| 51. |
- Hwang, K-J, et al.
(författare)
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Magnetic Reconnection Inside a Flux Rope Induced by Kelvin-Helmholtz Vortices
- 2020
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Ingår i: Journal of Geophysical Research - Space Physics. - 2169-9380 .- 2169-9402. ; 125:4
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Tidskriftsartikel (refereegranskat)abstract
- On 5 May 2017, MMS observed a crater-type flux rope on the dawnside tailward magnetopause with fluctuations. The boundary-normal analysis shows that the fluctuations can be attributed to nonlinear Kelvin-Helmholtz (KH) waves. Reconnection signatures such as flow reversals and Joule dissipation were identified at the leading and trailing edges of the flux rope. In particular, strong northward electron jets observed at the trailing edge indicated midlatitude reconnection associated with the 3-D structure of the KH vortex. The scale size of the flux rope, together with reconnection signatures, strongly supports the interpretation that the flux rope was generated locally by KH vortex-induced reconnection. The center of the flux rope also displayed signatures of guide-field reconnection (out-of-plane electron jets, parallel electron heating, and Joule dissipation). These signatures indicate that an interface between two interlinked flux tubes was undergoing interaction, causing a local magnetic depression, resulting in an M-shaped crater flux rope, as supported by reconstruction.
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| 52. |
- Hwang, K. -J, et al.
(författare)
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Microscale Processes Determining Macroscale Evolution of Magnetic Flux Tubes along Earth's Magnetopause
- 2021
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Ingår i: Astrophysical Journal. - : Institute of Physics Publishing (IOPP). - 0004-637X .- 1538-4357. ; 914:1
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Tidskriftsartikel (refereegranskat)abstract
- An important process affecting solar wind-Earth's magnetosphere coupling is nonsteady dayside magnetic reconnection, observationally evidenced by a flux transfer event (FTE) that shows a bipolar variation of the magnetic field component normal to the magnetopause. FTEs often consist of two interlinked flux tubes, but, local kinetic processes between the flux tubes are not understood in the context of the FTE structuring, evolution, and impact. An FTE observed by the Magnetospheric Multiscale mission on 2017 December 18 consisted of two flux tubes of different topology. One includes field lines with ends connected to the northern and southern hemispheres while the other includes field lines with both ends connected to the magnetosheath. Reconnection occurring at the flux-tube interface indicates how interacting flux tubes evolve into a flux rope with helical magnetic topology that is either closed or open. This study demonstrates a new aspect of how micro- to meso-scale dynamics occurring within FTEs determines their macroscale characteristics and evolution.
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| 53. |
- Jayasekara, Harindra, et al.
(författare)
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Lifetime alcohol intake, drinking patterns over time and risk of stomach cancer : A pooled analysis of data from two prospective cohort studies
- 2021
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Ingår i: International Journal of Cancer. - : Wiley. - 0020-7136 .- 1097-0215. ; 148:11, s. 2759-2773
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Tidskriftsartikel (refereegranskat)abstract
- Alcohol consumption is causally linked to several cancers but the evidence for stomach cancer is inconclusive. In our study, the association between long-term alcohol intake and risk of stomach cancer and its subtypes was evaluated. We performed a pooled analysis of data collected at baseline from 491 714 participants in the European Prospective Investigation into Cancer and Nutrition and the Melbourne Collaborative Cohort Study. Hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated for incident stomach cancer in relation to lifetime alcohol intake and group-based life course intake trajectories, adjusted for potential confounders including Helicobacter pylori infection. In all, 1225 incident stomach cancers (78% noncardia) were diagnosed over 7 094 637 person-years; 984 in 382 957 study participants with lifetime alcohol intake data (5 455 507 person-years). Although lifetime alcohol intake was not associated with overall stomach cancer risk, we observed a weak positive association with noncardia cancer (HR = 1.03, 95% CI: 1.00-1.06 per 10 g/d increment), with a HR of 1.50 (95% CI: 1.08-2.09) for ≥60 g/d compared to 0.1 to 4.9 g/d. A weak inverse association with cardia cancer (HR = 0.93, 95% CI: 0.87-1.00) was also observed. HRs of 1.48 (95% CI: 1.10-1.99) for noncardia and 0.51 (95% CI: 0.26-1.03) for cardia cancer were observed for a life course trajectory characterized by heavy decreasing intake compared to light stable intake (Phomogeneity =.02). These associations did not differ appreciably by smoking or H pylori infection status. Limiting alcohol use during lifetime, particularly avoiding heavy use during early adulthood, might help prevent noncardia stomach cancer. Heterogeneous associations observed for cardia and noncardia cancers may indicate etiologic differences.
