First Dark Matter Search with Nuclear Recoils from the XENONnT Experiment

We report on the first search for nuclear recoils from dark matter in the form of weakly interacting massive particles (WIMPs) with the XENONnT experiment, which is based on a two-phase time projection chamber with a sensitive liquid xenon mass of 5.9 ton. During the (1.09±0.03)  ton yr exposure used for this search, the intrinsic ^{85}Kr and ^{222}Rn concentrations in the liquid target are reduced to unprecedentedly low levels, giving an electronic recoil background rate of (15.8±1.3)  events/ton yr keV in the region of interest. A blind analysis of nuclear recoil events with energies between 3.3 and 60.5 keV finds no significant excess. This leads to a minimum upper limit on the spin-independent WIMP-nucleon cross section of 2.58×10^{-47}  cm^{2} for a WIMP mass of 28  GeV/c^{2} at 90% confidence level. Limits for spin-dependent interactions are also provided. Both the limit and the sensitivity for the full range of WIMP masses analyzed here improve on previous results obtained with the XENON1T experiment for the same exposure.

Searching for Heavy Dark Matter near the Planck Mass with XENON1T

Multiple viable theoretical models predict heavy dark matter particles with a mass close to the Planck mass, a range relatively unexplored by current experimental measurements. We use 219.4 days of data collected with the XENON1T experiment to conduct a blind search for signals from multiply interacting massive particles (MIMPs). Their unique track signature allows a targeted analysis with only 0.05 expected background events from muons. Following unblinding, we observe no signal candidate events. This Letter places strong constraints on spin-independent interactions of dark matter particles with a mass between 1×10^{12} and 2×10^{17}  GeV/c^{2}. In addition, we present the first exclusion limits on spin-dependent MIMP-neutron and MIMP-proton cross sections for dark matter particles with masses close to the Planck scale.

Search for New Physics in Electronic Recoil Data from XENONnT

We report on a blinded analysis of low-energy electronic recoil data from the first science run of the XENONnT dark matter experiment. Novel subsystems and the increased 5.9 ton liquid xenon target reduced the background in the (1, 30) keV search region to (15.8±1.3)  events/(ton×year×keV), the lowest ever achieved in a dark matter detector and ∼5 times lower than in XENON1T. With an exposure of 1.16 ton-years, we observe no excess above background and set stringent new limits on solar axions, an enhanced neutrino magnetic moment, and bosonic dark matter.

Hospital-acquired disability in older heart failure patients decreases independence and increases difficulties in activities of daily living

AIMS

The aim of this study was to clarify whether worsening of independence in activities of daily living (ADL) and also difficulties in ADL are triggered by hospitalization in older patients with heart failure (HF) and whether difficulties in ADL can predict readmission for HF regardless of independence in ADL in these patients.

METHODS AND RESULTS

We enrolled 241 HF patients in the present multi-institutional, prospective, observational study. The patients were divided according to age into the non-older patient group (<75 years, n = 137) and the older patient group (≥75 years, n = 104). The Katz index and the Performance Measure for Activities of Daily Living-8 (PMADL-8) were used to evaluate independence and difficulties in ADL, respectively. The endpoint of this study was rehospitalization for HF. Independence as indicated by the Katz index at discharge was significantly lower than that before admission only in the older patient group, and the value of the PMADL-8 at discharge was significantly higher than that before admission (P < 0.001). In all patients, after adjusting for the Katz index and other variables, PMADL-8 score was a significant predictor of rehospitalization for HF (hazard ratio 1.50; 95% confidence interval 1.07 to 2.13; P = 0.021).

CONCLUSIONS

Worsening of both independence and difficulties in ADL was triggered by hospitalization in older HF patients, and difficulties in ADL were relevant factors for risk of rehospitalization regardless of independence in ADL. These findings indicate the importance of preventing not only decreased independence but also increased difficulties in ADL during and after hospitalization.

Material radiopurity control in the XENONnT experiment

The selection of low-radioactive construction materials is of the utmost importance for rare-event searches and thus critical to the XENONnT experiment. Results of an extensive radioassay program are reported, in which material samples have been screened with gamma-ray spectroscopy, mass spectrometry, and \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$^{222}$$\end{document}222Rn emanation measurements. Furthermore, the cleanliness procedures applied to remove or mitigate surface contamination of detector materials are described. Screening results, used as inputs for a XENONnT Monte Carlo simulation, predict a reduction of materials background (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\sim $$\end{document}∼17%) with respect to its predecessor XENON1T. Through radon emanation measurements, the expected \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$^{222}$$\end{document}222Rn activity concentration in XENONnT is determined to be 4.2 (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$^{+0.5}_{-0.7}$$\end{document}-0.7+0.5) \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\upmu $$\end{document}μBq/kg, a factor three lower with respect to XENON1T. This radon concentration will be further suppressed by means of the novel radon distillation system.

