Association between blood pressure classification using the 2017 American College of Cardiology/American Heart Association blood pressure guideline and hypertensive retinopathy

Purpose

We aimed to explore the association of blood pressure (BP) classification using the 2017 American College of Cardiology/ American Heart Association Guideline and the prevalence of hypertensive retinopathy using a nationwide epidemiological database.

Methods

This study is a retrospective observational cross-sectional analysis using the health claims database of the JMDC between 2005 and 2020. We analyzed 280,599 participants who did not take anti-hypertensive medications. Each participant was categorized as having normal BP (systolic BP [SBP] <120 mm Hg and diastolic BP [DBP] <80 mm Hg; n=159,524); elevated BP (SBP 120–129 mm Hg and DBP <80 mm Hg; n=35,603); stage 1 hypertension (SBP 130–139 mm Hg or DBP 80–89 mm Hg; n=54,795); or stage 2 hypertension (SBP ≥140 mm Hg or DBP ≥90 mm Hg; n=30,677). Retinal photography at health check-up was classified as normal, grade 1, grade 2, grade 3, or grade 4 according to the Keith-Wagener-Barker system.

Results

Median (interquartile range) age was 46 (40–53) years, and 50.4% were men. Hypertensive retinopathy which was defined as ≥ Keith-Wagener-Barker system grade 1, was observed in 16,836 participants (6.0%). Multivariable logistic regression analysis showed that, compared with normal BP, elevated BP (odds ratio [OR] 1.30, 95% confidence interval [CI] 1.23–1.38), stage 1 hypertension (OR 1.71, 95% CI 1.64–1.79), and stage 2 hypertension (OR 4.10, 95% CI 3.93–4.28) were associated with higher prevalence of hypertensive retinopathy. Even among 92,121 participants without obesity, high waist circumference, diabetes mellitus, dyslipidemia, cigarette smoking, and alcohol drinking, multivariable logistic regression analysis showed that, compared with normal BP, elevated BP (odds ratio 1.34, 95% CI 1.19–1.51), stage 1 hypertension (OR 1.79, 95% CI 1.61–1.98), and stage 2 hypertension (OR 4.42, 95% CI 4.00–4.92) were associated with higher prevalence of hypertensive retinopathy. The association between BP category and hypertensive retinopathy was observed in all subgroups stratified by age or sex.

Conclusion

Our investigation showed that the prevalence of hypertensive retinopathy increased with the blood pressure category, suggesting that atherosclerotic change could start even in elevated BP and stage 1 hypertension.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): This work was supported by grants from the Ministry of Health, Labour and Welfare, Japan (19AA2007 and H30-Policy-Designated-004) and the Ministry of Education, Culture, Sports, Science and Technology, Japan (17H04141).

Association between surgical treatment and in-hospital mortality in patients with infective endocarditis stratified by NYHA classification: a nationwide retrospective study in Japan

Background

Heart failure (HF) is one of the major complications of infective endocarditis (IE). The ESC guideline described that surgical treatment should be performed for the patients with IE complicated with HF. However, decision making of surgical indication in real-world clinical setting is not easy for patients with IE concomitant with HF due to complicated conditions, and the clinical benefit of surgical intervention for IE and HF is unclear.

Purpose

We sought to uncover the association between surgical treatment and in-hospital mortality among the patients admitted for community-acquired IE respectively according to the severity of HF symptoms (NYHA class I to IV).

Methods

We studied 3,403 patients diagnosed as IE (mean age 65.9 years, 61.6% males) with records of baseline NYHA classification (I to IV) who survived for more than 2 days, using the Diagnosis Procedure Combination database, a nationwide inpatient database in Japan. Patients were classified into four groups: 919 patients (27.0%) in NYHA I, 1,007 patients (29.6%) in NYHA II, 767 patients (22.5%) in NYHA III, and 710 patients (20.9%) in NYHA IV. A multivariable logistic regression model adjusted for age, gender, Barthel Index, Charlson Comorbidity Index, and usage of inotropic therapy at admission was performed to evaluate the association between the surgical treatment and in-hospital mortality.

Results

Patients with higher NYHA classification were significantly older and were more likely to be female than those with lower NYHA classification. At admission, patients with higher NYHA classification had lower baseline activities and higher comorbidities, and also had more complications including stroke, shock and disseminated intravascular coagulation than those with lower NYHA classification. In-hospital mortality was seen in 406 patients (11.9%) in the entire cohort. The mortality rate significantly increased with the NYHA class (NYHA I, 3.6%; NYHA II, 8.4%; NYHA III, 11.9%; NYHA IV, 27.9%: p<0.001). According to the multivariable logistic regression analysis, surgical treatment was independently associated with lower in-hospital mortality (Odds ratio 0.395, 95% Confidence Interval 0.297–0.526; p<0.001). A fragmentated analysis in each NYHA classification showed that the survival benefit of surgical intervention was pronounced in patients with higher NYHA class (Figure). The limitation of our study was including the potential unmeasured confounders, which lead to overestimate the relationship between the surgical treatment and in-hospital mortality even after excluding the critically ill patients who died within 2 days and adjusting for the measured confounders.

