133 research outputs found

    Cascade Joule-Thomson refrigerators

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    The design criteria for cascade Joule-Thomson refrigerators for cooling in the temperature range from 300 K to 4.2 K were studied. The systems considered use three or four refrigeration stages with various working gases to achieve the low temperatures. Each stage results in cooling to a progressively lower temperature and provides cooling at intermediate temperatures to remove the substantial amount of parasitic heat load encountered in a typical dewar. With careful dewar design considerable cooling can be achieved with moderate gas flows. For many applications, e.g., in the cooling of sensitive sensors, the fact that the refrigerator contains no moving parts and may be remotely located from the gas source is of considerable advantage. A small compressor suitable for providing the gas flows required was constructed

    The clinical cell-cycle risk (CCR) score is associated with metastasis after radiation therapy and provides guidance on when to forgo combined androgen deprivation therapy with dose-escalated radiation

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    PURPOSE: The clinical cell-cycle risk (CCR) score, which combines the University of California, San Francisco\u27s Cancer of the Prostate Risk Assessment (CAPRA) and the cell cycle progression (CCP) molecular score, has been validated to be prognostic of disease progression for men with prostate cancer. This study evaluated the ability of the CCR score to prognosticate the risk of metastasis in men receiving dose-escalated radiation therapy (RT) with or without androgen deprivation therapy (ADT). METHODS AND MATERIALS: This retrospective, multi-institutional cohort study included men with localized National Comprehensive Cancer Network (NCCN) intermediate-, high-, and very high-risk prostate cancer (N = 741). Patients were treated with dose-escalated RT with or without ADT. The primary outcome was time to metastasis. RESULTS: The CCR score prognosticated metastasis with a hazard ratio (HR) per unit score of 2.22 (95% confidence interval [CI], 1.71-2.89; P \u3c .001). The CCR score better prognosticated metastasis than NCCN risk group (CCR, P \u3c .001; NCCN, P = .46), CAPRA score (CCR, P = .002; CAPRA, P = .59), or CCP score (CCR, P \u3c .001; CCP, P = .59) alone. In bivariable analyses, CCR score remained highly prognostic when accounting for ADT versus no ADT (HR, 2.18; 95% CI, 1.61-2.96; P \u3c .001), ADT duration as a continuous variable (HR, 2.11; 95% CI, 1.59-2.79; P \u3c .001), or ADT given at or below the recommended duration for each NCCN risk group (HR, 2.19; 95% CI, 1.69-2.86; P \u3c .001). Men with CCR scores below or above the multimodality threshold (CCR score, 2.112) had a 10-year risk of metastasis of 3.7% and 21.24%, respectively. Men with below-threshold scores receiving RT alone had a 10-year risk of metastasis of 3.7%, and for men receiving RT plus ADT, the 10-year risk of metastasis was also 3.7%. CONCLUSIONS: The CCR score accurately and precisely prognosticates metastasis and adds clinically actionable information relative to guideline-recommended therapies based on NCCN risk in men undergoing dose-escalated RT with or without ADT. For men with scores below the multimodality threshold, adding ADT may not significantly reduce their 10-year risk of metastasis

    Inhibition of fatty acid oxidation as a therapy for MYC-overexpressing triple-negative breast cancer.

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    Expression of the oncogenic transcription factor MYC is disproportionately elevated in triple-negative breast cancer (TNBC), as compared to estrogen receptor-, progesterone receptor- or human epidermal growth factor 2 receptor-positive (RP) breast cancer. We and others have shown that MYC alters metabolism during tumorigenesis. However, the role of MYC in TNBC metabolism remains mostly unexplored. We hypothesized that MYC-dependent metabolic dysregulation is essential for the growth of MYC-overexpressing TNBC cells and may identify new therapeutic targets for this clinically challenging subset of breast cancer. Using a targeted metabolomics approach, we identified fatty acid oxidation (FAO) intermediates as being dramatically upregulated in a MYC-driven model of TNBC. We also identified a lipid metabolism gene signature in patients with TNBC that were identified from The Cancer Genome Atlas database and from multiple other clinical data sets, implicating FAO as a dysregulated pathway that is critical for TNBC cell metabolism. We found that pharmacologic inhibition of FAO catastrophically decreased energy metabolism in MYC-overexpressing TNBC cells and blocked tumor growth in a MYC-driven transgenic TNBC model and in a MYC-overexpressing TNBC patient-derived xenograft. These findings demonstrate that MYC-overexpressing TNBC shows an increased bioenergetic reliance on FAO and identify the inhibition of FAO as a potential therapeutic strategy for this subset of breast cancer

    Identification of men with low-risk biopsy-confirmed prostate cancer as candidates for active surveillance.