Prognostic significance of right ventricular function during exercise in asymptomatic/minimally symptomatic patients with nonobstructive hypertrophic cardiomyopathy

BACKGROUND

The risk stratification of hypertrophic cardiomyopathy (HCM) without left ventricular outflow tract (LVOT) obstruction and the utility of exercise stress echocardiography (ESE) remains unclear. We investigated the value of right ventricular (RV) function and RV-pulmonary artery (PA) coupling during exercise in asymptomatic/minimally symptomatic patients with nonobstructive HCM (nHCM).

METHOD AND RESULTS

This retrospective study evaluated 74 HCM patients (age 63 ± 13 years, 65% men) without LVOT obstruction (≥30 mmHg) who underwent​ ESE. Eight patients (11%) suffered from HCM-related cardiac events during a median 2.5 years follow-up. During exercise, tricuspid annular plane systolic excursion (Ex-TAPSE) and Ex-TAPSE/systolic pulmonary artery pressure [SPAP] ratio were more impaired in patients with than in those without events (22 ± 4 vs 26 ± 4 mm, P = .005; and 0.45 [0.41, 0.47] vs 0.56 [0.47, 0.82] mm/mmHg, P = .002). In Cox regression analysis, Ex-TAPSE (HR: 1.397, P = .002) and the Ex-TAPSE/SPAP ratio (HR: 2.737, P = .006) were associated with cardiac events. In Kaplan-Meier analysis, patients with a low Ex-TAPSE (<24 mm) and Ex-TAPSE/SPAP ratio (<0.50 mm/mmHg) had a higher incidence of adverse outcomes than those with high Ex-TAPSE (Log rank, P < .001 and =.001, respectively).

CONCLUSIONS

A low Ex-TAPSE and Ex-TAPSE/SPAP ratio were associated with adverse outcomes in nHCM. Evaluation of RV functional performance during exercise may play a crucial role in the risk stratification of nHCM.

Search for Coherent Elastic Scattering of Solar ^{8}B Neutrinos in the XENON1T Dark Matter Experiment

We report on a search for nuclear recoil signals from solar ^{8}B neutrinos elastically scattering off xenon nuclei in XENON1T data, lowering the energy threshold from 2.6 to 1.6  keV. We develop a variety of novel techniques to limit the resulting increase in backgrounds near the threshold. No significant ^{8}B neutrinolike excess is found in an exposure of 0.6  t×y. For the first time, we use the nondetection of solar neutrinos to constrain the light yield from 1-2 keV nuclear recoils in liquid xenon, as well as nonstandard neutrino-quark interactions. Finally, we improve upon world-leading constraints on dark matter-nucleus interactions for dark matter masses between 3 and 11  GeV c^{-2} by as much as an order of magnitude.

Prognostic relevance of exercise pulmonary hypertension for new-onset atrial fibrillation in primary mitral regurgitation

Background/Introduction

New-onset of atrial fibrillation (AF) portends poor prognosis in patients with primary mitral regurgitation (MR). However less is known about prognostic indicator for new-onset AF.

Purpose

The purpose of this study was to identify the prognostic relevance of exercise pulmonary hypertension for the new-onset AF in patients with primary MR.

Methods

Total of 114 consecutive patients with primary MR who underwent symptom-limited exercise echocardiography using supine-cycle ergometer were followed for new-onset AF over mean follow-up time of 3.6±2.6 years. Those with prevalent AF and pulmonary hypertension (estimated systolic pulmonary artery pressure ≥50mmHg) prior to exercise echocardiography were excluded from our analysis. We defined exercise-induced pulmonary hypertension (ExPHT) as those with peak estimated systolic pulmonary artery pressure (SPAP) ≥60mmHg or delta SPAP defined as differences between rest and peak SPAP ≥20mmHg.

