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1.
Proc Natl Acad Sci U S A ; 119(18): e2117464119, 2022 05 03.
Artículo en Inglés | MEDLINE | ID: mdl-35476522

RESUMEN

As northern latitudes experience rapid winter warming, there is an urgent need to assess the effect of varying winter conditions on tree growth and forest carbon sequestration potential. We examined tree growth responses to variability in cold-season (November­April) frequency of freeze days (FFD) over 1951 to 2018 using tree-ring data from 35,217 trees and 57 species at 4,375 sites distributed across Canada. We found that annual radial growth responses to FFD varied by species, with some commonalities across genera and clades. The growth of gymnosperms with late spring leaf-out strategies was negatively related to FFD; years with high FFD were most detrimental to the annual growth of Pinus banksiana, Pinus contorta, Larix lyalli, Abies amabilis, and Abies lasiocarpa. In contrast, the growth of angiosperms with early leaf-out strategies, namely, Populus tremuloides and Betula papyrifera, was better in the coldest years, and gymnosperms with intermediate leaf-out timing, such as widespread Picea mariana and Picea glauca, had no consistent relationship to FFD. Tree growth responses to FFD were further modulated by tree size, tree age, regional climate (i.e., mean cold-season temperature), and local site conditions. Overall, our results suggest that moderately warming winters may temporarily improve the growth of widespread pines and some high-elevation conifers in western Canada, whereas warming winters may be detrimental to the growth of widespread boreal angiosperms. Our findings also highlight the value of using species-specific climate-growth relationships to refine predictions of forest carbon dynamics.


Asunto(s)
Bosques , Árboles , Secuestro de Carbono , Cambio Climático , Estaciones del Año
2.
Breast Cancer Res Treat ; 196(1): 45-56, 2022 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-36056297

RESUMEN

INTRODUCTION: Triple-negative breast cancer (TNBC) is known for its aggressive behaviors and lacking of effective treatment. Programmed cell death ligand-1 (PD-L1) inhibitor has just been approved for using in the management of advanced TNBC. To accurately screen TNBC sensitive to anti-PD-L1 treatment and to explore the feasibility of the ataxia-telangiectasia mutation protein (ATM) inhibitor combined with PD-L1 inhibitor, radiotherapy and chemotherapy, we focus on whether ATM participates in the regulation of PD-L1 and affects the prognosis of patients through c-Src, signal transducer and activator of transcription 1&3 (STAT1 and STAT3). MATERIALS AND METHODS: We used immunohistochemical staining to explore the relationship of ATM with c-Src, STAT1, STAT3, PD-1/PD-L1, Tumor-infiltrating lymphocytes (TILs), as well as other clinicopathologic features in 86 pathological stage III TNBCs. Their impact on prognosis was also explored. RESULTS: We found ATM expression was negatively correlated with STAT1, STAT3, PD-L1, TILs and CD8 + cells in TNBC. STAT1 positively correlated the expression of PD-L1. In TNBC with ATM low expression, STAT3 was an independent factor for improved prognosis, while PD-L1 was an independent negative prognostic factor. Furthermore, in low ATM group, the phosphorylation of tyrosine at position 419 of c-Src (p-c-src Y419) was correlated with the overexpression of STAT3. CONCLUSION: Locally advanced TNBC with low ATM expression may be more likely to benefit from anti-PD-L1 inhibitors. The feasibility of ATM functional inhibitor combined with immune checkpoint blockade therapies in the treatment of TNBC is also worthy of further exploration. Our study suggests that STAT3 has different impacts on tumor progression in different tumors.


