A Nomogram Based on Pretreatment Radiomics and Dosiomics Features for Predicting Overall Survival for Esophageal Squamous Cell Cancer: Multi-Institutional Study

PURPOSE/OBJECTIVE(S)

The current study aims to propose a nomogram-based 2- and 3-years survival prediction model for esophageal squamous cell carcinoma treated by definitive radiotherapy using pretreatment computed tomography (CT), positron emission tomography (FDG PET) radiomic features and dosiomics features in addition to the common clinical factors using multi-institution data.

MATERIALS/METHODS

Data of 112 patients from one institution and 28 patients from the other institution were retrospectively collected. Radiomics and dosiomics features were extracted using five segmentations on CT and PET images and dose distribution. The least absolute shrinkage and selection operator (LASSO) with logistic regression was used to select radiomics and dosiomics features by calculating the radiomics and dosiomics scores (Rad-score and Dos-score), respectively, in the training model. The predictive clinical factors, Rad-score, and Dos-score were identified to develop a nomogram model.

RESULTS

We extracted 15219 features from the radiomics and dosiomics analysis. By LASSO Cox regression analysis, 13 CT-based radiomics features, 11 PET-based radiomics features, and 19 dosiomics features were selected. Clinical factors of T-stage, N-stage, and clinical stage were selected as significant prognostic factors by univariate Cox regression analysis. A predictive nomogram for prognosis in was established using these factors. In the external validation cohort, the C-index of the combined model of CT-based radiomics, PET-based radiomics, and dosiomics features with clinical factors were 0.74, 0.82, and 0.92, respectively. Moreover, we divided the cohort into high-risk and low-risk groups using the median nomogram score. Significant differences in overall survival (OS) in the combine model of CT-based radiomics, PET-based radiomics, and dosiomics features with clinical factors were observed between the high-risk and low-risk groups (P = 0.019, P = 0.038, and 0.014, respectively).

CONCLUSION

The current study established and validated 2- and 3-year survival prediction models based on radiomics and dosiomics features with clinical factors. The prediction model with dosiomics analysis could better predict OS than CT- and PET-based radiomics analysis in esophageal cancer patients treated with radiotherapy.

Maternal high-fat diet promotes calcified atherosclerotic plaque formation in adult offspring by enhancing transformation of vascular smooth muscle cells to osteochondrocytic-like phenotype

Background and objective

Maternal high-fat diet (HFD) has been shown to modulate vascular function and remodeling in adult offspring. Atherosclerotic vascular calcification is closely associated with the onset of cardiovascular event. We therefore investigated the impact of maternal HFD on calcification of atherogenic plaques.

Methods and results

Eight-week-old female apo-E−/− mice (C57BL/6) were fed an HFD or a normal diet (ND) one week prior to mating, and the diet was continued throughout gestation and lactation. Offspring of both groups were fed a high-cholesterol diet (HCD) from 8 weeks of age. Ex vivo osteogenic activity of aortic root and aortic arch was analyzed using in vivo imaging system (IVIS) with OsteoSense 680. Sixteen-week-old male offspring of HFD-fed dams (O-HFD) showed a 1.4-fold increase in fluorescent intensity compared with those of ND-fed dams (O-ND) (p<0.05). Likewise, female O-HFD showed a significantly increased osteogenic activity in aortic arch (154%, p<0.05). Percentages of plaque area and oil red O-positive area were comparable between O-ND and O-HFD of both genders, suggesting that augmented osteogenic activity in O-HFD is not dependent on the plaque size. To investigate the underlying mechanism of augmented calcified plaque formation in O-HFD, vascular smooth muscle cells (VSMCs) of thoracic aorta form 8-week-old male offspring were primarily cultured and VSMCs calcification was induced by treatment with calcification media supplemented with phosphate (2.6 mM). Alizarin-red-positive area upon 10 days stimulation showed a 3.4-fold increase in VSMCs from O-HFD compared with that from O-ND (p<0.01). Consistently, western blotting analysis revealed that expression level of osteocalcin was significantly higher in O-HFD than O-ND, suggesting that osteochondrocytic transformation of VSMCs is augmented in O-HFD.