Results

The mean age was 61±15 years old and 70 (61%) were male. Of those, 8 (7.8%) had mild MR, 32 (31.1%) had moderate MR, and 63 (61.2%) had severe MR. 60 (52.2%) patients had ExPHT. A total of 27 cases of new-onset AF were found during follow-up where the ExPHT group had higher prevalence of new-onset AF than the non-ExPHT group (35% vs. 11%, p=0.002). Those with ExPHT had significantly stronger association with shorter event-free survival time of new-onset AF (log-rank p&lt;0.001, Figure). When adjusted for age, sex, body surface area, the American Society of Echocardiography MR grade, left atrial dimension, peak systolic blood pressure and heart rate, the multivariable Cox regression analysis showed that those with ExPHT had a hazard risk of 3.1 ([95% CI 1.1–9.1], p=0.039) for new-onset of AF.

Conclusions

Exercise-induced pulmonary hypertension predicted incident of new-onset AF in those with primary MR. Exercise echocardiography is expected to play an important role in decision making with regards to the optimal timing for surgical intervention in primary MR.

Figure 1

Funding Acknowledgement

Type of funding source: None

P1493Prognostic significance of right ventricular function during exercise in patients with non-obstructive hypertrophic cardiomyopathy

Background

Hypertrophic cardiomyopathy (HCM) is a heterogeneous condition that may present crucial complication including life-threatening arrhythmia and sudden cardiac death. However, the risk stratification of HCM without left ventricular outflow tract (LVOT) obstruction had not been fully elucidated. Moreover, although recent studies have revealed the right ventricle (RV) involvement of HCM, the prognostic importance of RV function during exercise is unclear.

Purpose

To investigate the prognostic significance of RV function in patients with non-obstructive HCM using exercise stress echocardiography (ESE).

Methods and results

This study conducted on 100 HCM patients (age 62.9±13.6 years, 63% men) with preserved left ventricular ejection fraction who underwent ESE using semi-supine bicycle ergometer. Ten patients with significant LVOT obstruction (≥30mmHg) were excluded and 9 were also excluded because of the inadequate imaging quality or insufficiency of data. Among remaining 81 non-obstructive HCM patients, 9 patients suffered from HCM related cardiac events including cardiac death, unexpected hospitalization, life-threatening arrhythmias, and new-onset of syncope during the mean follow up period of 2.6±1.6 years. A multivariate Cox Hazard analysis revealed that low tricuspid annular plane systolic excursion during exercise (Ex-TAPSE, cut-off: 24mm) was an independent predictor of cardiac events. (hazard ratio: 18.66, 95% confidence interval: 3.66–338.46, P<0.001) The estimated cumulative cardiac event free survival using the Kaplan-Meier method was significantly lower in patients with reduced Ex-TAPSE (<24mm) than those with preserved Ex-TAPSE (Log-rank, P<0.01).

K-M curve according to Ex-TAPSE

Conclusion

Ex-TAPSE had a strong predictive value of clinical outcomes in non-obstructive HCM patients. Right ventricular function during exercise may have crucial role in the risk stratification of non-obstructive HCM.

Impact of an ultrasound-guided radiofrequency ablation training program on the outcomes in patients with hepatocellular carcinoma

PURPOSE

The aim of this study was to retrospectively evaluate the impact of a training program on the safety and efficacy of percutaneous ultrasound-guided radiofrequency ablation (RFA) for the treatment of hepatocellular carcinoma (HCC).

MATERIALS AND METHODS

A total of 227 patients with 296 HCC nodules who underwent percutaneous RFA with or without transcatheter arterial chemoembolization at our institution were included. There were 163 men and 64 women with a mean age of 74.2±8.3 (SD) years (range: 41-89 years). Percutaneous ultrasound-guided RFA was performed by three trainees (205 HCC nodules in 157 patients) or a mentor (91 HCC nodules in 70 patients) after preprocedural preparation including planning ultrasonography. We compared background-related, tumor-related, and treatment-related factors, and local recurrence and complication rates between the trainee group and the mentor group. Similarly, we compared these variables among the years 2015, 2016, and 2017 for trainee group.