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    BACKGROUND: A combined clinical cell-cycle risk (CCR) score that incorporates prognostic molecular and clinical information has been recently developed and validated to improve prostate cancer mortality (PCM) risk stratification over clinical features alone. As clinical features are currently used to select men for active surveillance (AS), we developed and validated a CCR score threshold to improve the identification of men with low-risk disease who are appropriate for AS. METHODS: The score threshold was selected based on the 90th percentile of CCR scores among men who might typically be considered for AS based on NCCN low/favorable-intermediate risk criteria (CCR = 0.8). The threshold was validated using 10-year PCM in an unselected, conservatively managed cohort and in the subset of the same cohort after excluding men with high-risk features. The clinical effect was evaluated in a contemporary clinical cohort. RESULTS: In the unselected validation cohort, men with CCR scores below the threshold had a predicted mean 10-year PCM of 2.7%, and the threshold significantly dichotomized low- and high-risk disease (P = 1.2 × 10-5). After excluding high-risk men from the validation cohort, men with CCR scores below the threshold had a predicted mean 10-year PCM of 2.3%, and the threshold significantly dichotomized low- and high-risk disease (P = 0.020). There were no prostate cancer-specific deaths in men with CCR scores below the threshold in either analysis. The proportion of men in the clinical testing cohort identified as candidates for AS was substantially higher using the threshold (68.8%) compared to clinicopathologic features alone (42.6%), while mean 10-year predicted PCM risks remained essentially identical (1.9% vs. 2.0%, respectively). CONCLUSIONS: The CCR score threshold appropriately dichotomized patients into low- and high-risk groups for 10-year PCM, and may enable more appropriate selection of patients for AS

    Trends in non-metastatic prostate cancer management in the Northern and Yorkshire region of England, 2000–2006

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    Background: Our objective was to analyse variation in non-metastatic prostate cancer management in the Northern and Yorkshire region of England. Methods: We included 21 334 men aged ⩾55, diagnosed between 2000 and 2006. Principal treatment received was categorised into radical prostatectomy (11%), brachytherapy (2%), external beam radiotherapy (16%), hormone therapy (42%) and no treatment (29%). Results: The odds ratio (OR) for receiving a radical prostatectomy was 1.53 in 2006 compared with 2000 (95% CI 1.26–1.86), whereas the OR for receiving hormone therapy was 0.57 (0.51–0.64). Age was strongly associated with treatment received; radical treatments were significantly less likely in men aged ⩾75 compared with men aged 55–64 years, whereas the odds of receiving hormone therapy or no treatment were significantly higher in the older age group. The OR for receiving radical prostatectomy, brachytherapy or external beam radiotherapy were all significantly lower in the most deprived areas when compared with the most affluent (0.64 (0.55–0.75), 0.32 (0.22–0.47) and 0.83 (0.74–0.94), respectively) whereas the OR for receiving hormone therapy was 1.56 (1.42–1.71). Conclusions: This study highlights the variation and inequalities that exist in the management of non-metastatic prostate cancer in the Northern and Yorkshire region of England

    Reciprocal Interaction of Wnt and RXR-alpha Pathways in Hepatocyte Development and Hepatocellular Carcinoma

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    Genomic analysis of human hepatocellular carcinoma (HCC) is potentially confounded by the differentiation state of the hepatic cell-of-origin. Here we integrated genomic analysis of mouse HCC (with defined cell-of-origin) along with normal development. We found a major shift in expression of Wnt and RXR-alpha pathway genes (up and down, respectively) coincident with the transition from hepatoblasts to hepatocytes. A combined Wnt and RXR-alpha gene signature categorized HCCs into two subtypes (high Wnt, low RXR-alpha and low Wnt, high RXR-alpha), which matched cell-of-origin in mouse models and the differentiation state of human HCC. Suppression of RXR-alpha levels in hepatocytes increased Wnt signaling and enhanced tumorigenicity, whereas ligand activation of RXR-alpha achieved the opposite. These results corroborate that there are two main HCC subtypes that correspond to the degree of hepatocyte differentation and that RXR-alpha, in part via Wnt signaling, plays a key functional role in the hepatocyte-like subtype and potentially could serve as a selective therapeutic target

    Radiation-induced cancer after radiotherapy for non-Hodgkin's lymphoma of the head and neck: a retrospective study