Conclusion

Our findings demonstrate that maternal HFD accelerates the development of atherogenic calcification independent of plaque size. In vitro transformation to osteochondrocytic-like cells is enhanced in VSMCs from offspring of HFD-fed dams. Inhibition of VSMCs skewing toward osteochondrocytic-like cells could be a potential therapeutic target for preventing the development of atherosclerotic vascular calcification.

Funding Acknowledgement

Type of funding source: None

Efficacy of cardiac rehabilitation with motion assistance from wearable cyborg hybrid assistive limb in patients with chronic heart failure: a randomized controlled trial

Background

Recent Cochrane Systematic Review suggested that the participation in cardiac rehabilitation is associated with approximately 20% lower cardiovascular mortality and morbidity. Exercise therapy is the key component of cardiac rehabilitation programs. In recent years, innovative technologies have been introduced into the field of rehabilitation, and a typical example is the wearable cyborg Hybrid Assistive Limb (HAL). The wearable cyborg HAL provides motion assistance based on detection of bioelectrical signals on the skin surface when muscle forces are generated. The lumbar-type HAL is expected to expand the therapeutic options for severe cardiac patients who have difficulty in performing usual cardiac rehabilitation programs, such as bicycle pedaling or walking.

Purpose

We aim to compare the efficacy of exercise therapy performed with motion assistance from a lumbar-type HAL versus conventional training (sit-to-stand exercise without HAL) in patients with chronic heart failure.

Methods

This clinical trial is a randomized, non-blinded, and controlled study. Twenty-eight heart failure patients (73.1±13.8 years) who have difficulty in walking at the usual walking speed of healthy subjects were randomly assigned to 2 groups (HAL group or control group) with a 1:1 allocation ratio and performed sit-to stand exercise either with HAL or without HAL for 5 to 30 minutes once a day, and 6 to 10 days during the study period. The brain natriuretic peptide (BNP), isometric knee extensor strength, standing ability (30-seconds chair-stand test: CS-30), short physical performance battery (SPPB) and 6-minute walking distance (6MWD) were measured before and after the completion of cardiac rehabilitation. Cardiac events such as death, re-hospitalization, myocardial infarction and worsening of angina pectoris and heart failure during 1 year after discharge were evaluated.

Results

There was no significant difference in the number of days of exercise therapy between the two groups. BNP, SPPB and 6MWD were improved in both groups. In the HAL group, the isometric knee extensor strength (0.29±0.11 vs 0.35±0.11 kgf/kg, p=0.003) significantly improved and CS-30 (5.5±5.1 vs 8.2±5.3, p=0.054) tended to improve. However, in the control group, either the isometric knee extensor strength (0.35±0.11 vs 0.36±0.14 kgf/kg, p=0.424) or CS-30 (6.0±4.3 vs 9.2±6.2, p=0.075) did not significantly change. HAL group showed significantly more improvement in the isometric knee extensor strength than control group (p=0.045). Cardiac events occurred in 20% in the HAL group and 43% in the control group.

Conclusion

The improvement in isometric knee extensor strength with the assistance from lumbar-type HAL suggests that exercise therapy using this device may be useful in chronic heart failure patients with flail or sarcopenia, a strong poor prognostic factor in these patients.

Funding Acknowledgement

Type of funding source: Public grant(s) – National budget only. Main funding source(s): This work was supported in part by a grant-in-aid for Scientific Research from the Ministry of Education, Science, and Culture of Japan (JSPS KAKENHI grant number JP17K09485) and funded by the ImPACT Program of the Council for Science, Technology and Innovation (Cabinet Office, Government of Japan) (grant number 2017-PM05-03-01).

Repeated social defeat exaggerates fibrin-rich clot formation in FeCl3-induced arterial thrombosis mouse model by enhancing NETs formation via modulation of neutrophil functional properties

Background and objective

Depression is an independent risk factor of cardiovascular disease (CVD). We have recently shown that repeated social defeat (RSD) precipitates depressive-like behaviors in apoE−/− mice and exaggerates atherosclerosis development by enhancing neutrophil extracellular traps (NETs) formation. Here, we investigated the impact of RSD on arterial thrombosis.