Conclusion

Surgical treatment was associated with lower in-hospital mortality among the patients with IE complicated with HF, particularly among those with more advanced HF status. Our study implies that surgical treatment might be beneficial for the patients with advanced HF.

Funding Acknowledgement

Type of funding source: None

Geographic variation in the outcome of patients hospitalized for heart failure: analysis of a nationwide inpatient database

Background

The prevalence of heart failure (HF) is increasing in developed countries. Considering the significant socioeconomic burden of HF, nationwide actions against HF are indispensable. To that end, relevant information on regional variations among HF patients are required.

Purpose

We aimed to explore the geographic variations in the characteristics and outcomes of hospitalized HF patients using a nationwide inpatient database.

Methods and results

Using the Diagnosis Procedure Combination database which is a nationwide inpatient database in Japan, we carried out a comprehensive analysis of 447,818 hospitalized patients with HF (median age 81 years, 238,192 men) who were admitted between January 2010 and March 2018 in Japan. We divided the study population into seven geographical regions based on the location of the admitted hospital. Background characteristics were almost similar among all seven regions. The implementation rates of intubation, hemodialysis, inotropic agent, and advanced circulatory supports including intra-aortic balloon pumping and extracorporeal membrane oxygenation varied among the seven regions. There was a significant difference in the length of hospital stay and the in-hospital mortality among the seven regions. The multivariable logistic regression analysis including baseline clinical charasteristics and medication administered within two days after hospital admission fitted with a generalized estimation equation for in-hospital mortality showed that there was still a significant difference in the in-hospital mortality among the seven regions (Table).

Conclusion

The analysis of a nationwide inpatient database showed that geographical variations existed regarding the outcomes of patients hospitalized for HF. This suggests the necessity of further efforts to establish a standardized medical care system in this era of HF pandemic.

Funding Acknowledgement

Type of funding source: Public grant(s) – National budget only. Main funding source(s): Grants from the Ministry of Health, Labour and Welfare, Japan (19AA2007 and H30-Policy-Designated-004) and the Ministry of Education, Culture, Sports, Science and Technology, Japan (17H04141)

Cardiovascular health metrics of 122,788 couples: analysis of a nationwide epidemiological database

Introduction

The American Heart Association suggests that cardiovascular health (CVH) metrics based on established risk factors and behaviors to reduce the morbidity and mortality of cardiovascular disease. Couples share environmental and lifestyle habits, and therefore, there can be an intra-couple correlation of CVH metrics. However, the clinical data on the association of the CVH metrics among couples are limited.

Purpose

We aimed to explore the intra-couple relationship of the AHA-defined cardiovascular health metrics using a nationwide epidemiological database.

Methods

This study is a retrospective observational cross-sectional analysis using the health claims database of the Japan Medical Data Center between January 2005 and December 2016. We modified the American Heart Association CVH metrics and defined ideal CVH component as following: 1) nonsmoking, 2) body mass index <25 kg/m2, 3) physical activity at goal, 4) untreated blood pressure <120/80 mm Hg, 5) untreated fasting glucose <100 mg/dL, and 6) untreated total cholesterol <200 mg/dL.

Results

We analyzed 122,788 heterosexual couples enrolled in the Japan Medical Data Center database. The average age of participants was 50.2±9.5 years in men and 48.6±8.9 years in women. Good correlation was observed between couples in terms of the modified ideal CVH metrics (Figure 1A). The prevalence of meeting ≥5 ideal components in the female partners increased from 31% in the male partners meeting no ideal components to 55% in those meeting 6 ideal components. The concordance ratio is particularly higher in the component of smoking status, blood pressure, and fasting glucose level. A man who meets ≥5 ideal components probably had a woman partner who meets ≥5 ideal components (Odds ratio 1.6, 95% CI: 1.6–1.7, p<0.001). The P value for the McNemar test was significant for all components, indicating that women apparently met ideal metrics for metrics in discordant Couples (Figure 1B).

Conclusion

Our investigation showed that there was a good intra-couple correlation of the ideal modified CVH metrics, suggesting the potential of couple-based assessment and management for improving CVH status.

Funding Acknowledgement

Type of funding source: None

Association between insulin resistance and left ventricular diastolic dysfunction in non-diabetic general population

Background

Insulin resistance due to visceral fat accumulation plays a central role in the development of diabetic mellitus and subsequent cardiovascular disease. Abdominal obesity and diabetic mellitus are associated with the progression of left ventricular diastolic dysfunction which is the major structural abnormality in patients with heart failure. However, whether insulin resistance influences left ventricular diastolic dysfunction in non-diabetic subjects is unclear.

