Identification of air mass responsible for warm events at Syowa station

第6回極域科学シンポジウム[OM] 極域気水圏11月16日（月）　統計数理研究所 セミナー室2（D304

Identification of Air Masses Responsible for Warm Events on the East Antarctic Coast

International audienceWarm events, periods when rising surface air temperatures can trigger surface melt, have been recorded during the austral summer at Syowa station on the East Antarctic coast. This study identifies air masses responsible for summer warm events at Syowa. Air masses arriving at Syowa are classified into marine and glacial sources based on their isotopic characteristics. Warm events are not associated with moist marine air intrusion, but with the downward flow of dry glacial air along the west side slope of the mountains in Enderby Land (EL). We use simulations from the Antarctic Mesoscale Prediction System (AMPS) to explore the atmospheric process responsible for the warmest event at Syowa. The model output illustrates several foehn-associated features such as low-level blocking, precipitation on the mountain's windward side, and mountain wave activity, with warm air ascending on the upstream slope and descending to Syowa. The foehn warming is caused by an easterly cross-mountain flow associated with a low-pressure system to the north of the EL coast. Future changes in synoptic cyclonic activity off the EL coast may have a significant impact on the frequency and intensity of foehn events at Syowa and the associated coastal warm events

Influence of large-scale atmospheric circulation on marine air intrusion toward the East Antarctic coast

International audienceMarine air intrusions into Antarctica play a key role in high-precipitation events. Here we use shipboard observations of water vapor isotopologues between Australia and Syowa on the East Antarctic coast to elucidate the mechanism by which large-scale circulation influences marine air intrusions. The temporal isotopic variations at Syowa reflect the meridional movement of a marine air front. They are also associated with atmospheric circulation anomalies that enhance the southward movement of cyclones over the Southern Ocean. The relationship between large-scale circulation and the movement of the front is explained by northerly winds which, in association with cyclones, move toward the Antarctic coast and push marine air with isotopically enriched moisture into the inland covered by glacial air with depleted isotopic values. Future changes in large-scale circulation may have a significant impact on the frequency and intensity of marine air intrusion into Antarctica

Fatal case of Capnocytophaga sepsis from a dog bite in a patient with splenic hypoplasia

Abstract Background Capnocytophaga canimorsus is an oral commensal bacteria in dogs and may cause severe infection following a dog bite. This is a case of fatal C. canimorsus sepsis with acute infectious purpura fulminans (AIPF) in a healthy patient with splenic hypoplasia. Case Presentation A healthy 49‐year‐old man was admitted to the intensive care unit (ICU) for septic shock and AIPF 4 days after a dog bite to his mouth. Computed tomography revealed a small spleen measuring 53 cm3 but no other source of infection. Despite intensive care, the patient died of multiple organ failure and progressive shock on the fifth ICU day. Polymerase chain reaction of blood samples identified the C. canimorsus gene on a later day. Conclusion Capnocytophaga canimorsus from dog bites may cause fatal AIPF. Splenic hypoplasia and bite wounds in well‐perfused areas such as the oral cavity are possible risk factors for sepsis. All dog bites should warrant medical attention

Prognostic significance of myeloid immune cells and their spatial distribution in the colorectal cancer microenvironment

Background Myeloid cells represent an abundant yet heterogeneous cell population in the colorectal cancer microenvironment, and their roles remain poorly understood.Methods We used multiplexed immunofluorescence combined with digital image analysis to identify CD14+ monocytic and CD15+ granulocytic cells and to evaluate their maturity (HLA-DR and CD33), immunosuppressive potential (ARG1) and proximity to cytokeratin (KRT)-positive tumor cells in 913 colorectal carcinomas. Using covariate data of 4465 incident colorectal cancers in two prospective cohort studies, the inverse probability weighting method was used with multivariable-adjusted Cox proportional hazards models to assess cancer-specific mortality according to ordinal quartiles (Q1–Q4) of myeloid cell densities. Immune cell–tumor cell proximity was measured with the nearest neighbor method and the G-cross function, which determines the likelihood of any tumor cell having at least one immune cell of the specified type within a certain radius.Results Higher intraepithelial (Ptrend=0.0002; HR for Q4 (vs Q1), 0.48, 95% CI 0.31 to 0.76) and stromal (Ptrend <0.0001; HR for Q4 (vs Q1), 0.42, 95% CI 0.29 to 0.63) densities of CD14+HLA-DR+ cells were associated with lower colorectal cancer-specific mortality while, conversely, higher intraepithelial densities of CD14+HLA-DR− cells were associated with higher colorectal cancer-specific mortality (Ptrend=0.0003; HR for Q4 (vs Q1), 1.78, 95% CI 1.25 to 2.55). Spatial analyses indicated that CD15+ cells were located closer to tumor cells than CD14+ cells, and CD14+HLA-DR+ cells were closer to tumor than CD14+HLA-DR− cells (p<0.0001). The G-cross proximity measurement, evaluating the difference in the likelihood of any tumor cell being colocated with at least one CD14+HLA-DR+ cell versus CD14+HLA-DR− cell within a 20 µm radius, was associated with lower colorectal cancer-specific mortality (Ptrend <0.0001; HR for Q4 (vs Q1), 0.37, 95% CI 0.24 to 0.57).Conclusions Myeloid cell populations occur in spatially distinct distributions and exhibit divergent, subset-specific prognostic significance in colorectal cancer, with mature CD14+HLA-DR+ and immature CD14+HLA-DR− monocytic phenotypes most notably showing opposite associations. These results highlight the prognostic utility of multimarker evaluation of myeloid cell infiltrates and reveal a previously unrecognized degree of spatial organization for myeloid cells in the immune microenvironment