Methods and results

Eight-week-old male WT mice were exposed to RSD by housing with a larger CD-1 mouse in a shared home cage. They were subjected to vigorous physical contact daily for 10 consecutive days. Control mice were housed in the same gage without physical contact. After social interaction test to confirm depressive-like behaviors, defeated mice (19 of 31) and control mice (12 of 14) were underwent arterial injury at 10 wks of age. A filter paper saturated with 10% FeCl3 was applied on the adventitial surface of left carotid artery for 3 min and analyzed 3 hrs later. The volume of thrombi was comparable between the two groups. However, fibrinogen/fibrin-positive areas in immunofluorescent images significantly increased in defeated mice (27.8% vs. 48.8%, p<0.01). The number of Ly-6G-positive cells in thrombi was markedly higher in defeated mice (144/mm2 vs. 878/mm2, p<0.05). Further, Ly-6G-positive cells were almost accumulated at the inner surface of injured artery, which were co-localized with neutrophil elastase, Cit-H3, and CD41-positive staining. Treatment with DNase I completely diminished the exaggerated fibrin-rich clot formation in defeated mice to an extent similar to that in control mice (25.7% vs. 22.3%, p = ns), without affecting the volume of thrombi and accumulation of Ly-6G-positive cells. Given that platelet aggregations induced by ADP or collagen were comparable between the two groups, neutrophil functional properties primarily contribute to the exaggerated fibrin-rich clot formation in defeated mice. We then examined neutrophil subset and vulnerability to NETs formation. At 3 hrs after FeCl3 application, the numbers of immature neutrophils (Ly6Glo/+CXCR2-) were comparable between the two groups in both bone marrow (BM) and peripheral blood (PB). In contrast, the number of PB mature neutrophils (Ly6G+CXCR2+) was markedly higher in defeated mice than control mice (580±68 /μl vs. 1265±114, p<0.01). We next examined in vitro NETs formation upon PMA in BM mature neutrophils by FACS and nucleic acid staining. The percentage of double-positive cells (Cit-H3, MPO) was significantly higher in defeated mice (7.5% vs. 10.2%, p<0.05), as well as SYTOX green-positive cells expelling DNA fibers (8.1% vs. 11.8%, p<0.05).

Conclusions

Our findings demonstrate for the first time that repeated social defeat enhances fibrin-rich clot formation after arterial injury by enhancing NETs formation via modulation of neutrophil functional properties, suggesting that NETosis could be a new therapeutic target in depression-related CVD development.

Funding Acknowledgement

Type of funding source: None

Maternal high-fat diet promotes the expansion of abdominal aortic aneurysm in adult offspring by enhancing osteoclast-like macrophage differentiation through down-regulation of IRF8 expression

Background and objective

Maternal high-fat diet (HFD) has been shown to modulate vascular function and remodeling in adult offspring. Here, we investigated the impact of maternal HFD on abdominal aortic aneurysm (AAA) formation.

Methods and results

Eight-week-old female wild-type mice (C57BL/6) were fed a HFD or normal diet (ND) one week prior to mating, and the diet was continued throughout gestation and lactation. In eight-week-old male offspring, AAA was induced with the application of 0.5 M calcium chloride (CaCl2) on the infrarenal aorta. Offspring of HFD-fed dams (O-HFD) showed a significant increase in maximum outer diameter of AAA at 1, 4 and 8 weeks after surgery compared with offspring of ND-fed dams (O-ND). The lengths of outer circumference assessed by histological analysis were increased in O-HFD (p<0.05). Likewise, female O-HFD showed a greater length of outer circumference than female O-ND (p<0.05). While the number of F4/80-positive cells at 1 wk after surgery was comparable in the O-HFD and O-ND, the percentage of MMP-9/F4/80 double-positive cells was significantly increased in O-HFD. Consistently, fluorescent image of abdominal aorta taken by IVIS at 1 wk after surgery revealed a 2-fold increase in MMP activity. Intriguingly, F4/80-positive cells in O-HFD showed a 2.5-fold increase in co-staining with tartrate-resistant acid phosphate (TRAP), typical marker of osteoclast-like macrophages which abundantly secrete proteases than classically activated macrophages, while the percentage of TNF-α/F4/80 double-positive cells was comparable in the two groups. Pharmacological inhibition of osteoclastogenesis by zoledronic acid (ZA) (100μg/kg) completely abolished the exaggerated AAA development in O-HFD to an extent similar to that in O-ND, while AAA development in O-ND mice did not change after ZA treatment. Furthermore, in vitro TNF-α-induced osteoclast differentiation of bone marrow-derived macrophages (BMDMs) showed a significantly higher number of TRAP-positive cells in O-HFD, accompanied by a significant increase in osteoclast-related genes expression. Western blotting analysis revealed that the expression of NFATc1, master regulator of osteoclastogenesis, was significantly higher in O-HFD than that in O-ND, and immunofluorescent imaging showed that nuclear translocation of NFATc1 upon TNF-α stimulation was significantly enhanced in O-HFD. We further examined the expression of IFN regulatory factor 8 (IRF8) which suppresses osteoclastogenesis by inhibiting the function and expression of NFATc1. IRF8 mRNA and nuclear protein expression levels were significantly lower in O-HFD than those in O-ND.

