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51.
Tovi Lehmann Douglas H Graham Erica R Dahl Lilian M G Bahia-Oliveira S M Gennari J P Dubey 《Infection, genetics and evolution》2004,4(2):107-114
Previous studies of Toxoplasma gondii, based on samples dominated by clinical isolates, have concluded that its population structure is clonal, despite the sexual reproduction that occurs in cats. To determine whether this applies to non-clinical isolates, we compared patterns of linkage disequilibrium (LD) among seven loci in samples of T. gondii from Brazil and the US. LD was detected in both locations, but it was substantially lower in Brazil. The lower LD in Brazil can be explained by a higher rate of sexual reproduction between different genotypes (outcrossing) because of a higher rate of transmission. The extent of LD between pairs of physically unlinked loci varied significantly in each location. Moreover, the magnitude of LD between corresponding locus pairs in Brazil and the US was correlated, despite minimal gene exchange between the continents (mean FST = 0.19). The heterogeneity among locus pairs and the correlation in LD between physically unlinked locus pairs from different continents suggests that locus-specific factors, such as epistatic selection are involved in maintaining LD in T. gondii. Possibly, the unique life cycle of T. gondii with its unpredictable transmission among diverse host species and distinct ecological habitats requires specific combinations of alleles from multiple loci. The usefulness of typing isolates based on physically unlinked loci is questioned not only by the geographic variation in the reproductive population structure, but mainly by the low overall predictability of the genotype of one locus based on the genotype in another (unlinked) locus. This predictability ranged between 23 and 45%, but was close to nil for a considerable fraction of locus pairs. 相似文献
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Brian L Sprague Amy Trentham-Dietz Curtis J Hedman Jue Wang Jocelyn DC Hemming John M Hampton Diana SM Buist Erin J Aiello Bowles Gale S Sisney Elizabeth S Burnside 《Breast cancer research : BCR》2013,15(3):R45
Introduction
Humans are widely exposed to estrogenically active phthalates, parabens, and phenols, raising concerns about potential effects on breast tissue and breast cancer risk. We sought to determine the association of circulating serum levels of these chemicals (reflecting recent exposure) with mammographic breast density (a marker of breast cancer risk).Methods
We recruited postmenopausal women aged 55 to 70 years from mammography clinics in Madison, Wisconsin (N = 264). Subjects completed a questionnaire and provided a blood sample that was analyzed for mono-ethyl phthalate, mono-butyl phthalate, mono-benzyl phthalate, butyl paraben, propyl paraben, octylphenol, nonylphenol, and bisphenol A (BPA). Percentage breast density was measured from mammograms by using a computer-assisted thresholding method.Results
Serum BPA was positively associated with mammographic breast density after adjusting for age, body mass index, and other potentially confounding factors. Mean percentage density was 12.6% (95% confidence interval (CI), 11.4 to 14.0) among the 193 women with nondetectable BPA levels, 13.7% (95% CI, 10.7 to 17.1) among the 35 women with detectable levels below the median (<0.55 ng/ml), and 17.6% (95% CI, 14.1 to 21.5) among the 34 women with detectable levels above the median (>0.55 ng/ml; Ptrend = 0.01). Percentage breast density was also elevated (18.2%; 95% CI, 13.4 to 23.7) among the 18 women with serum mono-ethyl phthalate above the median detected level (>3.77 ng/ml) compared with women with nondetectable BPA levels (13.1%; 95% CI, 11.9 to 14.3; Ptrend = 0.07). No other chemicals demonstrated associations with percentage breast density.Conclusions
Postmenopausal women with high serum levels of BPA and mono-ethyl phthalate had elevated breast density. Further investigation of the impact of BPA and mono-ethyl phthalate on breast cancer risk by using repeated serum measurements or other markers of xenoestrogen exposure are needed. 相似文献55.