Purpose

In this study, we aimed to clarify the association between insulin resistance and left ventricular diastolic dysfunction in non-diabetic general population.

Methods

We examined 2,572 non-diabetic subjects with preserved left ventricular systolic function (ejection fraction ≥50%) and without a past history of diabetic mellitus, heart failure, coronary artery disease, atrial fibrillation, stroke, moderate to severe valvular disease, who underwent medical check-ups at the University of Tokyo Hospital from January 2009 to December 2018. Diabetes mellitus was defined as fasting glucose level ≥126 mg/dL or a subject's use of oral antidiabetic medications or insulin. We calculated the Homeostasis Model Assessment-Insulin Resistance (HOMA-IR) score [HOMA-IR = fasting glucose (mg/dL) × insulin (μU/mL) / 405], and defined insulin resistance as HOMA-IR ≥2.5. Left ventricular diastolic function was assessed by echocardiography, using tissue doppler analysis (E/E' ratio in septal and lateral). Visceral adiposity was assessed as visceral fat volume measured by computed tomography scanner.

Results

Mean age was 53.3±9.8 years, and 1,746 subjects (67.9%) were male. Overall, HOMA-IR was 1.1 on average, and HOMA-IR ≥2.5 was observed in 5.0% of study population. BMI and the prevalence of obesity were higher in subjects with HOMA-IR ≥2.5 than in those without. There was no significant difference in left ventricular ejection fraction between HOMA-IR ≥2.5 and ≤2.5. E/E' ratio in septal and lateral were higher in subjects with HOMA-IR ≥2.5 than in those without. Multivariable logistic regression analysis demonstrated that obesity and waist circumference, visceral fat volume were independently associated with HOMA-IR ≥2.5, however, age, hypertension, hypercholesterolemia were not. Further, multiple regression analysis including insulin resistance, age, male gender, obesity, hypertension, hypercholesterolemia, cigarette smoking and visceral fat volume, showed that insulin resistance was an independent determinant of increasing E/E' in both septal and lateral, whereas visceral fat volume was not (Figure 1).

Conclusion

The results of the present study suggest that insulin resistance due to visceral fat accumulation might be associated with the development of left ventricular diastolic dysfunction in non-diabetic general population without overt cardiovascular disease.

Figure 1

Funding Acknowledgement

Type of funding source: None

Effect of Small Focus on Electron Heating and Proton Acceleration in Ultrarelativistic Laser-Solid Interactions

Acceleration of particles from the interaction of ultraintense laser pulses up to 5×10^{21}  W cm^{-2} with thin foils is investigated experimentally. The electron beam parameters varied with decreasing spot size, not just laser intensity, resulting in reduced temperatures and divergence. In particular, the temperature saturated due to insufficient acceleration length in the tightly focused spot. These dependencies affected the sheath-accelerated protons, which showed poorer spot-size scaling than widely used scaling laws. It is therefore shown that maximizing laser intensity by using very small foci has reducing returns for some applications.

P198 Validation of the updated blood pressure classification based on the ACC/AHA guidelines in the perspective of subclinical atherosclerosis in general population

Background

American College of Cardiology (ACC) and American Heart Association (AHA) revised their guideline for hypertension in 2017, and the threshold of normal blood pressure (BP) was lowered, in the perspective of the prevention of optimal prevention of cardiovascular diseases. On the other hand European Society of Cardiology and European Society of Hypertension updated their guideline in 2018. However, the cut off value of blood pressure for hypertension was not changed (sBP ≥ 140 mmHg or dBP ≥ 90 mmHg). Therefore, the validity of the updated guideline of ACC/AHA still remains controversial, and there is so far no evidence regarding the BP category according to the ACC/AHA guidelines in general population.

Purpose

We aimed to clarify the association between the updated BP classification and carotid intima-media thickness (IMT), as a marker of subclinical atherosclerosis, in general population using a community-based cohort.

Methods

We analyzed 1,241 subjects undergoing medical check-ups at the University of Tokyo Hospital. Study subjects were categorized into 3 groups based on their BP levels: normal pressure (sBP < 130 mmHg and dBP < 80 mmHg); stage 1 hypertension (130 mmHg ≤ sBP < 140 mmHg or 80 mmHg ≤ dBP< 90 mmHg); and stage 2 hypertension (sBP ≥ 140 mmHg or dBP ≥ 90 mmHg, including subjects prescribed with antihypertensive agents). We defined carotid plaque as IMT ≥ 1.1 mm.