RESULTS

The proportion of easy-to-treat tumors in the trainee group (109/205; 53.2%) was greater than that in the mentor group (33/91; 36.3%) (P=0.020). No significant differences were observed in procedure difficulty among the years 2015, 2016, and 2017 for trainee group (easy-to-treat HCC nodules: 25/47; 53.2% vs. 39/79; 49.4% vs. 45/79; 57.0%. P=0.775). The local recurrence rate in the trainee group was 8.8% (18/205 HCC nodules) which was equivalent to 7.7% in the mentor group (7/91 HCC nodules). No significant differences were observed in local recurrence rate (8.8% vs. 7.7%, respectively; P=0.621) and major complication rate (1.3% vs. 1.4%, respectively; P=0.999) between the trainee group and the mentor group. No significant differences were observed in local recurrence rates ([5/47; 10.6%] vs. [11/79; 13.9%] vs. [2/79; 2.5%]) (P=0.109) and major complication rates ([1/36; 2.8%] vs. [1/62; 1.6%] vs. [0/59; 0%]) (P=0.701) between the years 2015, 2016, and 2017 for trainee group.

CONCLUSION

A well supervised training program that includes planning ultrasonography fosters the efficacy and treatment quality of RFA for HCC.

Principal component analysis of three-dimensional face shape: Identifying shape features that change with age

BACKGROUND

The types of shape feature that constitutes a face have not been comprehensively established, and most previous studies of age-related changes in facial shape have focused on individual characteristics, such as wrinkle, sagging skin, etc. In this study, we quantitatively measured differences in face shape between individuals and investigated how shape features changed with age.

METHODS

We analyzed three-dimensionally the faces of 280 Japanese women aged 20-69 years and used principal component analysis to establish the shape features that characterized individual differences. We also evaluated the relationships between each feature and age, clarifying the shape features characteristic of different age groups.

RESULTS

Changes in facial shape in middle age were a decreased volume of the upper face and increased volume of the whole cheeks and around the chin. Changes in older people were an increased volume of the lower cheeks and around the chin, sagging skin, and jaw distortion.

CONCLUSION

Principal component analysis was effective for identifying facial shape features that represent individual and age-related differences. This method allowed straightforward measurements, such as the increase or decrease in cheeks caused by soft tissue changes or skeletal-based changes to the forehead or jaw, simply by acquiring three-dimensional facial images.

Predictors of Exercise-Induced Pulmonary Hypertension in Patients with Asymptomatic Degenerative Mitral Regurgitation: Mechanistic Insights from 2D Speckle-Tracking Echocardiography

Presence of exercise-induced pulmonary hypertension (EIPH) in asymptomatic degenerative mitral regurgitation (DMR) determines prognosis. This study aimed to elucidate the mechanism and predictors of EIPH in asymptomatic DMR. Ninety-one consecutive asymptomatic patients with DMR who underwent exercise stress echocardiography were prospectively included. We obtained various conventional echocardiographic parameters at rest and during peak exercise, as well as left atrial (LA) function at rest using 2-dimensional speckle-tracking analysis. The 25 patients (33.3%) with EIPH were significantly older and had a greater ratio of mitral peak velocity of early filling to early diastolic mitral annular velocity during peak exercise than those without EIPH. LA strain (LAS)-s and LAS-e, indices of LA reservoir and conduit function, respectively, were significantly lower in those with EIPH than in those without EIPH. Multivariate analysis indicated that LAS-s was the only resting echocardiographic parameter that independently predicted EIPH, with a cut-off value of 26.9%. Furthermore, Kaplan-Meier curve analysis showed that symptom-free survival was markedly lower among those with reduced LAS-s. In conclusion, decreased LA reservoir function contributes to EIPH, and LAS-s at rest is a useful indicator for predicting EIPH in asymptomatic patients with DMR.

Age-related changes in dermal fiber-like structures in facial cheeks

BACKGROUND/PURPOSE

Despite recent progress in non-invasive measurement methods, such as in vivo laser confocal microscopy (CLSM), it is difficult to quantitatively measure age-related changes in dermal fibrous structures in the face using these methods and qualitative characteristics. We used characteristics extracted from the analysis of CLSM images to quantitatively investigate the effects of aging on dermal fibrous structures in the face.

METHODS

CLSM images of dermal fibrous structures were obtained from 90 Japanese females, ranging in age from 20 to 60 years. The feature values of CLSM images were extracted using image analysis methods, such as short-line segment-matching processing and spatial frequency analysis. The qualitative characteristics of the dermal fibrous structures in the CLSM images were obtained by principal component analysis (PCA) of these feature values. The fibrous structures were scored on the basis of qualitative characteristics and then age-related changes in the scores among the subjects were quantitatively evaluated.

RESULTS AND CONCLUSION

The PCA results showed that there were two characteristics in the images of fibrous structures: clearness and directionality. The clearness of fibrous structures decreased and directionality isotropy increased with age.

