Anthropogenic combustion iron as a complex climate forcer

Atmospheric iron affects the global carbon cycle by modulating ocean biogeochemistry through the deposition of soluble iron to the ocean. Iron emitted by anthropogenic (fossil fuel) combustion is a source of soluble iron that is currently considered less important than other soluble iron sources, such as mineral dust and biomass burning. Here we show that the atmospheric burden of anthropogenic combustion iron is 8 times greater than previous estimates by incorporating recent measurements of anthropogenic magnetite into a global aerosol model. This new estimation increases the total deposition flux of soluble iron to southern oceans (30-90 °S) by 52%, with a larger contribution of anthropogenic combustion iron than dust and biomass burning sources. The direct radiative forcing of anthropogenic magnetite is estimated to be 0.021 W m^-2 globally and 0.22 W m^-2 over East Asia. Our results demonstrate that anthropogenic combustion iron is a larger and more complex climate forcer than previously thought, and therefore plays a key role in the Earth system.

Anthropogenic combustion iron as a complex climate forcer

Atmospheric iron affects the global carbon cycle by modulating ocean biogeochemistry through the deposition of soluble iron to the ocean. Iron emitted by anthropogenic (fossil fuel) combustion is a source of soluble iron that is currently considered less important than other soluble iron sources, such as mineral dust and biomass burning. Here we show that the atmospheric burden of anthropogenic combustion iron is 8 times greater than previous estimates by incorporating recent measurements of anthropogenic magnetite into a global aerosol model. This new estimation increases the total deposition flux of soluble iron to southern oceans (30–90 °S) by 52%, with a larger contribution of anthropogenic combustion iron than dust and biomass burning sources. The direct radiative forcing of anthropogenic magnetite is estimated to be 0.021 W m⁻² globally and 0.22 W m⁻² over East Asia. Our results demonstrate that anthropogenic combustion iron is a larger and more complex climate forcer than previously thought, and therefore plays a key role in the Earth system.

As a source of soluble iron, anthropogenic combustion iron is considered less important than natural sources. Here, the authors combine new measurements with a global aerosol model and show the atmospheric burden of anthropogenic combustion iron to be 8 times greater than previous estimates.

Abstract P1-05-05: Hyperthermia regulates transporter expression via ROS production and enhances the cytotoxicity of doxorubicin

Introduction: Hyperthermia (HT) is a non-invasive cancer therapy. Treatment temperature between 41°C to 44°C has no cytotoxic damage in normal cells, however shows cytotoxicity in cancer cells because of the underdeveloped vascular system. HT often used with other cancer therapy such as radiation therapy and chemotherapy. However mechanism of synergistic effect using these therapies remains unclear. Compared to 37°C, 42°C is mild heat stress for cells, thus superoxide anion is released from tissue. Superoxide anion is produced by mitochondrial electron transport chain. Reactive oxygen species (ROS), produced by mild heat stress, can be released from mitochondria. We have previously reported that ATP-binding cassette sub-family G member 2 (ABCG2) expression was suppressed by increasing mitochondrial ROS, and induction of the cancer specific porphyrin accumulation. ABCG2 is a transporter of doxorubicin (DOX), therefore we hypothesized that synergistic effect of HT and chemotherapy would be induced by down-regulation of ABCG2 expression via intracellular ROS increase. In this study, we investigated if cytotoxic effect of breast cancer cell using DOX can be enhance by HT via intracellular ROS increase.

Materials and methods: The murine breast cancer cell line, 4T1E was incubated at 37°C or 42°C for 1h. Intracellular ROS generation after HT treatment was detected by electron spin resonance (ESR). Twenty four hours after HT treatment, cells were incubated in medium containing 0, 0.1 and 1 μM DOX for 24 h. Cell viability was measured using the Cell Counting Kit 8, a water-soluble tetrazolium-8 based colorimetric assay. ABCG2 expression in whole cells was analyzed by Western blotting.