Asunto(s)
Neoplasias de la Mama Triple Negativas , Proteínas de la Ataxia Telangiectasia Mutada/genética , Proteínas de la Ataxia Telangiectasia Mutada/metabolismo , Antígeno B7-H1/genética , Antígeno B7-H1/metabolismo , Biomarcadores de Tumor/metabolismo , Humanos , Inhibidores de Puntos de Control Inmunológico , Ligandos , Linfocitos Infiltrantes de Tumor , Mutación , Pronóstico , Receptor de Muerte Celular Programada 1/metabolismo , Factor de Transcripción STAT1/genética , Factor de Transcripción STAT1/metabolismo , Factor de Transcripción STAT3/genética , Factor de Transcripción STAT3/metabolismo , Neoplasias de la Mama Triple Negativas/tratamiento farmacológico , Neoplasias de la Mama Triple Negativas/terapia , Tirosina/metabolismo
3.
Breast Cancer Res Treat ; 180(2): 311-319, 2020 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-31993861

RESUMEN

INTRODUCTION: Triple negative breast cancer (TNBC) is an aggressive cancer subtype and lack of effective targeted therapies. It has been recently reported that Interleukin 17 (IL-17), a family of cytokines secreted in tumor microenvironment, affects tumor progression through a variety of molecular pathways. Its role in TNBC is so far still poorly explored. MATERIALS AND METHODS: We employed immunohistochemistry to evaluate the distribution of IL-17+ cells in TNBC with no special type features (TNBC-NST), their association with tumor microangiogenesis, as well as their impact on prognosis of the patients. RESULTS: In comparison to medullary carcinoma with triple-negative molecular features (TNBC-MC), we found a significant increase in IL-17+ cell infiltrates in intratumoral stroma and extratumoral stroma of TNBC-NST. Similarly, stromal cells with co-expression of CD4 and IL-17 were noted in intratumoral and extratumoral stroma in both TNBC-NST and TNBC-MC. In addition, intratumoral IL-17+ cells were positively associated with tumor cell expression of vascular endothelial growth factor A (VEGFA) and with intratumoral tumor microvascular density (MVD). Multivariate analysis identified that intratumoral IL-17+ cells (P = 0.018), MVD (P = 0.039), and TNM stage (P = 0.002) were independent prognostic factors for predicting poor PFS. CONCLUSION: The study indicates that IL-17 is overexpressed in intratumoral stromal cells of TNBC-NST. The overexpression of IL-17 might engage in active tumor microangiogenesis through its signal transduction pathways resulting in increased tumor secretion of VEGFA, and then promote tumor progression. IL-17 might serve as a potential new target for individualized therapy to TNBC-NST patients by development of specific antibodies. Additional study is deemed to further explore the role of IL-17+ stromal cells in breast cancer.


Asunto(s)
Biomarcadores de Tumor/metabolismo , Interleucina-17/metabolismo , Neovascularización Patológica , Células del Estroma/inmunología , Neoplasias de la Mama Triple Negativas/patología , Microambiente Tumoral/inmunología , Factor A de Crecimiento Endotelial Vascular/metabolismo , Femenino , Humanos , Pronóstico , Transducción de Señal , Células del Estroma/metabolismo , Células del Estroma/patología , Tasa de Supervivencia , Neoplasias de la Mama Triple Negativas/inmunología , Neoplasias de la Mama Triple Negativas/metabolismo
4.
Proc Natl Acad Sci U S A ; 113(52): E8406-E8414, 2016 12 27.
Artículo en Inglés | MEDLINE | ID: mdl-27956624

RESUMEN

Considerable evidence exists that current global temperatures are higher than at any time during the past millennium. However, the long-term impacts of rising temperatures and associated shifts in the hydrological cycle on the productivity of ecosystems remain poorly understood for mid to high northern latitudes. Here, we quantify species-specific spatiotemporal variability in terrestrial aboveground biomass stem growth across Canada's boreal forests from 1950 to the present. We use 873 newly developed tree-ring chronologies from Canada's National Forest Inventory, representing an unprecedented degree of sampling standardization for a large-scale dendrochronological study. We find significant regional- and species-related trends in growth, but the positive and negative trends compensate each other to yield no strong overall trend in forest growth when averaged across the Canadian boreal forest. The spatial patterns of growth trends identified in our analysis were to some extent coherent with trends estimated by remote sensing, but there are wide areas where remote-sensing information did not match the forest growth trends. Quantifications of tree growth variability as a function of climate factors and atmospheric CO2 concentration reveal strong negative temperature and positive moisture controls on spatial patterns of tree growth rates, emphasizing the ecological sensitivity to regime shifts in the hydrological cycle. An enhanced dependence of forest growth on soil moisture during the late-20th century coincides with a rapid rise in summer temperatures and occurs despite potential compensating effects from increased atmospheric CO2 concentration.