Results

Out of 1,241 subjects, 556 patients (44.8%) were categorized in the normal BP group, whereas 236 subjects (19.0%) and 449 subjects (36.2%) were categorized in the stage 1 and stage 2 hypertension groups, respectively. Among subjects categorized in the stage 2 hypertension group, 348 subjects (77.5%) patients were taking antihypertensive medications. Percentage of male gender, and age increased with BP category. Classical CVD risk factors such as diabetes mellitus and hypercholesterolemia were common in subjects in the hypertension groups. IMT increased as the BP category progressed from normal BP to stage 2 hypertension. The prevalence of carotid plaque also increased with an increase in BP. Univariate regression analysis showed the linear association between the BP category and prevalence of carotid plaque. Multivariable logistic regression analysis demonstrated that BP category as well as age ≥60 years, male gender, body mass index ≥25 kg/m2, and diabetes mellitus were independently associated with carotid plaque formation. BP category was associated with the prevalence of carotid plaque formation in any subgroup divided by age (< 60 years old, and ≥60 years old) or gender.

Conclusions

Thickening of IMT developed in stage 1 hypertension, and further increased in stage 2 hypertension even in general population, indicating the importance of the therapeutic intervention according to the updated ACC/AHA guideline for hypertension.

Abstract P198 Figure.

P5293Effect of metabolically health obesity on carotid intima-media thickness in general population: a community-based cohort study

Introduction

Obesity is a common and independent risk factor for all-cause mortality. More specifically, obesity is a major component of atherosclerosis in association with metabolic disorders including metabolic syndrome (MetS), resulting in various cardiovascular diseases (CVD). Alternatively, obese subjects without MetS are prevalent, also referred to as metabolically healthy obesity (MHO). However, most preceding studies regarding MHO have been limited by small cohorts. Therefore, the effect of MHO on atherosclerosis in the general population remains unclear.

Purpose

In this study, we sought to clarify the effect of MHO on carotid intima-media thickness (IMT) as a marker of early stage atherosclerosis using a community-based cohort in general population.

Methods

We examined subjects who underwent medical check-up at our University Hospital. We defined obesity as body mass index ≥25.0 kg/m2. Abdominal obesity, defined as waist circumstance at umbilical level ≥85 cm in men and ≥90 cm in women, was obligatory for the diagnosis of MetS. In addition to abdominal obesity, any two of the following three abnormalities should be observed for the diagnosis of MetS, [1] Dyslipidemia: triglyceride ≥150 mg/dL, HDL-C <40 mg/dL, or use of lipid lowering medication, [2] Hypertension: systolic blood pressure ≥130 mmHg, diastolic blood pressure ≥85 mmHg, or use of antihypertensive medication, and [3] Hyperglycemia: fasting plasma glucose ≥110 mg/dL or use of hypoglycemic medication. MHO was defined as obese subjects without MetS, whereas we defined metabolically unhealthy obesity (MUO) as obese subjects with MetS. We defined carotid plaque as IMT ≥1.1 mm.

Results

Among 1,241 subjects, 857 subjects (69%) were categorized in the normal body weight group, whereas 275 subjects (22%) were categorized as MHO, and 109 subjects (9%) were categorized as MUO. Compared to non-obese subjects, prevalence of classical cardiovascular risk factors including hypertension, diabetes mellitus, and dyslipidemia increased in subjects with MHO, and further increased in those with MUO. IMT was higher in obese subjects compared to those without obesity. Similarly, the prevalence of carotid plaque formation was also higher in obese subjects. Multivariable logistic regression analysis demonstrated that age ≥60 years, male sex, hypertension, diabetes mellitus, MHO subjects (Odds ratio [OR]; 1.6, p=0.005), and MUO subjects (OR 1.7, p=0.04) were independently associated with carotid plaque formation. There was no statistical difference in the risk of carotid plaque formation between subjects with MHO and MUO.

IMT and Carotid Plaque

Conclusions

IMT and the prevalence of carotid plaque are higher in both subjects with MHO and MUO compared to non-obese subjects in the general population. We need to take obesity regardless of the presence of MetS into consideration as high-risk subjects for subsequent CVD.

P4389Effect of cigarette smoking on carotid artery atherosclerosis: a community-based cohort study

Background

Cigarette smoking is closely associated with the development of cardiovascular diseases (CVD), and the European Society of Cardiology/European Atherosclerosis Society (ESC/EAS) guidelines recommend smoking bans.On the other hand, the relationship between cigarette smoking and subclinical atherosclerosis has not been fully studied. Carotid intima-media thickness (cIMT) is commonly used as a subclinical atherosclerosis marker, and a carotid plaque feature is also known to be an important predictor of cardiovascular diseases.

Purpose

We sought to clarify the association between cigarette smoking and subclinical atherosclerosis by evaluating carotid plaque including cIMT and carotid plaque features in general population.