Results and discussion: ESR signal peak with HT treatment became high as compared to without HT treatment, indicating intracellular ROS level was increased by HT treatment. Cell viability and ABCG2 expression were decreased by DOX exposure and by HT treatment. The enhancement of HT treatment effect by DOX is considered to be result of down-regulation of ABCG2 expression by ROS. When cells were exposed to DOX with 5-aminolevulinic acid (ALA), cell viability reduced further. Since it is known that porphyrin is introduced by ALA and is transported by ABCG2, we speculate that ALA worked as a competitive inhibitor of DOX excretion transporter to enhance cell death. ESR signal peak in ALA treatment cells was higher than that in non-ALA treatment cells. Significant increase in cellular damage by HT treatment was shown by adding ALA, but not without ALA. Moreover, cell death induced by HT and ALA treatment was suppressed by adding N-acetylcysteine (NAC), which is an antioxidant. These results suggest that cellular damage of HT treatment is due to ROS production induced by ALA.

Conclusion: HT treatment involved intracellular ROS production and down-regulated the expression of ABCG2 protein. HT treatment also enhanced the cell damage by DOX. Cell death by DOX was enhanced by combination with HT and ALA treatment, possibly via intracellular ROS generation, and was suppressed by additing antioxidant.

Citation Format: Terasaki A, Kurokawa H, Terasaki M, Ito H, Matsui H, Ichioka E, Tsushima Y, Manaka-Iguchi A, Bando H, Hara H. Hyperthermia regulates transporter expression via ROS production and enhances the cytotoxicity of doxorubicin [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P1-05-05.

Association between hospital volume and in-hospital mortality following radiofrequency ablation for hepatocellular carcinoma

Background

Radiofrequency ablation (RFA) is a minimally invasive treatment for hepatocellular carcinoma (HCC). There is increasing evidence of an association between increasing hospital volume and lower postoperative mortality for many surgical procedures, but this is difficult to establish with minimally invasive treatments, where postoperative mortality is low. The aim of this study was to investigate the relationship between hospital volume and in-hospital mortality following RFA using a Japanese nationwide database.

Methods

Data from the Diagnostic Procedure Combination database were analysed from 1 July 2010 to 31 March 2012. Multivariable logistic regression was used to analyse the relationship between hospital volume and in-hospital mortality following RFA, with adjustment for patient background.

Results

Some 36 675 patients with HCC were identified in the database. The overall in-hospital mortality rate from RFA was 0·31 per cent. In-hospital mortality was significantly higher in low-volume than high-volume hospitals (odds ratio 2·57, 95 per cent c.i. 1·61 to 4·09; P < 0·001). Higher in-hospital mortality was significantly associated with older age and a higher Charlson Co-morbidity Index score.

Conclusion

RFA for HCC was associated with acceptably low mortality in Japan, but in-hospital mortality following RFA was affected by hospital procedural volume.

Epidural analgesia is infrequently used in patients with acute pancreatitis : a retrospective cohort study

BACKGROUNDS AND AIMS

Epidural analgesia is an option for pain control in patients with acute pancreatitis. The aim of this study is to describe characteristics, morbidity and mortality of patients with acute pancreatitis treated with epidural analgesia.

PATIENTS AND METHODS

Data was extracted from a national inpatient database in Japan on patients hospitalized with acute pancreatitis between July 2010 and March 2013. A total of 44,146 patients discharged from acute care hospitals were included in this retrospective cohort study. The patient background, timing and duration of epidural analgesia, complications (epidural hematoma or abscess), surgery (for cholelithiasis / cholecystitis or complications) and mortality were verified.

RESULTS

Epidural analgesia was used in 307 patients (0.70 %). The mean age was 64.0 years (standard deviation, 15.4 years) and 116 (37.8%) of the patients were female. The median duration of epidural analgesia was four days (interquartile range, 3-5 days). No patient underwent surgery for epidural hematoma or abscess. Six (2.0%) patients died during hospitalization. Most likely causes of death were pulmonary embolism, multiple organ failure, sepsis, and methicillin-resistant staphylococcus aureus enterocolitis. The responsible physician for 250 of the patients (81.4%) was a gastroenterological surgeon. Epidural analgesia was started on the day of surgery in 278 (90.6%) patients.

CONCLUSION

Epidural analgesia is rarely used in patients with acute pancreatitis. None of the patients included in the study required surgery for epidural hematoma or abscess. Further research to evaluate the efficacy and safety of epidural analgesia in patients with acute pancreatitis is warranted.

Effectiveness of early administration of tranexamic acid in patients with severe trauma

BACKGROUND

A reduction in mortality with the early use of tranexamic acid has been demonstrated in severely injured patients who are bleeding. However, the modest treatment effect with no reduction in blood transfusion has raised concerns. The aim of the present study was to estimate the effectiveness of regular use of tranexamic acid in severely injured patients.