Aortic annulus displacement assessed by contrast left ventriculography during invasive coronary angiography as a predictor of adverse events

BACKGROUND

We propose the use of aortic annulus displacement (AAD) detected on contrast left ventriculography (LVG) during invasive coronary angiography as a marker of left ventricular (LV) long-axis shortening. In the present study, we aimed to investigate whether AAD is associated with adverse events in patients who underwent coronary angiography because of suspected coronary artery disease.

METHODS

In this retrospective study, we evaluated the medical records of 998 consecutive patients who underwent invasive coronary angiography and LVG. LV lengths were measured from the apex to the aortic valve insertion by using LVG images. AAD (%) was calculated as [(LV end-diastolic length-LV end-systolic length)/LV end-diastolic length]×100.

RESULTS

The participants' median age was 67 years. Ninety-six adverse events (composite events; all-cause death, 39; congestive heart failure, 21; late revascularization, 34; and myocardial infarction, 2) were observed during a median follow-up period of 3.1 years. In multivariate Cox regression analysis, adverse events were associated with lower AAD (hazard ratio, 0.703; p=0.002), after adjusting for traditional risk factors and coronary artery stenosis. The area under the curve of AAD for predicting adverse events was greater than that of LV ejection fraction (0.656 vs. 0.541, p<0.05).

CONCLUSIONS

AAD was superior to LV ejection fraction as a predictor of adverse events in patients with and without coronary arterial stenosis. AAD may be the optimal method for assessing longitudinal LV systolic function in the catheter laboratory.

The relationship between dermal papillary structure and skin surface properties, color, and elasticity

BACKGROUND/PURPOSE

The skin contains an undulating structure called the dermal papillary structure between the border of the epidermis and dermis. The physiological importance of the dermal papillary structures has been discussed, however, the dermal papillary structures have never been evaluated for their contribution to skin appearance. In this study, we investigated the correlation between the dermal papillary structure and skin color and elasticity. In addition, the relationship was validated with skin model experiments.

METHODS

The dermal papillary structures in the skin of the female cheek were quantitatively measured by in vivo confocal laser scanning microscopy images. In addition, the skin color and elasticity were measured at the same site. A skin model with dermal papilla-like structures was created by referring to the optical and shape properties of the skin using agar gel and a scattering sheet.

RESULTS

Correlations were found between the dermal papillary structures and skin color irregularity and skin elasticity. These relationships were verified by the experiments employing a skin model.

CONCLUSION

The results of this study indicated that the dermal papillary structure is also an important factor for skin appearance such as color and elasticity.

Epidemiological survey of definite cases of Meniere's disease collected by the seventeen members of the Meniere's Disease Research Committee of Japan in 1975--1976

Between Aril 1975 and December 1976, the second nationwide survey of Meniere's disease in Japan was made by the 17 members of the Meniere's Disease Research Committee of Japan. The epidemiological data from 520 patients with definite Meniere's disease were analyzed in comparison with those from the 126 patients in the non-Meniere vertiginous group (Control A) and the 228 patients in the rhinolaryngological group (Control B). The male:female ratio of definite cases of Meniere's disease was almost the same, and the age distribution peaked at the age group of 40--49 years for males, while the peak for females was at the age group of 30--39 years. 5.8% of the 520 patients had a close relative who also suffered from Meniere's disease. From the epidemiological features, it may appear that the occurrence of vertiginous attacks in Meniere's disease is influenced much more by individual than by environmental factors. However, this feature can be considered as another evidence of the psychosomatic disorders involved in Meniere's disease.

Changes in dermal papilla structures due to aging in the facial cheek region

BACKGROUND/PURPOSE

In the past, it has been possible to measure the dermal papilla structures which are undulations between the epidermis and dermis by noninvasive method. However, almost all of previous studies were not intended to measure facial skin but another site of body. Here, we investigated age-dependent alterations for dermal papilla structures in the facial cheek region after elucidating the difference of characteristics between the body site.

METHODS

The surface of the dermis was observed under scanning electron microscope (SEM) using face and abdominal skin biopsy samples. A total of 90 Japanese women were investigated by in vivo confocal laser microscope (CLSM). The number and the shape in the horizontal cross-sectional images of the dermal papilla were analyzed.

RESULTS

The facial skin had different characteristics in comparison to the abdominal skin by SEM observation. Under CLSM observation, we found abnormal dermal papilla structures which were accompanied by spots or enlarged pore areas and eliminated these structures from our analysis. We revealed a decrease in the number of normal dermal papilla structures with age and large individual differences at younger ages.