Asunto(s)
Dióxido de Carbono/química , Cambio Climático , Bosques , Árboles/crecimiento & desarrollo , Biomasa , Canadá , Ciclo del Carbono , Ecología , Geografía , Modelos Estadísticos , Análisis de Regresión , Taiga , Temperatura , Factores de Tiempo
5.
Breast Cancer Res Treat ; 159(1): 31-9, 2016 08.
Artículo en Inglés | MEDLINE | ID: mdl-27455837

RESUMEN

Dual-probe fluorescence in situ hybridization (D-FISH) is a widely accepted method to determine the gene amplification status of human epidermal growth factor receptor 2 (Her-2). In 2013, the American Society of Clinical Oncology/College of American Pathologists (ASCO/CAP) updated the guidelines on the Her-2 testing for invasive breast cancer (BCa). The interpretation criteria for D-FISH changed accordingly. In this study, we compared the Her-2 FISH statuses based on the 2013 and 2007 ASCO/CAP guidelines in 1931 cases of BCa with Her-2 D-FISH testing at our hospital. We analyzed the clinicopathologic features of cases with equivocal results by the 2013 ASCO/CAP guidelines. Although the guideline update significantly improved the detection rate of Her-2 amplification, it also significantly increased the rate of equivocal results, posing a dilemma for clinical management. The equivocal results had a good reproducibility. The distribution of D-FISH-equivocal cases did not correlate with Her-2 status by immunohistochemistry, suggesting that Her-2 D-FISH equivocality may not reflect Her-2 overexpression. Compared with Her-2-negative cases by D-FISH, Her-2 D-FISH-equivocal cases had higher Ki67 expression, higher histological grade, more frequent lymph node metastasis, and lower estrogen receptor α expression, indicating a group of BCa with worse prognosis. The clinical significance of Her-2-equivocal results by D-FISH warrants further investigation.


Asunto(s)
Neoplasias de la Mama/diagnóstico , Amplificación de Genes , Receptor ErbB-2/genética , Neoplasias de la Mama/genética , Neoplasias de la Mama/metabolismo , Centrómero/genética , Cromosomas Humanos Par 17/genética , Femenino , Humanos , Hibridación Fluorescente in Situ , Guías de Práctica Clínica como Asunto , Receptor ErbB-2/metabolismo , Sensibilidad y Especificidad
6.
Glob Chang Biol ; 22(2): 627-43, 2016 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-26507106

RESUMEN

An increasing number of studies conclude that water limitations and heat stress may hinder the capacity of black spruce (Picea mariana (Mill.) B.S.P.) trees, a dominant species of Canada's boreal forests, to grow and assimilate atmospheric carbon. However, there is currently no scientific consensus on the future of these forests over the next century in the context of widespread climate warming. The large spatial extent of black spruce forests across the Canadian boreal forest and associated variability in climate, demography, and site conditions pose challenges for projecting future climate change responses. Here we provide an evaluation of the impacts of climate warming and drying, as well as increasing [CO2 ], on the aboveground productivity of black spruce forests across Canada south of 60°N for the period 1971 to 2100. We use a new extensive network of tree-ring data obtained from Canada's National Forest Inventory, spatially explicit simulations of net primary productivity (NPP) and its drivers, and multivariate statistical modeling. We found that soil water availability is a significant driver of black spruce interannual variability in productivity across broad areas of the western to eastern Canadian boreal forest. Interannual variability in productivity was also found to be driven by autotrophic respiration in the warmest regions. In most regions, the impacts of soil water availability and respiration on interannual variability in productivity occurred during the phase of carbohydrate accumulation the year preceding tree-ring formation. Results from projections suggest an increase in the importance of soil water availability and respiration as limiting factors on NPP over the next century due to warming, but this response may vary to the extent that other factors such as carbon dioxide fertilization, and respiration acclimation to high temperature, contribute to dampening these limitations.