Methods and results

Among 1,209 participants with no prior coronary artery disease who received a medical check-up with cardiovascular examination at our institution, 450 participants (37.2%) were smokers (including both past and current smokers). We defined carotid plaque as cIMT ≥1.1 mm and high-risk plaque as carotid plaque with hypoechoic dominant and/or plaque ulceration. The value of cIMT and the rate of carotid plaque were not different between smokers and never smokers (Figure A & B). However, the rate of carotid high-risk plaque was significantly higher in participants with smokers than those with never smokers (29.7%, vs 23.5%, p=0.011) (Figure C). Even after adjustment with covariates including age, gender and traditional cardiovascular risk factors, cigarette smoking was independently associated with high-risk plaque formation (odds ratio 1.384, 95% CI 1.020–1.877; p=0.037). According to the subgroup analysis classified by age, cigarette smoking was associated with not only the development of high-risk plaque but also the increased value of cIMT in the subgroup over 60 years old, whereas only the rate of high-risk plaque was higher in smokers than never smokers in the subgroup under 60 years old.

Carotid plaque and smoking

Conclusion

The development of high-risk carotid artery plaque may precede thickening of cIMT in cigarette smokers, suggesting that the novel insight for the pathological mechanism underlying cardiovascular events and cigarette smoking.

Scintillator-based transverse proton beam profiler for laser-plasma ion sources

A high repetition rate scintillator-based transverse beam profile diagnostic for laser-plasma accelerated proton beams has been designed and commissioned. The proton beam profiler uses differential filtering to provide coarse energy resolution and a flexible design to allow optimisation for expected beam energy range and trade-off between spatial and energy resolution depending on the application. A plastic scintillator detector, imaged with a standard 12-bit scientific camera, allows data to be taken at a high repetition rate. An algorithm encompassing the scintillator non-linearity is described to estimate the proton spectrum at different spatial locations.

Multi-charged heavy ion acceleration from the ultra-intense short pulse laser system interacting with the metal target

Experimental demonstration of multi-charged heavy ion acceleration from the interaction between the ultra-intense short pulse laser system and the metal target is presented. Al ions are accelerated up to 12 MeV/u (324 MeV total energy). To our knowledge, this is far the highest energy ever reported for the case of acceleration of the heavy ions produced by the <10 J laser energy of 200 TW class Ti:sapphire laser system. Adding to that, thanks to the extraordinary high intensity laser field of ∼10(21) W cm(-2), the accelerated ions are almost fully stripped, having high charge to mass ratio (Q/M).

Measurements of electron-induced neutrons as a tool for determination of electron temperature of fast electrons in the task of optimization laser-produced plasma ions acceleration

High intensity laser-plasma interaction has attracted considerable interest for a number of years. The laser-plasma interaction is accompanied by generation of various charged particle beams, such as high-energy proton and ions with high charge to mass ratio (Q/M; same as multi-charged ions). Results of simultaneous novel measurements of electron-induced photonuclear neutrons (photoneutron), which are a diagnostic of the laser-plasma interaction, are proposed to use for optimization of the laser-plasma ion generation. The proposed method is demonstrated by the laser irradiation with the intensity of 1 × 10(21) W/cm(2) on the metal foil target. The photoneutrons are measured by using NE213 liquid scintillation detectors. Heavy-ion signal is registered with the CR-39 track detector simultaneously. The measured signals of the electron-induced photoneutrons are well reproduced by using the Particle and Heavy Ion Transport code System. The results obtained provide useful approach for analyzing the various laser based ion beams.

Insertable pulse cleaning module with a saturable absorber pair and a compensating amplifier for high-intensity ultrashort-pulse lasers

We demonstrate the performance of an efficient insertable pulse cleaning module (IPCM) that uses a saturable absorber (SA) pair with a compensating multi-pass amplifier. IPCM consists of a first SA, a grating compressor, a second SA, a stretcher and a compensating Ti:sapphire amplifier. It is implemented with a conventional chirped pulse amplification (CPA) Ti:sapphire laser system, resulting in a double CPA system architecture, and suppresses the amplified spontaneous emission (ASE) level of the pulse pedestal by about three orders of magnitude while preserving the output pulse energy and repetition-rate of the overall laser system. The duration of recompressed cleaned pulses is comparable to that obtained without the cleaning module. The effectiveness of the cleaning module is confirmed in laser-driven proton acceleration experiments. At the 10(9) W/cm2 pedestal level, the surface structure and electrical resistivity of an insulator target (100 nm silicon nitride) are preserved prior to the arrival of the intense ultrashort pulse.