CONCLUSION

We found abnormal dermal papilla structures and differences in the dermal papilla structures between face and other body site. With these taken into consideration, we could precisely investigate the aging alteration of normal dermal papilla structures in the face.

Fundamental study of osteoclast chemotaxis toward chemoattractants expressed in periodontitis

BACKGROUND AND OBJECTIVE

Periodontitis is a chronic inflammatory disease that leads to bone resorption by osteoclasts (OCs). Several factors contribute to the differentiation of OCs from hematopoietic precursors. Cellular chemotactic factors are expressed in periodontitis tissue, but the effects of these chemoattractants on OCs are not well understood. Here we examined the effects of chemoattractants produced in inflamed periodontal tissue on OC chemotaxis.

MATERIAL AND METHODS

Rat bone-marrow OCs were cultured in OC culture medium for 3 or 6 d. Using EZ-TAXIScan™, the chemotactic response of these OCs to several chemoattractants [monocyte chemotactic protein-1; macrophage inflammatory protein 1α; regulated on activation, normal T-cell expressed and secreted; stromal cell-derived factor-1α; and complement activation product 5a (C5a)] was measured. In addition, we measured the effect of C5a-specific inhibitors on chemotactic responses toward C5a. The recorded chemotactic responses were quantitatively analysed using ImageJ software.

RESULTS

Chemoattractants associated with periodontal disease significantly increased the chemotactic activity of differentiated rat OCs in a concentration-dependent manner, with C5a inducing the highest chemotactic activity of OCs cultured for 3 or 6 d. The C5a-specific inhibitor significantly inhibited chemotaxis toward C5a in a concentration-dependent manner.

CONCLUSION

We suggest that C5a plays an important role in pathologic bone resorption in periodontal disease by stimulating the chemotaxis of OCs. Therefore, C5a is a potential target for the treatment of periodontal disease.

Activation of p38 mitogen-activated protein kinase in the dorsal root ganglion contributes to pain hypersensitivity after plantar incision

BACKGROUND

The phosphorylation of p38 mitogen-activated protein kinase (MAPK) in the dorsal root ganglion (DRG) promotes primary afferent sensitization. The role of p38MAPK signaling in the DRG in the pathogenesis of plantar incision hyperalgesia has not been investigated.

RESULTS

Levels of phosphorylated p38MAPK (p-p38MAPK) obviously increased in the DRG after plantar incision. Unmyelinated and myelinated DRG neurons that express p-p38MAPK contained small to medium cell bodies, suggesting that p-p38MAPK expression is induced in neurons with C- and Aδ-fibers. The p-p38MAPK inhibitors FR167653 or SB203580 inhibited incision-induced mechanical hypersensitivity and spontaneous pain behavior. The systemic administration of tumor necrosis factor-α (TNF-α) inhibitor prevented subsequent incision-induced activation of p38MAPK in the DRG and alleviated mechanical hypersensitivity after the incision.

CONCLUSIONS

p38MAPK signaling in the DRG plays a crucial role in the development of primary afferent sensitization and pain behavior caused by plantar incision.

Early diastolic function during exertion influences exercise intolerance in patients with hypertrophic cardiomyopathy

BACKGROUND

Hypertrophic cardiomyopathy (HCM) patients with preserved left ventricular ejection fraction (LVEF) often develop dyspnea and exercise intolerance. Diastolic dysfunction may contribute to exercise intolerance in these patients. This study aimed to clarify our hypothesis as to whether diastolic function rather than systolic function would be associated with exercise intolerance in HCM using two-dimensional (2D) speckle tracking echocardiography during exercise.

METHODS

Thirty-three HCM patients (mean age 59.3 ± 15.7 years) underwent 2D speckle tracking echocardiography at rest and during submaximal semi-supine bicycle exercise. Global longitudinal strain (LS), LS rate during systole (LSRs), early diastole (LSRe), and late diastole (LSRa) were measured. The symptom-limited cardiopulmonary exercise testing was performed using a cycle ergometer for measuring the peak oxygen consumption (peak [Formula: see text]).