METHODS

This multicentre observational study used retrospectively collected data from consecutive injured patients (Injury Severity Score at least 16) treated in 15 Japanese academic institutions in 2012. A propensity score-matched analysis compared patients who did or did not receive tranexamic acid administration within 3 h of injury. Study outcomes included 28-day all-cause and cause-specific mortality, and need for blood transfusion.

RESULTS

Of 796 eligible subjects, 281 were treated with tranexamic acid. Propensity score matching selected a total of 500 matched subjects (250 in each group). Tranexamic acid administration was associated with lower 28-day mortality (10·0 versus 18·4 per cent; difference -8·4 (95 per cent c.i. -14·5 to -2·3) per cent) and lower 28-day mortality from primary brain injury (6·0 versus 13·2 per cent; difference -7·2 (-12·3 to -2·1) per cent). However, there was no significant difference between groups in the need for blood transfusion (33·2 versus 34·8 per cent; difference -1·6 (-9·9 to 6·7) per cent).

CONCLUSION

Early tranexamic acid use was associated with reduced mortality in severely injured patients, in particular those with a primary brain injury.

A novel LSD1 inhibitor NCD38 ameliorates MDS-related leukemia with complex karyotype by attenuating leukemia programs via activating super-enhancers

Lysine-specific demethylase 1 (LSD1) regulates gene expression by affecting histone modifications and is a promising target for acute myeloid leukemia (AML) with specific genetic abnormalities. Novel LSD1 inhibitors, NCD25 and NCD38, inhibited growth of MLL-AF9 leukemia as well as erythroleukemia, megakaryoblastic leukemia and myelodysplastic syndromes (MDSs) overt leukemia cells in the concentration range that normal hematopoiesis was spared. NCD25 and NCD38 invoked the myeloid development programs, hindered the MDS and AML oncogenic programs, and commonly upregulated 62 genes in several leukemia cells. NCD38 elevated H3K27ac level on enhancers of these LSD1 signature genes and newly activated ~500 super-enhancers. Upregulated genes with super-enhancer activation in erythroleukemia cells were enriched in leukocyte differentiation. Eleven genes including GFI1 and ERG, but not CEBPA, were identified as the LSD1 signature with super-enhancer activation. Super-enhancers of these genes were activated prior to induction of the transcripts and myeloid differentiation. Depletion of GFI1 attenuated myeloid differentiation by NCD38. Finally, a single administration of NCD38 causes the in vivo eradication of primary MDS-related leukemia cells with a complex karyotype. Together, NCD38 derepresses super-enhancers of hematopoietic regulators that are silenced abnormally by LSD1, attenuates leukemogenic programs and consequently exerts anti-leukemic effect against MDS-related leukemia with adverse outcome.

Developing a Practical Method for Validation of Computerized Systems Integrated With Smart and/or Wearable Devices for Regulatory Compliance of Clinical Trials

BACKGROUND

The use of smart and/or wearable devices for collection of electronic data in clinical trials has recently become a strong tool with which to collect patients' data in a timely manner. Electronic collection of patient data will necessitate comprehensive data analysis involving huge-scale datasets in the future. However, it is still unclear how to validate and qualify computerized systems used to collect and/or manage electronic clinical data when smart and/or wearable devices are involved.

METHODS

We (a special interest group of Good Automated Manufacturing Practice Japan Forum [GAMP Japan]) investigated and designed a data-flow model for a clinical data management system involving smart and/or wearable devices, and suggested an approach for the validation of such a computerized system. The appropriateness of applying GAMP5 to the validation of a clinical data management system involving smart and/or wearable devices was also reviewed.

RESULTS

A regulated company should have policies and standard procedures for validating computerized systems in clinical systems. When a sponsor engages a contract research organization (CRO) for clinical data management, the sponsor should assess the CRO to confirm their capabilities. The sponsor also needs to check whether the CRO assesses device manufacturers as sub-suppliers. When the CRO intends to conduct sub-supplier assessment with a device manufacturer, a risk-based approach can be taken.

CONCLUSIONS

We believe our method of system validation will be applicable to and will facilitate various clinical trials that involve smart and/or wearable devices.