Conclusion

Our findings demonstrate that maternal HFD accelerates CaCl2-induced AAA expansion, accompanied by the exaggerated accumulation of osteoclast-like macrophages and augmented activity of MMPs. Inhibition of macrophages skewing toward osteoclast-like cells could be a potential therapeutic target for preventing AAA development.

Funding Acknowledgement

Type of funding source: None

Repeated social defeat exaggerates CaCl2-induced abdominal aortic aneurysm expansion by eliminating periaortic fibrosis in tissue repair phase: possible involvement of specific subtypes of macrophages

Background and objective

Depression is an independent risk factor of cardiovascular disease (CVD) and significantly associated with the prevalence of abdominal aortic aneurysm (AAA). We have recently shown that repeated social defeat (RSD) precipitates depressive-like behaviors in apoE−/− mice and exaggerates atherosclerosis development by enhancing leukocyte activation. Here, we investigated the impact of RSD on AAA formation.

Methods and results

Eight-week-old male WT mice were exposed to RSD by housing with a larger CD-1 mouse in a shared home cage. They were subjected to vigorous physical contact daily for 10 consecutive days. Control mice were housed in the same gage without physical contact. After social interaction test to confirm depressive-like behaviors, defeated mice (28 of 48) and control mice (31 of 36) underwent application of 0.5 M calcium chloride (CaCl2) on the infrarenal aorta to induce AAA. At 1 week after application, maximum diameter and circumference of external elastic membrane were comparable between the two groups. The number of F-4/80, MMP-9, and TNF-α-positive cells in immunofluorescent images were also comparable. Further, in vitro bone marrow derived macrophages stimulation by LPS did not show any difference in mRNA expression levels of inflammatory cytokines, suggesting no discernable difference in acute inflammatory response between the two groups. In contrast, at 2 weeks after application, at the time point when MMP-9 and TNF-α-positive cells were scarcely observed, maximum diameter and circumference of external elastic membrane were significantly increased in defeated mice (0.72 mm vs. 0.90 mm, 1.59 mm vs. 2.00 mm, respectively, Control vs. Defeat, p<0.01). Intriguingly, periaortic fibrotic area in aneurysmal portion was markedly decreased in defeated mice (12.5×103 μm2 vs. 3.7×103 μm2, Control vs. Defeat, p<0.01). Consistently, accumulation of α-SMA-positive cells in adventitia of aneurysmal portion was much less in defeated mice than control mice (876 cells/mm2 vs. 319 cells/mm2, Control vs. Defeat, p<0.05), whereas those in tunica media of non-aneurysmal portion did not show any difference between the two groups. We next focused on the segregated nucleus-containing atypical monocyte (SatM), specific subtypes of monocytes/macrophages that are involved in fibrosis in injured tissues during the healing phase. We could observe SatM fraction in AAA tissue of control mice using flow cytometry. We also found that mRNA expression level of C/EBPβ, an essential regulator for SatM differentiation, was markedly decreased by 76% in BM cells of defeated mice compared with control mice (p<0.05).

Conclusions

Our findings demonstrate for the first time that RSD enhances AAA expansion by eliminating periaortic fibrosis in tissue repair phase, suggesting that the impaired resolution of acute inflammation after CaCl2 application contributes, at least in part, to the augmented expansion of AAA in defeated mice.