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| 54. |
- Jayasekara, Harindra, et al.
(författare)
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Prediagnosis alcohol intake and metachronous cancer risk in cancer survivors : A prospective cohort study
- 2021
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Ingår i: International Journal of Cancer. - : Wiley. - 0020-7136 .- 1097-0215. ; 149:4, s. 827-838
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Tidskriftsartikel (refereegranskat)abstract
- Alcohol consumption is a known cause of cancer, but its role in the etiology of second primary (metachronous) cancer is uncertain. Associations between alcohol intake up until study enrollment (prediagnosis) and risk of metachronous cancer were estimated using 9435 participants in the Melbourne Collaborative Cohort Study who were diagnosed with their first invasive cancer after enrollment (1990-1994). Follow-up was from date of first invasive cancer until diagnosis of metachronous cancer, death or censor date (February 2018), whichever came first. Alcohol intake for 10-year periods from age 20 until decade encompassing baseline using recalled beverage-specific frequency and quantity was used to calculate baseline and lifetime intakes, and group-based intake trajectories. We estimated hazard ratios (HRs) and 95% confidence intervals (CIs), adjusted for potential confounders. After a mean follow-up of 7 years, 1512 metachronous cancers were identified. A 10 g/d increment in prediagnosis lifetime alcohol intake (HR = 1.03, 95% CI = 1.00-1.06; Pvalue = .02) and an intake of ≥60 g/d (HR = 1.32, 95% CI = 1.01-1.73) were associated with increased metachronous cancer risk. We observed positive associations (per 10 g/d increment) for metachronous colorectal (HR = 1.07, 95% CI = 1.00-1.14), upper aero-digestive tract (UADT) (HR = 1.16, 95% CI = 1.00-1.34) and kidney cancer (HR = 1.24, 95% CI = 1.10-1.39). Although these findings were partly explained by effects of smoking, the association for kidney cancer remained unchanged when current smokers or obese individuals were excluded. Alcohol intake trajectories over the life course confirmed associations with metachronous cancer risk. Prediagnosis long-term alcohol intake, and particularly heavy drinking, may increase the risk of metachronous cancer, particularly of the colorectum, UADT and kidney.
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| 55. |
- Jung, Audrey Y, et al.
(författare)
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Distinct reproductive risk profiles for intrinsic-like breast cancer subtypes : pooled analysis of population-based studies
- 2022
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Ingår i: Journal of the National Cancer Institute. - : Oxford University Press. - 0027-8874 .- 1460-2105. ; 114:12, s. 1706-1719
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Reproductive factors have been shown to be differentially associated with risk of estrogen receptor (ER) positive and ER-negative breast cancer. However, their associations with intrinsic-like subtypes are less clear.METHODS: Analyses included up to 23,353 cases, and 71,072 controls pooled from 31 population-based case-control or cohort studies in the Breast Cancer Association Consortium across 16 countries on 4 continents. Polytomous logistic regression was used to estimate the association between reproductive factors and risk of breast cancer by intrinsic-like subtypes (luminal A-like, luminal B-like, luminal B-HER2-like, HER2-enriched-like, and triple-negative) and by invasiveness. All statistical tests were 2-sided.RESULTS: Compared to nulliparous women, parous women had a lower risk of luminal A-like, luminal B-like, luminal B-HER2-like and HER2-enriched-like disease. This association was apparent only after approximately 10 years since last birth and became stronger with increasing time (odds ratio [OR] = 0.59, 95% confidence interval [CI] = 0.49 to 0.71; and OR = 0.36, 95% CI = 0.28 to 0.46; for multiparous women with luminal A-like tumors 20-<25 years after last birth and 45-<50 years after last birth, respectively). In contrast, parous women had a higher risk of triple-negative breast cancer right after their last birth (for multiparous women: OR = 3.12, 95%CI = 2.02 to 4.83) that was attenuated with time but persisted for decades (OR = 1.03, 95%CI = 0.79 to 1.34, for multiparous women 25 to < 30 years after last birth). Older age at first birth (P-heterogeneity<.001 for triple-negative compared to luminal-A like) and breastfeeding (P-heterogeneity<.001 for triple-negative compared to luminal-A like) were associated with lower risk of triple-negative but not with other disease subtypes. Younger age at menarche was associated with higher risk of all subtypes; older age at menopause was associated with higher risk of luminal A-like but not triple-negative breast cancer. Associations for in situ tumors were similar to luminal A-like.CONCLUSION: This large and comprehensive study demonstrates a distinct reproductive risk factor profile for triple-negative breast cancer compared to other subtypes, with implications for the understanding of disease etiology and risk prediction.
