215 research outputs found
Temperature dependence of the spin and orbital magnetization density in around the spin-orbital compensation point
Non-resonant ferromagnetic x-ray diffraction has been used to separate the
spin and orbital contribution to the magnetization density of the proposed
zero-moment ferromagnet . The alignment of the
spin and orbital moments relative to the net magnetization shows a sign
reversal at 84K, the compensation temperature. Below this temperature the
orbital moment is larger than the spin moment, and vice versa above it. This
result implies that the compensation mechanism is driven by the different
temperature dependencies of the spin and orbital moments. Specific heat
data indicate that the system remains ferromagnetically ordered throughout
Photoionization of ultracold and Bose-Einstein condensed Rb atoms
Photoionization of a cold atomic sample offers intriguing possibilities to
observe collective effects at extremely low temperatures. Irradiation of a
rubidium condensate and of cold rubidium atoms within a magneto-optical trap
with laser pulses ionizing through 1-photon and 2-photon absorption processes
has been performed. Losses and modifications in the density profile of the
remaining trapped cold cloud or the remaining condensate sample have been
examined as function of the ionizing laser parameters. Ionization
cross-sections were measured for atoms in a MOT, while in magnetic traps losses
larger than those expected for ionization process were measured.Comment: 9 pages, 7 figure
Development of an algorithm to identify small cell lung cancer patients in claims databases
IntroductionThe treatment landscape of small cell lung cancer (SCLC) is evolving. Evidence generated from administrative claims is needed to characterize real-world SCLC patients. However, the current ICD-10 coding system cannot distinguish SCLC from non-small cell lung cancer (NSCLC). We developed and estimated the accuracy of an algorithm to identify SCLC in claims-only databases.MethodsWe performed a cross-sectional study of lung cancer patients diagnosed from 2016-2017 using the Surveillance, Epidemiology and End Results (SEER), linked with Medicare database. The analysis included two phases – data exploration (utilizing a 25% random sample) and data validation (remaining 75% sample). The SEER definition of SCLC and NSCLC were used as the gold standard. Claims-based algorithms were identified and evaluated for their sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV).ResultsThe eligible cohort included 31,912 lung cancer patients. The mean age was 76.3 years, 44.6% were male, with 9.4% having SCLC and 90.6% identified as NSCLC using SEER. The exploration analysis identified potential algorithms based on treatment data. In the validation analysis of 7,438 lung cancer patients who received systemic treatment in the outpatient setting, an etoposide-based algorithm (etoposide use in 180 days following lung cancer diagnosis) to identify SCLC showed: sensitivity 95%, specificity 95%, PPV 82% and NPV 99%.DiscussionAn etoposide treatment-based algorithm showed good accuracy in identifying SCLC patients. Such algorithms can facilitate analyses of treatment patterns, outcomes, healthcare resource and costs among treated SCLC patients, thereby bolstering the evidence-base for best patient care
Long-term follow-up in patients with coeliac disease in the pandemic-era: A view from Sheffield the NHS England national centre for adult coeliac disease
Aim: To explore patients’ follow-up preferences. Background: Optimal follow-up strategies for patients with coeliac disease remain a subject of debate. Research suggests patients’ prefer review by dietitians with a doctor available as required. Methods: Patients with coeliac disease under review at our centre, completed a questionnaire assessing their views on what makes follow-up useful based on specific criteria. Bloods tests, symptoms review, dietary assessment, opportunity to ask questions and reassurance. Patients’ preferences between follow-up with a hospital doctor, a hospital dietitian, a hospital dietitian with a doctor available, a general practitioner, no follow-up or access when needed were also evaluated. Results: 138 adult patients completed the questionnaire, 80% of patients reported following a strict gluten free diet (mean diagnosis was 7.2 years). Overall, 60% found their follow-up to be ‘very useful’ valuing their review of blood tests and symptoms (71%) reassurance (60%) and opportunity to ask questions (58%). Follow-up by a dietitian with a doctor available was the most preferred option of review (p<0.001) except when compared to hospital doctor (p=0.75). Novel modalities of follow-up such as telephone and video reviews were regarded as of equal value to face-to-face appointments (65% and 62% respectively). Digital applications were significantly less preferable (38%, p<0.001). Conclusion: Follow-up by a dietitian with a doctor available as needed was the most preferred follow-up method. However, in this study follow-up by a dietitian with doctor available and hospital doctor alone was statistically equivalent. Many patients consider telephone and video follow-up of equal value to face-to-face reviews
Breast cancer risk in ataxia telangiectasia (AT) heterozygotes: haplotype study in French AT families
ATM variants 7271T>G and IVS10-6T>G among women with unilateral and bilateral breast cancer