Funding Acknowledgement

Type of funding source: None

P732Maternal high-fat diet promotes the expansion of abdominal aortic aneurysm in adult offspring by enhancing osteoclast-like macrophage differentiation

Background and objective

Maternal high-fat diet (HFD) has been shown to modulate vascular function and remodeling in adult offspring. Here, we investigated the impact of maternal HFD on abdominal aortic aneurysm (AAA) formation.

Methods and results

Eight-week-old female wild-type mice (C57BL/6) were fed a HFD or normal diet (ND) one week prior to mating and received during pregnancy and lactation. In eight-week-old offspring of both genders, AAA was induced with the application of 0.5M calcium chloride (CaCl2) on the infrarenal aorta. Male offspring of HFD-fed dams (O-HFD) showed a significant increase in maximum outer diameter of AAA at 1, 4 and 8 weeks after surgery compared with offspring of ND-fed dams (O-ND) (P<0.05). The lengths of outer circumference assessed by histological analysis were increased in O-HFD (P<0.05). Likewise, female O-HFD showed a greater length of outer circumference than female O-ND (P<0.05). While the number of F4/80-positive cells at 1 wk after surgery was comparable between the male O-HFD and O-ND, the percentage of MMP-9/F4/80 double-positive cells was significantly increased in male O-HFD. Consistently, fluorescent image of abdominal aorta taken by IVIS at 1 wk after surgery revealed a 2-fold increase in MMP activity (P<0.01). Intriguingly, F4/80-positive cells in male O-HFD showed a 2.5-fold increase in co-staining with tartrate-resistant acid phosphate (TRAP), typical marker of osteoclast-like macrophages which abundantly secrete proteases than classically activated macrophages (M1), while the percentage of TNF-α/F4/80 double-positive cells was comparable between the 2 groups. Pharmacological inhibition of osteoclastogenesis by zoledronic acid (ZA) (100μg/kg) completely abolished the exaggerated AAA development in male O-HFD to a similar extent of that in male O-ND, while AAA development in male O-ND mice did not change even after ZA treatment. Furthermore, in vitro TNF-α-induced osteoclast differentiation of bone marrow-derived macrophages (BMDMs) showed a significantly higher number of TRAP-positive cells, accompanied by increased calcitonin receptor mRNA expression. Western blotting analysis showed that protein expression level of NFATc1, master regulator of osteoclastogenesis, was significantly higher in BMDM of O-HFD than O-ND.

Conclusion

Our findings demonstrate that maternal HFD accelerates CaCl2-induced AAA expansion, accompanied by the exaggerated accumulation of osteoclast-like macrophages and augmented activity of MMPs. Inhibition of macrophages skewing toward osteoclast-like cells could be a potential therapeutic target for preventing AAA development.

P740Repeated social defeat exaggerates fibrin-rich clot formation in FeCl3-induced arterial thrombosis mice model by enhancing NETs formation

Background and objective

Depression is an independent risk factor of cardiovascular disease (CVD). We have recently shown that repeated social defeat (RSD) precipitates depressive-like behaviorsin apoE−/− mice and exaggerates atherosclerosis development by enhancing neutrophil extracellular traps (NETs) formation (BBRC 2018; 500:490). Here, we investigated the impact of RSD on arterial thrombosis.

Methods and results

Eight-week-old male WT mice were exposed to RSDby housing with a larger CD-1 mouse in a shared home cage. They were subjected to vigorous physical contact daily for 10 consecutive days. Control mice were housed in the same gage without physical contact. After social interaction testto confirm depressive-like behaviors, defeated mice (19 of 31) and control mice (12 of 14) were underwent arterial injury at 10 wks of age. A filter paper saturated with 10% FeCl3was applied on the adventitial surface of left carotid artery for 3 min and analyzed 3 hrs later. The volume of thrombi calculated by summing8–15 frozen cross-sectional images, each separated by 200 μm, was comparable between the 2 groups. However, fibrinogen/fibrin-positive areas in immunofluorescent images were significantly increased in defeated mice (27.8% vs. 48.8%, Control vs. Defeat, P<0.01).The numberof Ly-6G-positive cells in thrombi was markedly higher in defeated mice (144/mm2 vs. 878/mm2, Control vs. Defeat, P<0.05). Further, Ly-6G-positive cells were almost accumulated at the inner surface of injured artery, which were co-localized with neutrophil elastase, Cit-H3, and CD41-positive staining. Treatment with DNase Icompletely diminished the exaggerated fibrin-rich clot formation in defeated miceto a similar extent of control mice (25.7% vs. 22.3%, Control vs. Defeat, P= NS), while the volume of thrombi and number of Ly-6G-positive cells in thrombi were comparable between the 2 groups even afterDNase I treatment. Platelet aggregations induced by ADP or collagen were comparable between the 2 groups, suggesting that NETs formation primarily contributes to the exaggerated fibrin-rich clot formation in defeated mice.