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| 56. |
- Labadie, Julia D., et al.
(författare)
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Genome-wide association study identifies tumor anatomical site-specific risk variants for colorectal cancer survival
- 2022
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Ingår i: Scientific Reports. - : Nature Publishing Group. - 2045-2322. ; 12:1
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Tidskriftsartikel (refereegranskat)abstract
- Identification of new genetic markers may improve the prediction of colorectal cancer prognosis. Our objective was to examine genome-wide associations of germline genetic variants with disease-specific survival in an analysis of 16,964 cases of colorectal cancer. We analyzed genotype and colorectal cancer-specific survival data from a consortium of 15 studies. Approximately 7.5 million SNPs were examined under the log-additive model using Cox proportional hazards models, adjusting for clinical factors and principal components. Additionally, we ran secondary analyses stratifying by tumor site and disease stage. We used a genome-wide p-value threshold of 5 × 10–8 to assess statistical significance. No variants were statistically significantly associated with disease-specific survival in the full case analysis or in the stage-stratified analyses. Three SNPs were statistically significantly associated with disease-specific survival for cases with tumors located in the distal colon (rs698022, HR = 1.48, CI 1.30–1.69, p = 8.47 × 10–9) and the proximal colon (rs189655236, HR = 2.14, 95% CI 1.65–2.77, p = 9.19 × 10–9 and rs144717887, HR = 2.01, 95% CI 1.57–2.58, p = 3.14 × 10–8), whereas no associations were detected for rectal tumors. Findings from this large genome-wide association study highlight the potential for anatomical-site-stratified genome-wide studies to identify germline genetic risk variants associated with colorectal cancer-specific survival. Larger sample sizes and further replication efforts are needed to more fully interpret these findings.
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| 57. |
- Labadie, Julia D., et al.
(författare)
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Postmenopausal Hormone Therapy and Colorectal Cancer Risk by Molecularly Defined Subtypes and Tumor Location
- 2020
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Ingår i: JNCI Cancer Spectrum. - : Oxford University Press. - 2515-5091. ; 4:5
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Tidskriftsartikel (refereegranskat)abstract
- Background: Postmenopausal hormone therapy (HT) is associated with a decreased colorectal cancer (CRC) risk. As CRC is a heterogeneous disease, we evaluated whether the association of HT and CRC differs across etiologically relevant, molecularly defined tumor subtypes and tumor location. Methods: We pooled data on tumor subtypes (microsatellite instability status, CpG island methylator phenotype status, BRAF and KRAS mutations, pathway: adenoma-carcinoma, alternate, serrated), tumor location (proximal colon, distal colon, rectum), and HT use among 8220 postmenopausal women (3898 CRC cases and 4322 controls) from 8 observational studies. We used multinomial logistic regression to estimate odds ratios (OR) and 95% confidence intervals (CIs) for the association of ever vs never HT use with each tumor subtype compared with controls. Models were adjusted for study, age, body mass index, smoking status, and CRC family history. All statistical tests were 2sided. Results: Among postmenopausal women, ever HT use was associated with a 38% reduction in overall CRC risk (OR = 0.62, 95% CI = 0.56 to 0.69). This association was similar according to microsatellite instability, CpG island methylator phenotype and BRAF or KRAS status. However, the association was attenuated for tumors arising through the serrated pathway (OR = 0.81, 95% CI = 0.66 to 1.01) compared with the adenoma-carcinoma pathway (OR = 0.63, 95% CI = 0.55 to 0.73; P-het =.04) and alternate pathway (OR = 0.61, 95% CI = 0.51 to 0.72). Additionally, proximal colon tumors had a weaker association (OR = 0.71, 95% CI = 0.62 to 0.80) compared with rectal (OR = 0.54, 95% CI = 0.46 to 0.63) and distal colon (OR = 0.57, 95% CI = 0.49 to 0.66; P-het = .01) tumors. Conclusions: We observed a strong inverse association between HT use and overall CRC risk, which may predominantly reflect a benefit of HT use for tumors arising through the adenoma-carcinoma and alternate pathways as well as distal colon and rectal tumors.
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| 58. |
- McNabb, Sarah, et al.