Asunto(s)
Cambio Climático , Modelos Teóricos , Picea/crecimiento & desarrollo , Canadá , Dióxido de Carbono , Clima , Suelo/química , Taiga , Temperatura , Agua/análisis
7.
Pharmacoepidemiol Drug Saf ; 24(9): 962-70, 2015 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-26095121

RESUMEN

PURPOSE: Statistical shrinkage is a potential statistical method to improve the accuracy of signal detection results and avoid spurious associations detected by disproportionality analyses. In this study, we introduced statistical shrinkage influence on disproportionality methods in spontaneous reporting system in China. METHODS: We added the shrinkage parameters in the numerator and denominator, denoted as in the formula of disproportionality analysis. The shrinkage parameters were subjectively set to between 0 and 5, with an interval of 0.1. Adverse drug reaction product label database was deemed as a proxy of golden standard to evaluate the effect of statistical shrinkage. Reports in the years of 2010-2011 were extracted from the national spontaneous reporting system database as the data source for analysis in this study. RESULTS: When α was around 0.5, the Youden index reached the maximum for each disproportionality methods in this study. The value of 0.6 was suggested as the most appropriate statistical shrinkage parameter for reporting odds ratio and proportional reporting ratio and 0.2 for information component based on the spontaneous reporting system of China.


Asunto(s)
Sistemas de Registro de Reacción Adversa a Medicamentos/estadística & datos numéricos , Bases de Datos Factuales/estadística & datos numéricos , Farmacovigilancia , Algoritmos , China/epidemiología , Efectos Colaterales y Reacciones Adversas Relacionados con Medicamentos/epidemiología , Humanos , Oportunidad Relativa
8.
Clin Infect Dis ; 58(8): 1116-24, 2014 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-24550376

RESUMEN

BACKGROUND: Algorithms for the diagnosis of syphilis continue to be a source of great controversy, and numerous test interpretations have perplexed many clinicians. METHODS: We conducted a cross-sectional study of 24 124 subjects to analyze 3 syphilis testing algorithms: traditional algorithm, reverse algorithm, and the European Centre for Disease Prevention and Control (ECDC) algorithm. Every serum sample was simultaneously evaluated using the rapid plasma reagin, Treponema pallidum particle agglutination, and chemiluminescence immunoassay tests. With the results of clinical diagnoses of syphilis as a gold standard, we evaluated the diagnostic accuracy of the 3 syphilis testing algorithms. The κ coefficient was used to compare the concordance between the reverse algorithm and the ECDC algorithm. RESULTS: Overall, 2749 patients in our cohort were diagnosed with syphilis. The traditional algorithm had the highest negative likelihood ratio (0.24), a missed diagnosis rate of 24.2%, and only 75.81% sensitivity. However, both the reverse and ECDC algorithms had higher diagnostic efficacy than the traditional algorithm. Their sensitivity, specificity, and accuracy were 99.38%-99.85%, 99.98%-100.00%, and 99.93%-99.96%, respectively. Moreover, the overall percentage of agreement and κ value between the reverse and the ECDC algorithms were 99.9% and 0.996, respectively. CONCLUSIONS: Our research supported use of the ECDC algorithm, in which syphilis screening begins with a treponemal immunoassay that is followed by a second, different treponemal assay as a confirmatory test in high-prevalence populations. In addition, our results indicated that nontreponemal assay is unnecessary for syphilis diagnosis but can be recommended for determining serological activity and the effect of syphilis treatment.