RESULTS

In the multivariate linear regression analysis, peak [Formula: see text] did not associate with strain or strain rate at rest. However, peak [Formula: see text] correlated with LS (β = -0.403, p = 0.007), LSRe (β = 6.041, p = 0.001), and LSRa (β = 5.117, p = 0.021) during exercise after adjustment for age, gender, and heart rate. The first quartile peak [Formula: see text] (14.2 mL/min/kg) was assessed to predict exercise intolerance. The C-statistic of delta LSRe was 0.74, which was relatively greater than that of delta LS (0.70) and delta LSRa (0.58), indicating that early diastolic function rather than systolic and late diastolic function affects exercise intolerance.

CONCLUSIONS

LSRe during exercise is closely associated with the peak [Formula: see text]. Early diastolic function during exercise is an important determinant of exercise capacity in patients with HCM.

Global longitudinal strain by two-dimensional speckle tracking imaging predicts exercise capacity in patients with chronic heart failure

BACKGROUND

Left ventricular ejection fraction (LVEF) predicts mortality in patients with chronic heart failure (CHF). However, a weak correlation was found between LVEF and peak oxygen uptake ([Formula: see text]) in CHF patients. Global longitudinal strain measured by two-dimensional (2D) strain is regarded as a more useful predictor of cardiac events than LVEF. We investigated whether 2D strain obtained at rest could predict peak [Formula: see text] in patients with CHF.

METHODS

Fifty-one patients (mean age of 54.0 ± 12.0 years, 14 females, LVEF 46.0 ± 15.0%) with stable CHF underwent resting echocardiography and cardiopulmonary exercise testing. Leg muscle strength was measured for the evaluation of peripheral factors. Global longitudinal strain (GLS) in the apical 4-, 3-, and 2-chamber views and global circumferential strain (GCS) in the parasternal mid short-axis view were measured.

RESULTS

In all patients, peak [Formula: see text] correlated with leg muscle strength (r = 0.55, p < 0.0001), LVEF (r = 0.46, p < 0.001), GLS (r = -0.45, p < 0.001), and GCS (r = -0.41, p = 0.005), respectively. No significant correlation was found between the ratio of early transmitral velocity to peak early diastolic mitral annulus velocity (E/E') and peak [Formula: see text]. In the patients with heart failure and reduced LVEF, a multiple stepwise linear regression analysis based on leg muscle strength, LVEF, E/E', GLS, and GCS was performed to identify independent predictors of peak [Formula: see text], resulting in leg muscle strength and GLS (R (2) = 0.888) as independent predictors of peak [Formula: see text].

CONCLUSION

Global longitudinal strain at rest could possibly predict exercise capacity, which appeared to be more useful than LVEF, E/E', and GCS in CHF patients with reduced LVEF.

Hyperventilation and cold-pressor stress echocardiography combined with automated functional imaging non-invasively detected vasospastic angina

A 47-year-old male presented with chest discomfort while sleeping. The patient was suspected of having vasospastic angina (VSA) and underwent hyperventilation and cold-pressor stress echocardiography. No chest pain, ECG changes or decreased wall motion was found. However, automated function imaging (AFI) showed decreased peak systolic strain at the apex and postsystolic shortening at both the apex and inferior wall, which was not found before the test. The provocation test revealed 99% stenosis in the right coronary artery #2 at a dose of 50 μg acetylcholine and 90% stenosis in the left coronary artery #8 at a dose of 100 μg. The patient was thus diagnosed as having VSA. The present case demonstrates the usefulness of AFI combined with hyperventilation and cold-pressor stress echocardiography as a screening examination for VSA.

Ménière's disease and delayed endolymphatic hydrops in children

In order to study the characteristics of pediatric patients (< or = 15 years at onset) with endolymphatic hydrops disorders, we selected 5 patients with Ménière's disease (MD) and 3 patients with delayed endolymphatic hydrops (DEH) from 7418 patients who had visited the Neurotological Clinic of the Toyama Medical and Pharmaceutical University Hospital between 1979 and 1999. Clinical features were characterized as follows: (i) pediatric MD patients were rare, comprising approximately 1.5% of all the 337 MD patients in the sample; (ii) a fluctuating hearing loss, strong positive response in glycerol test, high SP/AP amplitude ratio in electrocochleography and moderate positive response in furosemide vestibulo-ocular reflex test were recorded; (iii) in 2 of the 5 pediatric MD patients, vertiginous attacks had persisted for a long period and they had undergone surgical procedures (sac operation and vestibular neurectomy); and (iv) the ipsilateral type of DEH was observed in 2/3 children, and contralateral DEH in 1/3.