Conclusions

Our findings demonstrate for the first time that repeated social defeat enhances fibrin-rich clot formation after arterial injury by enhancing NETs formation, suggesting that NETosis could be a new therapeutic target in depression-related CVD development.

5220Maternal high-fat diet exaggerates the development of diet-induced insulin resistance in adult offspring by enhancing pyroptosis through augmented gasdermin D-mediated pore formation

Background

Maternal high-fat diet (HFD) has been shown to promote the development of insulin resistance (IR) in adult offspring; however, the underlying mechanisms remain unclear.

Approach and results

Eight-week-old female wild-type mice (C57BL/6) were fed a HFD or normal diet (ND) one week prior to mating, and received during pregnancy and lactation. Eight-week-old male offspring of both groups were fed a HFD for 8 weeks. Offspring of HFD-fed dams (O-HFD) showed significantly enhanced IR compared with offspring of ND-fed dams (O-ND). There was no difference in body weight, epidydimal white adipose tissue (eWAT) weight, and cumulative caloric intake between the 2 groups. However, eWAT adipocyte size was significantly increased in O-HFD, accompanied by the abundant crown-like structures. Flow cytometric analysis revealed an increased percentage of M1, but not M2, macrophages. Serum and eWAT concentrations of IL-1β, but not TNF-α, were significantly higher in O-HFD than O-ND (3.7-fold and 2.0-fold, respectively, P<0.05). Treatment with NLRP3 inflammasome inhibitor MCC950 completely abrogated the enhanced IR in O-HFD to a similar extent of that in O-ND, although IR was modestly, but not significantly, ameliorated in O-ND even after MCC950 treatment. Consistent with in vivo findings, in vitro polarization of bone marrow-derived macrophages (BMDMs) did not show any difference in TNF-α mRNA expression after conventional stimulation. In contrast, palmitate acid (PA)-mediated metabolic activation of BMDMs following LPS priming showed a significantly higher concentration of IL-1β in culture supernatants from O-HFD (45%, P<0.05). However, protein expression levels of NLRP-3, ASC, and procaspase-1 after LPS priming were equivalent between the 2 groups. Consistently, intracellular flow cytometric analysis of caspase-1 activity after PA activation did not show any difference, which was compatible with the finding that ex vivo caspase-1 activity of eWAT assessed by fluorescent image of IVIS revealed no difference between the 2 groups. To further examine the mechanism of augmented IL-1β release in BMDM of O-HFD, we examined the cleavage of caspase substrate gasdermin D (GSDMD) and subsequent pore formation. Protein and gene expression levels of GSDM-D after LPS priming were significantly higher in O-HFD (50% and 381%, respectively, P<0.05). At 2 hrs after PA stimulation following LPS priming, cleaved GSDM-D was significantly increased in O-HFD (80%, P<0.01). Consistently, percentage of pore formation assessed by ethidium bromide staining was significantly higher in O-HFD (60%, P<0.05), while LDH release could not be observed.

Conclusions

Our findings demonstrate that maternal HFD exaggerates diet-induced insulin resistance in adult offspring by enhancing pyroptosis through augmented GSDM-D-mediated pore formation.

Temporal pattern recognition with delayed feedback spin-torque nano-oscillators

The recent demonstration of neuromorphic computing with spin-torque nano-oscillators has opened a path to energy efficient data processing. The success of this demonstration hinged on the intrinsic short-term memory of the oscillators. In this study, we extend the memory of the spin-torque nano-oscillators through time-delayed feedback. We leverage this extrinsic memory to increase the efficiency of solving pattern recognition tasks that require memory to discriminate different inputs. The large tunability of these non-linear oscillators allows us to control and optimize the delayed feedback memory using different operating conditions of applied current and magnetic field.

