| 1. |
- Beal, Jacob, et al.
(författare)
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Robust estimation of bacterial cell count from optical density
- 2020
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Ingår i: Communications Biology. - : Springer Science and Business Media LLC. - 2399-3642. ; 3:1
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Tidskriftsartikel (refereegranskat)abstract
- Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data.
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| 2. |
- De Marco, O., et al.
(författare)
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The messy death of a multiple star system and the resulting planetary nebula as observed by JWST
- 2022
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Ingår i: Nature Astronomy. - : Springer Science and Business Media LLC. - 2397-3366. ; 6:12, s. 1421-1432
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Tidskriftsartikel (refereegranskat)abstract
- Planetary nebulae—the ejected envelopes of red giant stars—provide us with a history of the last, mass-losing phases of 90% of stars initially more massive than the Sun. Here we analyse images of the planetary nebula NGC 3132 from the James Webb Space Telescope (JWST) Early Release Observations. A structured, extended hydrogen halo surrounding an ionized central bubble is imprinted with spiral structures, probably shaped by a low-mass companion orbiting the central star at about 40–60 au. The images also reveal a mid-infrared excess at the central star, interpreted as a dusty disk, which is indicative of an interaction with another closer companion. Including the previously known A-type visual companion, the progenitor of the NGC 3132 planetary nebula must have been at least a stellar quartet. The JWST images allow us to generate a model of the illumination, ionization and hydrodynamics of the molecular halo, demonstrating the power of JWST to investigate complex stellar outflows. Furthermore, new measurements of the A-type visual companion allow us to derive the value for the mass of the progenitor of a central star with excellent precision: 2.86 ± 0.06 M⊙. These results serve as pathfinders for future JWST observations of planetary nebulae, providing unique insight into fundamental astrophysical processes including colliding winds and binary star interactions, with implications for supernovae and gravitational-wave systems.
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| 3. |
- Ghaneh, Paula, et al.
(författare)
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The Impact of Positive Resection Margins on Survival and Recurrence Following Resection and Adjuvant Chemotherapy for Pancreatic Ductal Adenocarcinoma
- 2019
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Ingår i: Annals of Surgery. - 0003-4932 .- 1528-1140. ; 269:3, s. 520-529
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Tidskriftsartikel (refereegranskat)abstract
- Objective and Background: Local and distant disease recurrence are frequently observed following pancreatic cancer resection, but an improved understanding of resection margin assessment is required to aid tailored therapiesMethods: Analyses were carried out to assess the association between clinical characteristics and margin involvement as well as the effects of individual margin involvement on site of recurrence and overall and recurrence-free survival using individual patient data from the European Study Group for Pancreatic Cancer (ESPAC)-3 randomized controlled trial.Results: There were 1151 patients, of whom 505 (43.9%) had an RI resection. The median and 95% confidence interval (CI) overall survival was 24.9 (22.9-27.2) months for 646 (56.1%) patients with resection margin negative R0 >1 mm) tumors, 25.4 (21.6 30.4) months for 146 (12.7%) patients with RI <1 mm positive resection margins, and 18.7 (17.2-21.1) months for 359 (31.2%) patients with R1-direct positive margins (P < 0.001). In multivariable analysis, overall R 1-direct tumor margins, poor tumor differentiation, positive lymph node status, WHO performance status ≥ 1, maximum tumor size, and RI-direct posterior resection margin were all independently significantly associated with reduced overall and recurrence-free survival. Competing risks analysis showed that overall R1-direct positive resection margin status, positive lymph node status. WHO performance status 1, and R1-direct positive superior mesenteric/medial margin resection status were all significantly associated with local recurrence.Conclusions: RI-direct resections were associated with significantly reduced overall and recurrence-free survival following pancreatic cancer resection. Resection margin involvement was also associated with an increased risk for local recurrence.
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| 4. |
- Greenhalf, William, et al.