Quantitative measurement of hard x-ray spectra for high intensity laser produced plasma

X-ray line spectra ranging from 17 to 77 keV were quantitatively measured with a Laue spectrometer, composed of a cylindrically curved crystal and a detector. Either a visible CCD detector coupled with a CsI phosphor screen or an imaging plate can be chosen, depending on the signal intensities and exposure times. The absolute sensitivity of the spectrometer system was calibrated using pre-characterized laser-produced x-ray sources and radioisotopes. The integrated reflectivity for the crystal is in good agreement with predictions by an open code for x-ray diffraction. The energy transfer efficiency from incident laser beams to hot electrons, as the energy transfer agency for specific x-ray line emissions, is derived as a consequence of this work.

Soft-x-ray harmonic comb from relativistic electron spikes

We demonstrate a new high-order harmonic generation mechanism reaching the "water window" spectral region in experiments with multiterawatt femtosecond lasers irradiating gas jets. A few hundred harmonic orders are resolved, giving μJ/sr pulses. Harmonics are collectively emitted by an oscillating electron spike formed at the joint of the boundaries of a cavity and bow wave created by a relativistically self-focusing laser in underdense plasma. The spike sharpness and stability are explained by catastrophe theory. The mechanism is corroborated by particle-in-cell simulations.

Efficient multi-keV x-ray generation from a high-Z target irradiated with a clean ultra-short laser pulse

Kα line emissions from Mo and Ag plates were experimentally studied using clean, ultrahigh-intensity femtosecond laser pulses. The absolute yields of Kα x-rays at 17 keV from Mo and 22 keV from Ag were measured as a function of the laser pulse contrast ratio and irradiation intensity. Significantly enhanced Kα yields were obtained for both Mo and Ag by employing high contrast ratios and irradiances. Conversion efficiencies of 4.28×10⁻⁵/sr for Mo and 4.84×10⁻⁵/sr for Ag, the highest values obtained to date, were demonstrated with contrast ratios in the range 10⁻¹⁰ to 10⁻¹¹.

Enhancement of photon number reflected by the relativistic flying mirror

Laser light reflection by a relativistically moving electron density modulation (flying mirror) in a wake wave generated in a plasma by a high intensity laser pulse is investigated experimentally. A counterpropagating laser pulse is reflected and upshifted in frequency with a multiplication factor of 37-66, corresponding to the extreme ultraviolet wavelength. The demonstrated flying mirror reflectivity (from 3 x 10(-6) to 2 x 10(-5), and from 1.3 x 10(-4) to 0.6 x 10(-3), for the photon number and pulse energy, respectively) is close to the theoretical estimate for the parameters of the experiment.

Electron optical injection with head-on and countercrossing colliding laser pulses

A high stability electron bunch is generated by laser wakefield acceleration with the help of a colliding laser pulse. The wakefield is generated by a laser pulse; the second laser pulse collides with the first pulse at 180 degrees and at 135 degrees realizing optical injection of an electron bunch. The electron bunch has high stability and high reproducibility compared with single pulse electron generation. In the case of 180 degrees collision, special measures have been taken to prevent damage. In the case of 135 degrees collision, since the second pulse is countercrossing, it cannot damage the laser system.

Electron acceleration by a nonlinear wakefield generated by ultrashort (23-fs) high-peak-power laser pulses in plasma

We study experimentally the interaction of the shortest at present (23-fs) , relativistically intense (20-TW), tightly focused laser pulses with underdense plasma. MeV electrons constitute a two-temperature distribution due to different plasma wave-breaking processes at a plasma density of 10(20) cm(-3). These two groups of electrons are shown numerically to constitute bunches with very distinctive time durations.

0.85-PW, 33-fs Ti:sapphire laser

We have successfully produced a laser pulse with a peak power of 0.85 PW for a pulse duration of 33 fs in a four-stage Ti:sapphire amplifier chain based on chirped-pulse amplification. To our knowledge this result represents the highest peak power pulses yet produced in any Ti:sapphire chirped-pulse amplification system.

Identification of the catalytic subunit of cAMP-dependent protein kinase from the photosynthetic flagellate, Euglena gracilis Z

A gene named epk2 that encodes the amino acid sequence of a protein kinase was identified from the photosynthetic flagellate, Euglena gracilis Z. Homology search and phylogenetic analysis revealed that the deduced amino acid sequence of epk2 is most similar to that of the catalytic subunit of cAMP-dependent protein kinase (PKA). Northern blot analysis showed that Euglena cells express a 1.4-kb transcript of this gene. When the EPK2 protein was coexpressed with the rat regulatory subunit of PKA in cultured mammalian cells, these two proteins were coimmunoprecipitated. The association of EPK2 and the rat regulatory subunit of PKA was not detected in the cell lysate incubated with cAMP. EPK2 immunoprecipitated from the transfected cells phosphorylated Kemptide, a synthetic peptide substrate for PKA, and the phosphorylation was inhibited by PKI, a PKA-selective protein kinase inhibitor. These results indicate that EPK2 is a PKA homologue in the photosynthetic flagellate, and this is the first evidence for the occurrence of the PKA catalytic subunit in photosynthetic organisms.