Alessio Cortellini Juan Aguilar-Company Ramon Salazar Mark Bower Ailsa Sita-Lumsden Andrea Plaja Alvin J. X. Lee Alexia Bertuzzi Carlo Tondini Nikolaos Diamantis Clara Martinez-Vila Aleix Prat Eleanor Apthorp Alessandra Gennari David J. Pinato 《British journal of cancer》2022,127(10):1787
Background Consolidated evidence suggests spontaneous immunity from SARS-CoV-2 is not durable, leading to the risk of reinfection, especially in the context of newly emerging viral strains. In patients with cancer who survive COVID-19 prevalence and severity of SARS-CoV-2 reinfections are unknown.Methods We aimed to document natural history and outcome from SARS-CoV-2 reinfection in patients recruited to OnCovid (), an active European registry enrolling consecutive patients with a history of solid or haematologic malignancy diagnosed with COVID-19.Results As of December 2021, out of 3108 eligible participants, 1806 COVID-19 survivors were subsequently followed at participating institutions. Among them, 34 reinfections (1.9%) were reported after a median time of 152 days (range: 40–620) from the first COVID-19 diagnosis, and with a median observation period from the second infection of 115 days (95% CI: 27–196). Most of the first infections were diagnosed in 2020 (27, 79.4%), while most of reinfections in 2021 (25, 73.5%). Haematological malignancies were the most frequent primary tumour (12, 35%). Compared to first infections, second infections had lower prevalence of COVID-19 symptoms (52.9% vs 91.2%, P = 0.0008) and required less COVID-19-specific therapy (11.8% vs 50%, P = 0.0013). Overall, 11 patients (32.4%) and 3 (8.8%) were fully and partially vaccinated against SARS-CoV-2 before the second infection, respectively. The 14-day case fatality rate was 11.8%, with four death events, none of which among fully vaccinated patients.Conclusion This study shows that reinfections in COVID-19 survivors with cancer are possible and more common in patients with haematological malignancies. Reinfections carry a 11% risk of mortality, which rises to 15% among unvaccinated patients, highlighting the importance of universal vaccination of patients with cancer.Subject terms: NCT04393974Oncology, Public health 相似文献
56.
Paulina M Kowalewska Jacob Fletcher William F Jackson Suzanne E Brett Michelle SM Kim Galina Yu Mironova Nadia Haghbin David M Richter Nathan R Tykocki Mark T Nelson Donald G Welsh 《Journal of cerebral blood flow and metabolism》2022,42(9):1693
Cerebral blood flow is a finely tuned process dependent on coordinated changes in arterial tone. These changes are strongly tied to smooth muscle membrane potential and inwardly rectifying K+ (KIR) channels are thought to be a key determinant. To elucidate the role of KIR2.1 in cerebral arterial tone development, this study examined the electrical and functional properties of cells, vessels and living tissue from tamoxifen-induced smooth muscle cell (SMC)-specific KIR2.1 knockout mice. Patch-clamp electrophysiology revealed a robust Ba2+-sensitive inwardly rectifying K+ current in cerebral arterial myocytes irrespective of KIR2.1 knockout. Immunolabeling clarified that KIR2.1 expression was low in SMCs while KIR2.2 labeling was remarkably abundant at the membrane. In alignment with these observations, pressure myography revealed that the myogenic response and K+-induced dilation were intact in cerebral arteries post knockout. At the whole organ level, this translated to a maintenance of brain perfusion in SMC KIR2.1−/− mice, as assessed with arterial spin-labeling MRI. We confirmed these findings in superior epigastric arteries and implicated KIR2.2 as more functionally relevant in SMCs. Together, these results suggest that subunits other than KIR2.1 play a significant role in setting native current in SMCs and driving arterial tone. 相似文献
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Marco Gennari Andrea Annoni Marco Agrifoglio 《The international journal of cardiovascular imaging》2016,32(4):659-660
Acute aortic dissection is a life-threatening conditions with a high mortality rate within the first 24 h since presentation, if left untreated. Nevertheless the setting may be chronic and stable. We present a rare case of a misdiagnosed and unoperated Stanford type A aortic dissection in a 78-year old woman with stable computed tomography features at the second year of clinical follow-up. 相似文献
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