Vector network analyzer ferromagnetic resonance spectrometer with field differential detection

This work presents a vector network analyzer ferromagnetic resonance (VNA-FMR) spectrometer with field differential detection. This technique differentiates the S-parameter by applying a small binary modulation field in addition to the DC bias field to the sample. By setting the modulation frequency sufficiently high, slow sensitivity fluctuations of the VNA, i.e., low-frequency components of the trace noise, which limit the signal-to-noise ratio of the conventional VNA-FMR spectrometer, can be effectively removed, resulting in a very clean FMR signal. This paper presents the details of the hardware implementation and measurement sequence as well as the data processing and analysis algorithms tailored for the FMR spectrum obtained with this technique. Because the VNA measures a complex S-parameter, it is possible to estimate the Gilbert damping parameter from the slope of the phase variation of the S-parameter with respect to the bias field. We show that this algorithm is more robust against noise than the conventional algorithm based on the linewidth.

Neuromorphic Computing through Time-Multiplexing with a Spin-Torque Nano-Oscillator

Fabricating powerful neuromorphic chips the size of a thumb requires miniaturizing their basic units: synapses and neurons. The challenge for neurons is to scale them down to submicrometer diameters while maintaining the properties that allow for reliable information processing: high signal to noise ratio, endurance, stability, reproducibility. In this work, we show that compact spin-torque nano-oscillators can naturally implement such neurons, and quantify their ability to realize an actual cognitive task. In particular, we show that they can naturally implement reservoir computing with high performance and detail the recipes for this capability.

Identification and functional activity of a staphylocoagulase type XI variant originating from staphylococcal food poisoning isolates

Staphylocoagulase, an extracellular protein secreted by Staphylococcus aureus, has been used as an epidemiological marker. At least 12 serotypes and 24 genotypes subdivided on the basis of nucleotide sequence have been reported to date. In this study, we identified a novel staphylocoagulase nucleotide sequence, coa310, from staphylococcal food poisoning isolates that had the ability to coagulate plasma, but could not be typed using the conventional method. The protein encoded by coa310 contained the six fundamental conserved domains of staphylocoagulase. The full-length nucleotide sequence of coa310 shared the highest similarity (77·5%) with that of staphylocoagulase-type (SCT) XIa. The sequence of the D1 region, which would be responsible for the determination of SCT, shared the highest similarity (91·8%) with that of SCT XIa. These results suggest that coa310 is a novel variant of SCT XI. Moreover, we demonstrated that coa310 encodes a functioning coagulase, by confirming the coagulating activity of the recombinant protein expressed from coa310. This is the first study to directly demonstrate that Coa310, a putative SCT XI, has coagulating activity. These findings may be useful for the improvement of the staphylocoagulase-typing method, including serotyping and genotyping.

SIGNIFICANCE AND IMPACT OF THE STUDY

This is the first study to identify a novel variant of staphylocoagulase type XI based on its nucleotide sequence and to demonstrate coagulating activity in the variant using a recombinant protein. Elucidation of the variety of staphylocoagulases will provide suggestions for further improvement of the staphylocoagulase-typing method and contribute to our understanding of the epidemiologic characterization of Staphylococcus aureus.

Dangerous Mixture of Household Detergents in an Old-style Toilet: a Case Report with Simulation Experiments of the Working Environment and Warning of Potential Hazard Relevant to the General Environment

A housewife cleaned toilet porcelain connected directly to a sewage storage tank with a mixture of cleaning agents; sodium hypochlorite (NaOCl) and hydrochloric acid (HCl) solutions. She complained of insomnia on the night after cleaning and suffered from severe metabolic acidosis with extremely low blood pH, PCO2 and bicarbonate values. She recovered from the acidosis after bicarbonate transfusion, plasmapheresis and plasma exchange. Permanent blindness ensued, however, from the third day after the event. These clinical symptoms suggested that the toxic substances responsible were chloramine and methyl chloride. Their generation was confirmed by in-vitro experiments, mixing NaOCl, HCl and pooled urine from normal people. In the simulation, the methyl chloride level far exceeded (100 000 ppm) the maximal allowable concentration recommended (ca 400 ppm) by the American Conference of Governmental Industrial Hygienists (ACGIH). Chloramine's toxic actions were confirmed using purified enzyme assay, and the inhibition of carbonic anhydrase and aldehyde dehydrogenase and the enhancement of superoxide dismutase activity were confirmed in neutral pH. The patient's clinical symptoms suggested that insomnia and permanent blindness seemed to be partly ascribable to chronic repetitive exposure to methyl chloride; catching a cold, drug intake and alcohol intake, in addition, precipitated the patient's visual loss. The possibility of this kind of intoxication with such a mixture of agents may lie latent in any situation where sewage or garbage are exposed to the open air.