(författare)
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Pancreatic Cancer hENT1 Expression and Survival From Gemcitabine in Patients From the ESPAC-3 Trial
- 2014
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Ingår i: Journal of the National Cancer Institute. - : Oxford University Press (OUP). - 0027-8874 .- 1460-2105. ; 106:1, s. djt347-
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Tidskriftsartikel (refereegranskat)abstract
- Background Human equilibrative nucleoside transporter 1 (hENT1) levels in pancreatic adenocarcinoma may predict survival in patients who receive adjuvant gemcitabine after resection. Methods Microarrays from 434 patients randomized to chemotherapy in the ESPAC-3 trial (plus controls from ESPAC-1/3) were stained with the 10D7G2 anti-hENT1 antibody. Patients were classified as having high hENT1 expression if the mean H score for their cores was above the overall median H score (48). High and low hENT1-expressing groups were compared using Kaplan-Meier curves, log-rank tests, and Cox proportional hazards models. All statistical tests were two-sided. Results Three hundred eighty patients (87.6%) and 1808 cores were suitable and included in the final analysis. Median overall survival for gemcitabine-treated patients (n = 176) was 23.4 (95% confidence interval [CI] = 18.3 to 26.0) months vs 23.5 (95% CI = 19.8 to 27.3) months for 176 patients treated with 5-fluorouracil/folinic acid (months vs 23.5 (95% CI = 19.8 to 27.3) months for 176 patients treated with 5-fluorouracil/folinic acid (chi(2)(1)=0.24; P = .62). Median survival for patients treated with gemcitabine was 17.1 (95% CI = 14.3 to 23.8) months for those with low hENT1 expression vs 26.2 (95% CI = 21.2 to 31.4) months for those with high hENT1 expression (chi(2)(1)=9.87; P = .002). For the 5-fluorouracil group, median survival was 25.6 (95% CI = 20.1 to 27.9) and 21.9 (95% CI = 16.0 to 28.3) months for those with low and high hENT1 expression, respectively (chi(2)(1) = 0.83; P = .36). hENT1 levels were not predictive of survival for the 28 patients of the observation group (chi(2)(1) = 0.37; P = .54). Multivariable analysis confirmed hENT1 expression as a predictive marker in gemcitabine-treated (Wald chi(2)(1) = 9.16; P = .003) but not 5-fluorouracil-treated (Wald chi(2)(1) = 1.22; P = .27) patients. Conclusions Subject to prospective validation, gemcitabine should not be used for patients with low tumor hENT1 expression.
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| 5. |
- Jones, Robert P., et al.
(författare)
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Patterns of Recurrence After Resection of Pancreatic Ductal Adenocarcinoma : A Secondary Analysis of the ESPAC-4 Randomized Adjuvant Chemotherapy Trial
- 2019
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Ingår i: JAMA Surgery. - : AMER MEDICAL ASSOC. - 2168-6254 .- 2168-6262. ; 154:11, s. 1038-1048
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Tidskriftsartikel (refereegranskat)abstract
- Importance: The patterns of disease recurrence after resection of pancreatic ductal adenocarcinoma with adjuvant chemotherapy remain unclear.Objective: To define patterns of recurrence after adjuvant chemotherapy and the association with survival.Design, Setting, and Participants: Prospectively collected data from the phase 3 European Study Group for Pancreatic Cancer 4 adjuvant clinical trial, an international multicenter study. The study included 730 patients who had resection and adjuvant chemotherapy for pancreatic cancer. Data were analyzed between July 2017 and May 2019.Interventions: Randomization to adjuvant gemcitabine or gemcitabine plus capecitabine.Main Outcomes and Measures: Overall survival, recurrence, and sites of recurrence.Results: Of the 730 patients, median age was 65 years (range 37-81 years), 414 were men (57%), and 316 were women (43%). The median follow-up time from randomization was 43.2 months (95% CI, 39.7-45.5 months), with overall survival from time of surgery of 27.9 months (95% CI, 24.8-29.9 months) with gemcitabine and 30.2 months (95% CI, 25.8-33.5 months) with the combination (HR, 0.81; 95% CI, 0.68-0.98; P=.03). The 5-year survival estimates were 17.1% (95% CI, 11.6%-23.5%) and 28.0% (22.0%-34.3%), respectively. Recurrence occurred in 479 patients (65.6%); another 78 patients (10.7%) died without recurrence. Local recurrence occurred at a median of 11.63 months (95% CI, 10.05-12.19 months), significantly different from those with distant recurrence with a median of 9.49 months (95% CI, 8.44-10.71 months) (HR, 1.21; 95% CI, 1.01-1.45; P=.04). Following recurrence, the median survival was 9.36 months (95% CI, 8.08-10.48 months) for local recurrence and 8.94 months (95% CI, 7.82-11.17 months) with distant recurrence (HR, 0.89; 95% CI, 0.73-1.09; P=.27). The median overall survival of patients with distant-only recurrence (23.03 months; 95% CI, 19.55-25.85 months) or local with distant recurrence (23.82 months; 95% CI, 17.48-28.32 months) was not significantly different from those with only local recurrence (24.83 months; 95% CI, 22.96-27.63 months) (P=.85 and P=.35, respectively). Gemcitabine plus capecitabine had a 21% reduction of death following recurrence compared with monotherapy (HR, 0.79; 95% CI, 0.64-0.98; P=.03).Conclusions and Relevance: There were no significant differences between the time to recurrence and subsequent and overall survival between local and distant recurrence. Pancreatic cancer behaves as a systemic disease requiring effective systemic therapy after resection.Trial Registration: ClinicalTrials.gov identifier: NCT00058201, EudraCT 2007-004299-38, and ISRCTN 96397434. This secondary analysis of a randomized clinical trial investigates patterns of recurrence after adjuvant chemotherapy in pancreatic cancer and the association with survival.