Efficient low-energy near-infrared KTiOPO(4) optical parametric converter

We report a widely tunable near-infrared holosteric KTiOPO(4) optical parametric converter featuring a low pump energy threshold and high conversion efficiency. The converter uses two 10-mm-long crystals in a simple optical parametric oscillator amplif ier configuration and is tunable from 750 to 1040 nm for the signal. The pump energy threshold at 920 nm is 0.44 mJ for the 532-nm 8-ns 50-Hz input. The system produces as much as 0.45 mJ of energy at 920 nm with an external pump-to-signal energy conversion efficiency of 27% for pump inputs from just two times the threshold value. The internal pump-to-signal and idler energy conversion efficiency is estimated to be 58%. The low pump energy requirement of this system makes it compatible with small laser-diode-pumped solid-state lasers.

Malignant pleural mesothelioma presenting as achalasia

A 65-year-old man with an occupational history of asbestos exposure developed dysphagia and vomiting. Clinical examinations at onset revealed a dilated esophagus with smooth narrowing at the gastroesophageal junction and no apparent tumor in and around the esophagus. Achalasia was suspected. Dysphagia progressed gradually and examinations performed three months after the onset disclosed a tumor in the pleural and the peritoneal cavities. At laparotomy, the tumor extended from the pleural cavity into the peritoneal cavity. Histological examination of the biopsied specimen demonstrated malignant mesothelioma. We report the first case of malignant pleural mesothelioma presenting as achalasia.

Effect of anti-allergic agents on chemotaxis of neutrophils by stimulation of chemotactic factor released from hepatocytes exposed to ethanol

In an attempt to clarify a mechanism of neutrophil infiltration in the liver of alcoholics and possible therapeutic effect of antiallergic agents on accumulation of these cells in the liver, we investigated chemotaxis of neutrophils by stimulation of a chemotactic factor released from rat hepatocytes exposed to ethanol. When hepatocytes were incubated with more than 30 mM ethanol for 24 hr, chemotactic activity for both rat and human neutrophils was demonstrated in the conditioned medium. An enhanced chemotactic activity of the conditioned medium was reduced in the presence of antibody against KC/gro protein, one of the interleukin-8-related cytokines in rodents. Antiallergic agents such as azelastine or ketotifen at a concentration of > 0.01 microM markedly reduced chemotaxis of neutrophils. Prednisolone at a concentration of > 10 microM also reduced chemotaxis of neutrophils. These results suggest that neutrophil accumulation in the liver of human alcoholics could be induced by a chemotactic factor produced by the ethanol-treated hepatocytes and that antiallergic agents could be effective against the extent of alcoholic hepatitis by reducing chemotaxis of neutrophils.

Modulation of ischemia-reperfusion-induced hepatic injury by Kupffer cells

To elucidate the role of Kupffer cells in ischemia-reperfusion-induced hepatic injury, hepatic injury induced by ischemia-reperfusion was analyzed after modulation of Kupffer cell function. Ischemia of the liver was performed by occlusion of both the portal vein and hepatic artery, which enter into the left lateral and median lobes of the liver. Blood flow in the ischemic lobe was reduced, in contrast to an increased blood flow in the nonischemic lobe during occlusion of the veins. Although hepatocyte damage was not demonstrated by ischemia for < 60 min, hepatic injury was found after reperfusion of the liver, and activation of Kupffer cells was morphologically demonstrated by electron microscopies. Suppression of Kupffer cells, induced by previous administration of gadolinium chloride or latex particles, reduced the grade of hepatic injury induced by ischemia-reperfusion. On the other hand, stimulation of Kupffer cell phagocytosis, induced by administration of latex particles at the time of reperfusion, aggravated the ischemia-reperfusion-induced hepatotoxicity, which was then reduced by simultaneous administration of superoxide dismutase. Kupffer cells, isolated from the rats treated with the ischemia-reperfusion procedure, have been found to release increased amounts of oxygen radical intermediates. These results suggest that hepatic injury induced by ischemia-reperfusion is modulated by the function of Kupffer cells and that superoxide anion released from Kupffer cells could play an important role in ischemia-reperfusion hepatic injury.