Fish collagen is an important panallergen in the Japanese population

Collagen was identified as a fish allergen in early 2000s. Although its allergenic potential has been suggested to be low, risks associated with collagen as a fish allergen have not been evaluated to a greater extent. In this study, we aimed to clarify the importance of collagen as a fish allergen. Our results showed that 50% of Japanese patients with fish allergy had immunoglobulin E (IgE) against mackerel collagen, whereas 44% had IgE against mackerel parvalbumin. IgE inhibition assay revealed high cross-reactivity of mackerel collagen to 22 fish species (inhibition rates: 87-98%). Furthermore, a recently developed allergy test demonstrated that collagen triggered IgE cross-linking on mast cells. These data indicate that fish collagen is an important and very common panallergen in fish consumed in Japan. The high rate of individuals' collagen allergy may be attributable to the traditional Japanese custom of raw fish consumption.

Spin-torque resonant expulsion of the vortex core for an efficient radiofrequency detection scheme

It has been proposed that high-frequency detectors based on the so-called spin-torque diode effect in spin transfer oscillators could eventually replace conventional Schottky diodes due to their nanoscale size, frequency tunability and large output sensitivity. Although a promising candidate for information and communications technology applications, the output voltage generated from this effect has still to be improved and, more pertinently, reduces drastically with decreasing radiofrequency (RF) current. Here we present a scheme for a new type of spintronics-based high-frequency detector based on the expulsion of the vortex core in a magnetic tunnel junction (MTJ). The resonant expulsion of the core leads to a large and sharp change in resistance associated with the difference in magnetoresistance between the vortex ground state and the final C-state configuration. Interestingly, this reversible effect is independent of the incoming RF current amplitude, offering a fast real-time RF threshold detector.

Effect of fermented milk containing Lactobacillus casei strain Shirota on constipation-related symptoms and haemorrhoids in women during puerperium

Constipation and haemorrhoids are common complaints after childbirth. The objective of this pilot study was to evaluate impact of fermented milk containing Lactobacillus casei strain Shirota (LcS) on stool consistency and frequency, constipation-related symptoms and quality of life, and incidence of haemorrhoids in women during puerperium. Forty women who had natural childbirth were randomised to group consuming either one bottle/day of fermented milk containing at least 6.5×109 cfu of LcS, or placebo, for 6 weeks after childbirth. Subjects filled in a diary on their bowel habits including number of bowel movement, stool consistency and incidence of haemorrhoids, and answered questionnaires on constipation-related symptoms (PAC-SYM) and quality of life (PAC-QOL) during the study period. The probiotic group showed the better scores on overall PAC-SYM (P=0.013), PAC-SYM subscales of abdominal symptoms (P=0.043) and rectal symptoms (P=0.031), and PAC-QOL satisfaction subscale (P=0.037) in comparison with the placebo group. In the probiotic group, two to four subjects experienced haemorrhoids during the first 3 weeks of treatment. The number decreased in week 4 and no one had haemorrhoids on most days in week 5-6. In the placebo group, on average four subjects had haemorrhoids from the beginning, and no obvious change was observed until week 6. No statistically significant effect was observed on stool consistency and frequency. The study products did not cause any adverse event in the subjects. Results of this study indicate that continuous consumption of fermented milk containing LcS might alleviate constipation-related symptoms, provide satisfactory bowel habit and result in earlier recovery from haemorrhoids in women during puerperium. Nonetheless, there are several limitations in interpretation of the results attributed to the study design, including lack of baseline data. Further study is required in order to confirm the efficacy.