(författare)
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Meta-analysis of 16 studies of the association of alcohol with colorectal cancer
- 2020
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Ingår i: International Journal of Cancer. - : Wiley. - 0020-7136 .- 1097-0215. ; 146:3, s. 861-873
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Tidskriftsartikel (refereegranskat)abstract
- Alcohol consumption is an established risk factor for colorectal cancer (CRC). However, while studies have consistently reported elevated risk of CRC among heavy drinkers, associations at moderate levels of alcohol consumption are less clear. We conducted a combined analysis of 16 studies of CRC to examine the shape of the alcohol-CRC association, investigate potential effect modifiers of the association, and examine differential effects of alcohol consumption by cancer anatomic site and stage. We collected information on alcohol consumption for 14,276 CRC cases and 15,802 controls from 5 case-control and 11 nested case-control studies of CRC. We compared adjusted logistic regression models with linear and restricted cubic splines to select a model that best fit the association between alcohol consumption and CRC. Study-specific results were pooled using fixed-effects meta-analysis. Compared to non-/occasional drinking (<= 1 g/day), light/moderate drinking (up to 2 drinks/day) was associated with a decreased risk of CRC (odds ratio [OR]: 0.92, 95% confidence interval [CI]: 0.88-0.98, p = 0.005), heavy drinking (2-3 drinks/day) was not significantly associated with CRC risk (OR: 1.11, 95% CI: 0.99-1.24, p = 0.08) and very heavy drinking (more than 3 drinks/day) was associated with a significant increased risk (OR: 1.25, 95% CI: 1.11-1.40, p < 0.001). We observed no evidence of interactions with lifestyle risk factors or of differences by cancer site or stage. These results provide further evidence that there is a J-shaped association between alcohol consumption and CRC risk. This overall pattern was not significantly modified by other CRC risk factors and there was no effect heterogeneity by tumor site or stage.
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| 59. |
- Midttun, Øivind, et al.
(författare)
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A cross-sectional study of inflammatory markers as determinants of circulating kynurenines in the Lung Cancer Cohort Consortium
- 2023
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Ingår i: Scientific Reports. - : Springer Nature. - 2045-2322. ; 13:1
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Tidskriftsartikel (refereegranskat)abstract
- Circulating concentrations of metabolites (collectively called kynurenines) in the kynurenine pathway of tryptophan metabolism increase during inflammation, particularly in response to interferon-gamma (IFN-γ). Neopterin and the kynurenine/tryptophan ratio (KTR) are IFN-γ induced inflammatory markers, and together with C-reactive protein (CRP) and kynurenines they are associated with various diseases, but comprehensive data on the strength of associations of inflammatory markers with circulating concentrations of kynurenines are lacking. We measured circulating concentrations of neopterin, CRP, tryptophan and seven kynurenines in 5314 controls from 20 cohorts in the Lung Cancer Cohort Consortium (LC3). The associations of neopterin, KTR and CRP with kynurenines were investigated using regression models. In mixed models, one standard deviation (SD) higher KTR was associated with a 0.46 SD higher quinolinic acid (QA), and 0.31 SD higher 3-hydroxykynurenine (HK). One SD higher neopterin was associated with 0.48, 0.44, 0.36 and 0.28 SD higher KTR, QA, kynurenine and HK, respectively. KTR and neopterin respectively explained 24.1% and 16.7% of the variation in QA, and 11.4% and 7.5% of HK. CRP was only weakly associated with kynurenines in regression models. In summary, QA was the metabolite that was most strongly associated with the inflammatory markers. In general, the inflammatory markers were most strongly related to metabolites located along the tryptophan-NAD axis, which may support suggestions of increased production of NAD from tryptophan during inflammation.
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| 60. |
- Papadimitriou, Nikos, et al.
(författare)
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Physical activity and risks of breast and colorectal cancer : a Mendelian randomisation analysis
- 2020
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Ingår i: Nature Communications. - : Springer Nature. - 2041-1723. ; 11:1
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Tidskriftsartikel (refereegranskat)abstract
- Physical activity has been associated with lower risks of breast and colorectal cancer in epidemiological studies; however, it is unknown if these associations are causal or confounded. In two-sample Mendelian randomisation analyses, using summary genetic data from the UK Biobank and GWA consortia, we found that a one standard deviation increment in average acceleration was associated with lower risks of breast cancer (odds ratio [OR]: 0.51, 95% confidence interval [CI]: 0.27 to 0.98, P-value=0.04) and colorectal cancer (OR: 0.66, 95% CI: 0.48 to 0.90, P-value=0.01). We found similar magnitude inverse associations for estrogen positive (ER+ve) breast cancer and for colon cancer. Our results support a potentially causal relationship between higher physical activity levels and lower risks of breast cancer and colorectal cancer. Based on these data, the promotion of physical activity is probably an effective strategy in the primary prevention of these commonly diagnosed cancers. Physical activity has been linked to lower risks of colorectal and breast cancer. Here, the authors present a Mendelian randomisation analysis supporting a potentially causal relationship between higher physical activity levels and lower risks of breast cancer and colorectal cancer.
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