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| 6. |
- Klionsky, Daniel J., et al.
(författare)
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Guidelines for the use and interpretation of assays for monitoring autophagy
- 2012
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Ingår i: Autophagy. - : Informa UK Limited. - 1554-8635 .- 1554-8627. ; 8:4, s. 445-544
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Forskningsöversikt (refereegranskat)abstract
- In 2008 we published the first set of guidelines for standardizing research in autophagy. Since then, research on this topic has continued to accelerate, and many new scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Accordingly, it is important to update these guidelines for monitoring autophagy in different organisms. Various reviews have described the range of assays that have been used for this purpose. Nevertheless, there continues to be confusion regarding acceptable methods to measure autophagy, especially in multicellular eukaryotes. A key point that needs to be emphasized is that there is a difference between measurements that monitor the numbers or volume of autophagic elements (e.g., autophagosomes or autolysosomes) at any stage of the autophagic process vs. those that measure flux through the autophagy pathway (i.e., the complete process); thus, a block in macroautophagy that results in autophagosome accumulation needs to be differentiated from stimuli that result in increased autophagic activity, defined as increased autophagy induction coupled with increased delivery to, and degradation within, lysosomes (in most higher eukaryotes and some protists such as Dictyostelium) or the vacuole (in plants and fungi). In other words, it is especially important that investigators new to the field understand that the appearance of more autophagosomes does not necessarily equate with more autophagy. In fact, in many cases, autophagosomes accumulate because of a block in trafficking to lysosomes without a concomitant change in autophagosome biogenesis, whereas an increase in autolysosomes may reflect a reduction in degradative activity. Here, we present a set of guidelines for the selection and interpretation of methods for use by investigators who aim to examine macroautophagy and related processes, as well as for reviewers who need to provide realistic and reasonable critiques of papers that are focused on these processes. These guidelines are not meant to be a formulaic set of rules, because the appropriate assays depend in part on the question being asked and the system being used. In addition, we emphasize that no individual assay is guaranteed to be the most appropriate one in every situation, and we strongly recommend the use of multiple assays to monitor autophagy. In these guidelines, we consider these various methods of assessing autophagy and what information can, or cannot, be obtained from them. Finally, by discussing the merits and limits of particular autophagy assays, we hope to encourage technical innovation in the field.
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| 7. |
- Lorenzen, Eline D., et al.
(författare)
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Species-specific responses of Late Quaternary megafauna to climate and humans
- 2011
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Ingår i: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 479:7373, s. 359-364
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Tidskriftsartikel (refereegranskat)abstract
- Despite decades of research, the roles of climate and humans in driving the dramatic extinctions of large-bodied mammals during the Late Quaternary period remain contentious. Here we use ancient DNA, species distribution models and the human fossil record to elucidate how climate and humans shaped the demographic history of woolly rhinoceros, woolly mammoth, wild horse, reindeer, bison and musk ox. We show that climate has been a major driver of population change over the past 50,000 years. However, each species responds differently to the effects of climatic shifts, habitat redistribution and human encroachment. Although climate change alone can explain the extinction of some species, such as Eurasian musk ox and woolly rhinoceros, a combination of climatic and anthropogenic effects appears to be responsible for the extinction of others, including Eurasian steppe bison and wild horse. We find no genetic signature or any distinctive range dynamics distinguishing extinct from surviving species, emphasizing the challenges associated with predicting future responses of extant mammals to climate and human-mediated habitat change.