Recent reports suggest that two ATM gene mutations, 7271T>G and IVS10-6T>G, are associated with a high risk of breast cancer among multiple-case families. To assess the importance of these two mutations in another 'high-risk' group, young women (under age 51) with multiple primaries, we screened a large population-based series of young women with bilateral breast cancer and compared the frequency of these mutations among similar women diagnosed with unilateral breast cancer. The 1149 women included were enrolled in an ongoing population-based case-control study of the genetic factors that contribute to bilateral breast cancer; they were not selected on the basis of family history of cancer. Screening for 7271T>G and IVS10-6T>G ATM gene mutations was conducted using DHPLC followed by direct sequencing. The 7271T>G mutation was detected in one out of 638 (0.2%) women with unilateral breast cancer and in none of the bilateral cases, and the IVS10-6T>G mutation in one out of 511 (0.2%) bilateral and in eight out of 638 (1.3%) unilateral breast cancer cases. Carriers of either mutation were not limited to women with a family history. Given the likelihood that young women with bilateral breast cancer have a genetic predisposition, the observed mutation distribution is contrary to that expected if these two mutations were to play an important role in breast carcinogenesis among individuals at high risk
Physical activity and diet behaviour in colorectal cancer patients receiving chemotherapy: associations with quality of life
Correlations of EGFR mutations and increases in EGFR and HER2 copy number to gefitinib response in a retrospective analysis of lung cancer patients
<p>Abstract</p> <p>Background</p> <p>Gefitinib, a small molecule tyrosine kinase inhibitor of the Epidermal Growth Factor Receptor (<it>EGFR</it>), has shown limited efficacy in the treatment of lung cancer. Recognized clinical predictors of response to this drug, specifically female, non-smoker, Asian descent, and adenocarcinoma, together suggest a genetic basis for drug response. Recent studies have addressed the relationship between response and either sequence mutations or increased copy number of specific receptor tyrosine kinases. We set out to examine the relationship between response and the molecular status of two such kinases, <it>EGFR </it>and <it>HER2</it>, in 39 patients treated with gefitinib at the BC Cancer Agency.</p> <p>Methods</p> <p>Archival patient material was reviewed by a pathologist and malignant cells were selectively isolated by laser microdissection or manual recovery of cells from microscope slides. Genomic DNA was extracted from 37 such patient samples and exons 18–24, coding for the tyrosine kinase domain of <it>EGFR</it>, were amplified by PCR and sequenced. <it>EGFR </it>and <it>HER2 </it>copy number status were also assessed using FISH in 26 samples. Correlations between molecular features and drug response were assessed using the two-sided Fisher's exact test.</p> <p>Results</p> <p>Mutations previously correlated with response were detected in five tumours, four with exon 19 deletions and one with an exon 21 missense L858R point mutation. Increased gene copy number was observed in thirteen tumours, seven with <it>EGFR </it>amplification, three with <it>HER2 </it>amplification, and three with amplification of both genes. In our study cohort, a correlation was not observed between response and <it>EGFR </it>mutations (exon 19 deletion p = 0.0889, we observed a single exon 21 mutation in a non-responder) or increases in <it>EGFR </it>or <it>HER2 </it>copy number (p = 0.552 and 0.437, respectively).</p> <p>Conclusion</p> <p>Neither mutation of <it>EGFR </it>nor increased copy number of <it>EGFR </it>or <it>HER2 </it>was diagnostic of response to gefitinib in this cohort. However, validation of these features in a larger sample set is appropriate. Identification of additional predictive biomarkers beyond <it>EGFR </it>status may be necessary to accurately predict treatment outcome.</p
Atypical hemolytic uremic syndrome in the era of terminal complement inhibition: an observational cohort study
Historically, the majority of patients with complement-mediated atypical hemolytic uremic syndrome (CaHUS) progress to end-stage kidney disease (ESKD). Single-arm trials of eculizumab with a short follow-up suggested efficacy. We prove, for the first time to our knowledge, in a genotype matched CaHUS cohort that the 5-year cumulative estimate of ESKD-free survival improved from 39.5% in a control cohort to 85.5% in the eculizumab-treated cohort (hazard ratio, 4.95; 95% confidence interval [CI], 2.75-8.90; P = .000; number needed to treat, 2.17 [95% CI, 1.81-2.73]). The outcome of eculizumab treatment is associated with the underlying genotype. Lower serum creatinine, lower platelet count, lower blood pressure, and younger age at presentation as well as shorter time between presentation and the first dose of eculizumab were associated with estimated glomerular filtration rate >60 ml/min at 6 months in multivariate analysis. The rate of meningococcal infection in the treated cohort was 550 times greater than the background rate in the general population. The relapse rate upon eculizumab withdrawal was 1 per 9.5 person years for patients with a pathogenic mutation and 1 per 10.8 person years for those with a variant of uncertain significance. No relapses were recorded in 67.3 person years off eculizumab in those with no rare genetic variants. Eculizumab was restarted in 6 individuals with functioning kidneys in whom it had been stopped, with no individual progressing to ESKD. We demonstrated that biallelic pathogenic mutations in RNA-processing genes, including EXOSC3, encoding an essential part of the RNA exosome, cause eculizumab nonresponsive aHUS. Recessive HSD11B2 mutations causing apparent mineralocorticoid excess may also present with thrombotic microangiopathy
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