Desmoplastic reaction, immune cell response, and prognosis in colorectal cancer

Abstract Background: The relationships between tumor stromal features (such as desmoplastic reaction, myxoid stroma, and keloid-like collagen bundles) and immune cells in the colorectal carcinoma microenvironment have not yet been fully characterized. Methods: In 908 tumors with available tissue among 4,465 incident colorectal adenocarcinoma cases in two prospective cohort studies, we examined desmoplastic reaction, myxoid stroma, and keloid-like collagen bundles. We conducted multiplex immunofluorescence for T cells [CD3, CD4, CD8, CD45RO (PTPRC), and FOXP3] and for macrophages [CD68, CD86, IRF5, MAF, and MRC1 (CD206)]. We used the inverse probability weighting method and the 4,465 incident cancer cases to adjust for selection bias. Results: Immature desmoplastic reaction was associated with lower densities of intraepithelial CD3⁺CD8⁺CD45RO⁺ cells [multivariable odds ratio (OR) for the highest (vs. lowest) density category, 0.43; 95% confidence interval (CI), 0.29–0.62; Ptrend <0.0001] and stromal M1-like macrophages [the corresponding OR, 0.44; 95% CI, 0.28–0.70; Ptrend = 0.0011]. Similar relations were observed for myxoid stroma [intraepithelial CD3⁺CD8⁺CD45RO⁺ cells (Ptrend <0.0001) and stromal M1-like macrophages (Ptrend = 0.0007)] and for keloid-like collagen bundles (Ptrend <0.0001 for intraepithelial CD3⁺CD8⁺CD45RO⁺ cells). In colorectal cancer-specific survival analyses, multivariable-adjusted hazard ratios (with 95% confidence intervals) were 0.32 (0.23–0.44; Ptrend <0.0001) for mature (vs. immature) desmoplastic reaction, 0.25 (0.16–0.39; Ptrend <0.0001) for absent (vs. marked) myxoid stroma, and 0.12 (0.05–0.28; Ptrend <0.0001) for absent (vs. marked) keloid-like collagen bundles. Conclusions: Immature desmoplastic reaction and myxoid stroma were associated with lower densities of tumor intraepithelial memory cytotoxic T cells and stromal M1-like macrophages, likely reflecting interactions between tumor, immune, and stromal cells in the colorectal tumor microenvironment

Smoking and incidence of colorectal cancer subclassified by tumor-associated macrophage infiltrates

Abstract Background: Biological evidence indicates that smoking can influence macrophage functions and polarization, thereby promoting tumor evolution. We hypothesized that the association of smoking with colorectal cancer incidence might differ by macrophage infiltrates. Methods: Using the Nurses’ Health Study and the Health Professionals Follow-up Study, we examined the association of smoking with incidence of colorectal cancer subclassified by macrophage counts. Multiplexed immunofluorescence (for CD68, CD86, IRF5, MAF, and MRC1 [CD206]) combined with digital image analysis and machine learning was used to identify overall, M1‐polarized, and M2‐polarized macrophages in tumor. We used inverse-probability–weighted multivariable Cox proportional hazards regression models to control for potential confounders and selection bias because of tissue data availability. All statistical tests were 2-sided. Results: During follow-up of 131 144 participants (3 648 370 person-years), we documented 3092 incident colorectal cancer cases, including 871 cases with available macrophage data. The association of pack-years smoked with colorectal cancer incidence differed by stromal macrophage densities (Pheterogeneity = 0.003). Compared with never smoking, multivariable-adjusted hazard ratios (95% confidence interval) for tumors with low macrophage densities were 1.32 (0.97 to 1.79) for 1–19 pack-years, 1.31 (0.92 to 1.85) for 20–39 pack-years, and 1.74 (1.26 to 2.41) for 40 or more pack-years (Ptrend = 0.004). In contrast, pack-years smoked was not statistically significantly associated with the incidence of tumors having intermediate or high macrophage densities (Ptrend > 0.009, with an α level of 0.005). No statistically significant differential association was found for colorectal cancer subclassified by M1‐like or M2‐like macrophages. Conclusions: The association of smoking with colorectal cancer incidence is stronger for tumors with lower stromal macrophage counts. Our findings suggest an interplay of smoking and macrophages in colorectal carcinogenesis