in vitamin D status in addition to CYP2D6 contribute to therapeutic endoxifen level during tamoxifen therapy (Breast Cancer Research and Treatment (2013) 139 (95-105) DOI 10.1007/s10549-013-2511-4)
Relationship between bacterial strain type, host biomarkers, and mortality in clostridium difficile infection
Background: Despite substantial interest in biomarkers, their impact on clinical outcomes and variation with bacterial strain has rarely been explored using integrated databases. Methods: From September 2006 to May 2011, strains isolated from Clostridium difficile toxin enzyme immunoassay (EIA)-positive fecal samples from Oxfordshire, United Kingdom (approximately 600 000 people) underwent multilocus sequence typing. Fourteen-day mortality and levels of 15 baseline biomarkers were compared between consecutive C. difficile infections (CDIs) from different clades/sequence types (STs) and EIA-negative controls using Cox and normal regression adjusted for demographic/clinical factors. Results: Fourteen-day mortality was 13% in 2222 adults with 2745 EIA-positive samples (median, 78 years) vs 5% in 20 722 adults with 27 550 EIA-negative samples (median, 74 years) (absolute attributable mortality, 7.7%; 95% CI, 6.4%-9.0%). Mortality was highest in clade 5 CDIs (25% [16 of 63]; polymerase chain reaction (PCR) ribotype 078/ST 11), then clade 2 (20% [111 of 560]; 99% PCR ribotype 027/ST 1) versus clade 1 (12% [137 of 1168]; adjusted P <. 0001). Within clade 1, 14-day mortality was only 4% (3 of 84) in ST 44 (PCR ribotype 015) (adjusted P =. 05 vs other clade 1). Mean baseline neutrophil counts also varied significantly by genotype: 12.4, 11.6, and 9.5 × 109 neutrophils/L for clades 5, 2 and 1, respectively, vs 7.0 × 109 neutrophils/L in EIA-negative controls (P <. 0001) and 7.9 × 109 neutrophils/L in ST 44 (P =. 08). There were strong associations between C. difficile-type-specific effects on mortality and neutrophil/white cell counts (rho = 0.48), C-reactive-protein (rho = 0.43), eosinophil counts (rho =-0.45), and serum albumin (rho =-0.47). Biomarkers predicted 30%-40% of clade-specific mortality differences. Conclusions: C. difficile genotype predicts mortality, and excess mortality correlates with genotype-specific changes in biomarkers, strongly implicating inflammatory pathways as a major influence on poor outcome after CDI. PCR ribotype 078/ST 11 (clade 5) leads to severe CDI; thus ongoing surveillance remains essential
Major genetic discontinuity and novel toxigenic species in Clostridioides difficile taxonomy
Clostridioides difficile infection (CDI) remains an urgent global One Health threat. The genetic heterogeneity seen across C. difficile underscores its wide ecological versatility and has driven the significant changes in CDI epidemiology seen in the last 20 years. We analysed an international collection of over 12,000 C. difficile genomes spanning the eight currently defined phylogenetic clades. Through whole-genome average nucleotide identity, and pangenomic and Bayesian analyses, we identified major taxonomic incoherence with clear species boundaries for each of the recently described cryptic clades CI-III. The emergence of these three novel genomospecies predates clades C1-5 by millions of years, rewriting the global population structure of C. difficile specifically and taxonomy of the Peptostreptococcaceae in general. These genomospecies all show unique and highly divergent toxin gene architecture, advancing our understanding of the evolution of C. difficile and close relatives. Beyond the taxonomic ramifications, this work may impact the diagnosis of CDI
Life-history trait variation in a queen-size dimorphic ant
1. Size polymorphism is often connected to alternative life-history traits, which may eventually lead to distinct size classes. In the ant Myrmica ruginodis, larger macrogyne and smaller microgyne queen morphs have been suggested to follow different reproductive strategies, which has presumably resulted in several differences in their key life-history traits. 2. In this study, we examine the association of queen-size morphs with colony queen number (monogyny vs. polygyny), dispersal and queen recruitment patterns, as well as habitat associations of the queen morphs. We do this by sampling established queens from a large number of excavated nests from several populations, estimating genetic relatedness among coexisting queens and pitfall trapping free-ranging wingless queens. 3. Our results show that associations of queen morphs with colony queen number and nest-founding strategy holds only partly. The morph frequencies vary widely across populations from practically pure macrogyne to more than 50% microgyne, but the expected association of macrogyne occurrence with monogyny and microgyne with polygyny is not universal. Dispersal and queen recruitment patterns also show that although most macrogynes participate in nuptial flights and most microgynes are recruited back to their natal nests, a fraction of both morphs use the alternative strategy. 4. The polygynous microgyne morph has been suggested to specialize in stable habitats, but our results from Finnish mesic heath forests do not support this. This study shows that factors other than just queen size also influence life-history trait variation and reproductive strategies in ants.Peer reviewe
The Role of Gemcitabine in the Treatment of Cholangiocarcinoma and Gallbladder Cancer: A Systematic Review
BACKGROUND: Cholangiocarcinoma and gallbladder cancer are difficult to treat curatively. The treatment of choice is surgery, dependent on detection at a resectable stage. No chemotherapy or radiotherapy options have shown substantial activity. Gemcitabine has demonstrated response in similar cancers. Considering the lack of treatment options for cholangiocarcinoma and gallbladder cancer, a systematic review of the evidence on gemcitabine use for these indications was performed