Clinical study of elderly patients with Meniere's and related diseases

In order to study the characteristics of elderly patients (70 or over at onset) with endolymphatic hydrops disorders, we selected six patients with Meniere's disease (MD), five patients with delayed endolymphatic hydrops (DEH), and two patients with syphilis of the labyrinth (SL) from 7112 patients who had visited the Neurotological Clinic of the Toyama Medical and Pharmaceutical University Hospital during 1979-1998. Clinical features were characterized as follows: (1) Since 1990, the proportion of elderly patients increased as lifespans lengthened. (2) A narrow fluctuation in hearing, low positive rate on glycerol test, high positive rate of dominant-SP in EcochG, and the moderate abnormal rate of the oculomotor system tests were found. (3) The prognosis was relatively good. From these neurotological observations, it could be concluded that elderly patients with endolymphatic hydrops disorders were characterized by the multipathological finding of the endolymphatic hydrops and the complications of CNS disorders.

Relationship between urinary cadmium and mortality among inhabitants living in a cadmium polluted area in Japan

A 15 year follow-up study of 3119 inhabitants living in a cadmium polluted area was conducted to investigate the influence of environmental cadmium exposure on the mortality. The cumulative survival curves of the subjects with urinary cadmium concentration > or = 10 microg/g creatinine was lower than that of the subjects with < 10 microg/g creatinine in the men aged 50-59 and 60-69 years and in the women aged 60-69 and 70-79 years. In the men aged 50-69 years and the all aged women, the cumulative survival curves became lower in proportion to the increase of urinary cadmium concentration, when the subjects were divided into four groups according to the amount of urinary cadmium concentration (< 5, 5-9.9, 10.1-19.9, > or = 20 microg/g creatinine). These results suggested a dose response relationship between cadmium exposure and mortality.

Epidemic of gastrointestinal tract infection including hemorrhagic colitis attributable to Shiga toxin 1-producing Escherichia coli O118:H2 at a junior high school in Japan

BACKGROUND

An epidemic of gastrointestinal disturbances related to food ingestion occurred at a junior high school in Komatsu, Japan, and was caused by specifically Shiga toxin (Stx) 1-producing Escherichia coli O118:H2, which has not been reported previously in humans. No outbreak of E coli-producing Stx 1 alone had occurred.

METHODS

A total of 526 students and 35 adult staff members who ate the same food at lunch in the school were investigated. Questionnaires about food consumption at lunch were given to all 561 subjects as well as to clinics and hospitals that had treated 79 patients. Stool specimens from 525 subjects, and food, water, and environmental specimens, including cooking utensils, were collected in an attempt to identify the pathogen.

RESULTS

A total of 126 subjects (22.5%) developed a diarrheal illness. The pathogen was isolated from the stool in 131 subjects, 49 of which were asymptomatic, and from a dipper. Salads served over several days were identified as high-risk from food analysis. Gastrointestinal symptoms resembled those associated with previous infections of Stx-producing E coli, but were mild. No cases of the hemolytic-uremic syndrome developed. Headache was present in 87 patients. Three patients underwent surgery for acute appendicitis during this epidemic. Four of five carriers had received an antibiotic effective against the pathogen.

CONCLUSIONS

This outbreak of E coli O118:H2 demonstrated the clinical and epidemiologic features of infection by E coli that produces Stx 1 alone. Infections with such organisms are being recognized increasingly, and the pattern of disease observed may differ from the pattern observed with E coli O157:H7.

Pharmacological effects of BAM-1120, a novel ergoline derivative, on central dopaminergic functions in rats

BAM-1120, an ergoline derivative, has been found to display a relatively high affinity for dopamine D2-like receptor subtypes in a preliminary binding study. This study investigated whether BAM-1120 acts as a dopamine receptor agonist on prolactin-secreting and motor functions. BAM-1120 suppressed hyperprolactinemia induced by pretreatment with reserpine or estradiol in female rats. Furthermore, BAM-1120 was able to shrink a prolactin-secreting pituitary tumor (prolactinoma) in the estradiol-treated female rats. BAM-1120 induced rotations contralateral to the lesion side in rats with unilateral 6-hydroxydopamine-induced lesions of nigrostriatal dopamine pathway at a dose that was at least 30-fold higher than that required for the inhibition of prolactin secretion. These findings suggest that BAM-1120 is characterized as a putative dopamine D2-like receptor agonist that possesses a preference of inhibiting prolactin secretion over activating motor behaviors.