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| 8. |
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| 9. |
- Mah, Jean K, et al.
(författare)
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A multinational study on motor function in early-onset FSHD.
- 2018
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Ingår i: Neurology. - 1526-632X. ; 90:15, s. e1333-e1338
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Tidskriftsartikel (refereegranskat)abstract
- To investigate motor function associations with age, sex, and D4Z4 repeats among participants with early-onset facioscapulohumeral muscular dystrophy (FSHD) type 1 as defined by weakness onset before 10 years of age.We collected standardized motor assessments, including manual muscle testing (MMT), quantitative muscle testing, functional motor evaluations, and clinical severity scores (CSSs), at 12 Cooperative International Neuromuscular Research Group centers. To measure associations, we used linear regression models adjusted for sex, evaluation age, age at onset of weakness, and D4Z4 repeats.Among 52 participants (60% female, mean age 22.9 ± 14.7 years), weakness was most pronounced in the shoulder and abdominal musculature. Older enrollment age was associated with greater CSSs (p = 0.003). When adjusted for enrollment age, sex, and D4Z4 repeats, younger age at onset of facial weakness was associated with greater CSSs, slower velocities in timed function tests, and lower MMT scores (p < 0.05).Significant clinical variability was observed in early-onset FSHD. Earlier age at onset of facial weakness was associated with greater disease severity. Longitudinal assessments are needed to determine the rate of disease progression in this population.
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| 10. |
- Neoptolemos, John P., et al.
(författare)
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Comparison of adjuvant gemcitabine and capecitabine with gemcitabine monotherapy in patients with resected pancreatic cancer (ESPAC-4) : a multicentre, open-label, randomised, phase 3 trial
- 2017
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Ingår i: The Lancet. - 0140-6736 .- 1474-547X. ; 389:10073, s. 1011-1024
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Tidskriftsartikel (refereegranskat)abstract
- Background: The ESPAC-3 trial showed that adjuvant gemcitabine is the standard of care based on similar survival to and less toxicity than adjuvant 5-fluorouracil/folinic acid in patients with resected pancreatic cancer. Other clinical trials have shown better survival and tumour response with gemcitabine and capecitabine than with gemcitabine alone in advanced or metastatic pancreatic cancer. We aimed to determine the efficacy and safety of gemcitabine and capecitabine compared with gemcitabine monotherapy for resected pancreatic cancer.Methods: We did a phase 3, two-group, open-label, multicentre, randomised clinical trial at 92 hospitals in England, Scotland, Wales, Germany, France, and Sweden. Eligible patients were aged 18 years or older and had undergone complete macroscopic resection for ductal adenocarcinoma of the pancreas (R0 or R1 resection). We randomly assigned patients (1: 1) within 12 weeks of surgery to receive six cycles of either 1000 mg/m(2) gemcitabine alone administered once a week for three of every 4 weeks (one cycle) or with 1660 mg/m(2) oral capecitabine administered for 21 days followed by 7 days' rest (one cycle). Randomisation was based on a minimisation routine, and country was used as a stratification factor. The primary endpoint was overall survival, measured as the time from randomisation until death from any cause, and assessed in the intention-to-treat population. Toxicity was analysed in all patients who received trial treatment. This trial was registered with the EudraCT, number 2007-004299-38, and ISRCTN, number ISRCTN96397434.Findings: Of 732 patients enrolled, 730 were included in the final analysis. Of these, 366 were randomly assigned to receive gemcitabine and 364 to gemcitabine plus capecitabine. The Independent Data and Safety Monitoring Committee requested reporting of the results after there were 458 (95%) of a target of 480 deaths. The median overall survival for patients in the gemcitabine plus capecitabine group was 28.0 months (95% CI 23.5-31.5) compared with 25.5 months (22.7-27.9) in the gemcitabine group (hazard ratio 0.82 [95% CI 0.68-0.98], p=0.032). 608 grade 3-4 adverse events were reported by 226 of 359 patients in the gemcitabine plus capecitabine group compared with 481 grade 3-4 adverse events in 196 of 366 patients in the gemcitabine group.Interpretation: The adjuvant combination of gemcitabine and capecitabine should be the new standard of care following resection for pancreatic ductal adenocarcinoma.
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