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    <p>Abstract</p> <p>Background</p> <p>survivors of non-Hodgkin's lymphoma (NHL) are well known to be at an increased risk of second malignancies. In this study, we evaluated the incidence and clinical features of head and neck cancer (HNC) occurring after radiotherapy (RT) for NHL.</p> <p>Materials and methods</p> <p>We investigated the clinical records of 322 patients who had received RT for early-stage NHL of the head and neck at our institute between 1952 and 2000.</p> <p>Results</p> <p>There were 4 patients with a second HNC developing in the irradiated field, consisting of 2 patients with gum cancer, 1 case with tongue cancer and 1 case with maxillary sinus cancer. The pathological diagnosis in all the 4 patients was squamous cell carcinoma (SCC). Two of the patients (one with gum cancer and one with maxillary sinus cancer) died of the second HNC, while the remaining 2 patients are still living at the time of writing after therapy for the second HNC, with neither recurrence of the second tumor nor relapse of the primary tumor. The ratio of the observed to the expected number (O/E ratio) of a second HNC was calculated to be 12.7 (95%CI, 4.07–35.0), and the absolute excess risk (AER) per 10,000 person-years was 13.3. The median interval between the RT and the diagnosis of the second HNC was 17.0 years (range, 8.7 to 22.7 years).</p> <p>Conlusion</p> <p>The risk of HNC significantly increased after RT for early-stage NHL. These results suggest that second HNC can be regarded as one of the late complications of RT for NHL of the head and neck.</p

    Radical Prostatectomy Versus Radiation and Androgen Deprivation Therapy for Clinically Localized Prostate Cancer: How Good Is the Evidence?

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    PurposeThe optimal treatment of clinically localized prostate cancer is controversial. Most studies focus on biochemical (PSA) failure when comparing radical prostatectomy (RP) with radiation therapy (RT), but this endpoint has not been validated as predictive of overall survival (OS) or cause-specific survival (CSS). We analyzed the available literature to determine whether reliable conclusions could be made concerning the effectiveness of RP compared with RT with or without androgen deprivation therapy (ADT), assuming current treatment standards.MethodsArticles published between February 29, 2004, and March 1, 2015, that compared OS and CSS after RP or RT with or without ADT were included. Because the GRADE (Grading of Recommendations, Assessment, Development, and Evaluation) system emphasis is on randomized controlled clinical trials, a reliability score (RS) was explored to further understand the issues associated with the study quality of observational studies, including appropriateness of treatment, source of data, clinical characteristics, and comorbidity. Lower RS values indicated lower reliability.ResultsFourteen studies were identified, and 13 were completely evaluable. Thirteen of the 14 studies (93%) were observational studies with low-quality evidence. The median RS was 12 (range, 5-18); the median difference in 10-year OS and CSS favored RP over RT: 10% and 4%, respectively. In studies with a RS ≤12 (average RS 9) the 10-year OS and CSS median differences were 17% and 6%, respectively. For studies with a RS &gt;12 (average RS 15.5), the 10-year OS and CSS median differences were 5.5% and 1%, respectively. Thus, we observed an association between low RS and a higher percentage difference in OS and CSS.ConclusionsReliable evidence that RP provides a superior CSS to RT with ADT is lacking. The most reliable studies suggest that the differences in 10-year CSS between RP and RT are small, possibly &lt;1%

    Urinary Diversion for Severe Urinary Adverse Events of Prostate Radiation: Results from a Multi-Institutional Study

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    PurposeWe evaluated the short and long-term surgical outcomes of urinary diversion done for urinary adverse events arising from prostate radiation therapy. We hypothesized that patient characteristics are associated with complications after urinary diversion.Materials and methodsWe performed a retrospective cohort study of 100 men who underwent urinary diversion (urinary conduit or continent catheterizable pouch) due to urinary adverse events after prostate radiotherapy from 2007 to 2016 from 9 academic centers in the United States. Outcome measurements included predictors of short and long-term complications, and readmission after urinary diversion of patients who had prostate cancer treated with radiotherapy. The data were summarized using descriptive statistics and univariate associations with complications were identified with logistic regression controlling for center.ResultsMean patient age was 71 years and median time from radiotherapy to urinary diversion was 8 years. Overall 81 (81%) patients had combined modality therapy (radical prostatectomy plus radiotherapy or various combinations of radiotherapy). Grade 3a or greater Clavien-Dindo complications occurred in 31 (35%) men, including 4 deaths (4.5%). Normal weight men had more short-term complications compared to overweight (OR 4.9, 95% CI 1.3-23.1, p=0.02) and obese men (OR 6.3, 95% CI 1.6-31.1, p=0.009). Hospital readmission within 6 weeks of surgery occurred for 35 (38%) men. Surgery was needed to treat long-term complications after urinary diversion in 19 (22%) patients with a median followup of 16.3 months.ConclusionsUrinary diversion after prostate radiotherapy has a considerable short and long-term surgical complication rate. Urinary diversion most often cannot be avoided in these patients but appreciation of the risks allows for informed shared decision making between surgeons and patients
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