Asunto(s)
Serodiagnóstico de la Sífilis/métodos , Treponema pallidum/inmunología , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Algoritmos , Niño , Preescolar , Estudios Transversales , Femenino , Humanos , Lactante , Masculino , Persona de Mediana Edad , Sensibilidad y Especificidad , Suero/inmunología , Adulto Joven
9.
Clin Infect Dis ; 59(3): 384-9, 2014 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-24803377

RESUMEN

BACKGROUND: The prozone phenomenon is known to be associated with high antibody titers; other associations, such as host factors, have not been elucidated. METHODS: A retrospective analysis was conducted to evaluate the incidence of the prozone phenomenon of the syphilis rapid plasma reagin (RPR) test among 46 856 clinical samples, between June 2010 and June 2013. Logistic regression was used to analyze the risk factors of the prozone phenomenon. RESULTS: Our results showed that the incidence of the prozone phenomenon was low (0.83%) and could occur during any clinical phase, particularly during primary and secondary syphilis. Pregnancy and neurosyphilis were associated with the prozone phenomenon; sex, age, and whether the patient had been treated were not. The results also revealed that the prozone phenomenon not only occurred in patients with a high titer but also could occur in patients with a moderate/low titer. In fact, almost 31% of the patients with the prozone phenomenon had titers ≤1:16. CONCLUSIONS: The prozone phenomenon in the RPR test was associated with the phase of syphilis, pregnancy, and neurosyphilis as well as a range of RPR titers between 1:8 and 1:512. This latter finding is in contrast to previous reports that the prozone phenomenon is associated with very high RPR titers.


Asunto(s)
Reaginas/sangre , Sífilis/diagnóstico , Adolescente , Adulto , Anciano , Pruebas de Aglutinación , Niño , Preescolar , Estudios de Cohortes , Femenino , Humanos , Incidencia , Lactante , Recién Nacido , Masculino , Persona de Mediana Edad , Embarazo , Estudios Retrospectivos , Factores de Riesgo , Serodiagnóstico de la Sífilis , Adulto Joven
10.
Glob Chang Biol ; 20(3): 851-66, 2014 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-24115302

RESUMEN

The 20th century was a pivotal period at high northern latitudes as it marked the onset of rapid climatic warming brought on by major anthropogenic changes in global atmospheric composition. In parallel, Arctic sea ice extent has been decreasing over the period of available satellite data records. Here, we document how these changes influenced vegetation productivity in adjacent eastern boreal North America. To do this, we used normalized difference vegetation index (NDVI) data, model simulations of net primary productivity (NPP) and tree-ring width measurements covering the last 300 years. Climatic and proxy-climatic data sets were used to explore the relationships between vegetation productivity and Arctic sea ice concentration and extent, and temperatures. Results indicate that an unusually large number of black spruce (Picea mariana) trees entered into a period of growth decline during the late-20th century (62% of sampled trees; n = 724 cross sections of age >70 years). This finding is coherent with evidence encoded in NDVI and simulated NPP data. Analyses of climatic and vegetation productivity relationships indicate that the influence of recent climatic changes in the studied forests has been via the enhanced moisture stress (i.e. greater water demands) and autotrophic respiration amplified by the declining sea ice concentration in Hudson Bay and Hudson Strait. The recent decline strongly contrasts with other growth reduction events that occurred during the 19th century, which were associated with cooling and high sea ice severity. The recent decline of vegetation productivity is the first one to occur under circumstances related to excess heat in a 300-year period, and further culminates with an intensifying wildfire regime in the region. Our results concur with observations from other forest ecosystems about intensifying temperature-driven drought stress and tree mortality with ongoing climatic changes.


Asunto(s)
Cambio Climático , Cubierta de Hielo , Picea/crecimiento & desarrollo , Árboles/crecimiento & desarrollo , América del Norte
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