Enzyme-linked immunosorbent assay of colostral IgG transported into lymph and plasma in neonatal pigs

Amounts of colostral proteins in lymph and plasma were estimated by an enzyme-linked immunosorbent assay (ELISA) after infusion of bovine colostrum into the duodenal lumen in nonsuckling neonatal pigs. The rate of immunoglobulin (Ig) G transport in lymph of the thoracic duct reached the maximal level (4.7 +/- 1.3 mg.15 min-1.kg body wt-1) within 3 h after the duodenal infusion. The rate of small protein (SP) transport more slowly increased than that of IgG. On the contrary, casein remained in the much lower level in lymph. IgG concentration in plasma increased gradually and reached a plateau level (2.5 +/- 0.9 g/l) 5 h after the infusion, but the levels of SP and casein were slowly and slightly increased in plasma. The IgG-to-casein and SP-to-casein ratios in lymph and plasma were 161:15:1 and 128:12:1 4 h after the infusion, respectively, and much higher than the value in the colostrum (IgG/SP/casein = 15:4:1). These results indicate 1) that IgG transported via lymph flow after absorption through the small intestine is faster than that via blood flow, 2) that the concentration of absorbed IgG is higher than that of absorbed SP and much higher than the concentration of absorbed casein both in the lymph and plasma, and 3) that total amount of colostral protein transported via blood flow is larger than that transported via lymph flow.

Generation of chemotactic factor by hepatocytes isolated from chronically ethanol-fed rats

In an attempt to clarify a mechanism of polymorphonuclear cell and/or macrophage infiltration in alcoholic liver disease, we investigated a novel chemotactic and activating factor generated by rat hepatocytes isolated from the chronically ethanol-fed rats. Hepatocytes and hepatic macrophages were isolated from rat liver by perfusion and digestion with collagenase and subsequently by differential centrifugation on a metrizamide gradient. Rat polymorphonuclear cells were prepared from blood by the dextran sedimentation and Hypaque-Ficoll technique. Chemotactic activity was measured as migration of polymorphonuclear cells or hepatic macrophages using a chemotactic chamber. When hepatocytes isolated from the ethanol-fed rats were cultured in vitro, chemotactic activity for rat polymorphonuclear cells and hepatic macrophages was demonstrated in the culture supernatant. Inhibitors of transcription and protein synthesis reduced generation of chemotactic factor from these hepatocytes. Chemotactic activity of the conditioned medium was reduced after trypsin (0.25%, 37 degrees C, 30 min) or heat (56 degrees C, 30 min) treatment. The chemotactic activity was eluted at molecular weights of 20-25 kDa and 40-45 kDa following Sephadex G-150 chromatography. Superoxide anion production by polymorphonuclear cells and hepatic macrophages under the stimulation of phorbolmyristate acetate was enhanced in the presence of this chemotactic factor. This chemotactic factor may contribute to the pathogenesis of alcoholic liver disease.

Mechanism of accumulation of macrophages in galactosamine-induced liver injury: effect of lipoxygenase inhibitors on chemotaxis of spleen cells

In an attempt to clarify a mechanism of macrophage infiltration in galactosamine-induced hepatic injury, we investigated chemotactic factor(s) generated by murine hepatocytes exposed to galactosamine. Hepatocytes, isolated from murine liver by perfusion and digestion with collagenase, were incubated with galactosamine. Conditioned medium was collected 24 h later and chemotaxis of murine spleen cells was measured by stimulation of the conditioned medium using a modified Boyden chamber. Chemotactic activity was demonstrated in the conditioned medium of hepatocytes exposed to more than 3 mM galactosamine. Chemotactic activity of the conditioned medium was not reduced after freeze-thawing, and found to be dialyzable (molecular weight < 12,000). Trypsin (0.25%, 37 degrees C, 30 min) or heat (56 degrees C, 30 min) treatment reduced chemotactic activity of the conditioned medium. Furthermore, chemotaxis of spleen cells was decreased in the presence of lipoxygenase inhibitors (azelastine, ketotifen). These results suggest that accumulation of macrophages in the liver could be mediated by chemotactic factor produced by the galactosamine-treated hepatocytes, and that this mechanism may contribute to the pathogenesis of hepatic injury induced by galactosamine.

Analysis of colostral proteins in calf serum by enzyme-linked immunosorbent assay

Enzyme-linked immunosorbent assay method was improved to monitor the concentrations of colostral proteins in the range of 10 to 10(3) ng/ml in calf serum. Colostral proteins were purified from fat-free colostrum, and antibodies against them were prepared from the rabbit anti-colostrum protein sera. Concentration of each protein was determined by enzyme-linked immunosorbent assay without interference by calf serum proteins in a mixture of colostrum and precolostral calf serum. Changes in the colostral protein concentrations in the sera of five postcolostral calves were monitored by enzyme-linked immunosorbent assay. After feeding colostrum to the neonatal calf, serum IgG concentration increased rapidly within 16 h to 8.1 to 36.8 mg/ml and gradually declined until 3 d to the steady levels, 4.7 to 23.6 mg/ml. The concentrations of casein and P2 (colostral small proteins, which were eluted at the second peak in Sephadex G-100 gel filtration) also increased more rapidly within 16 h to 9.6 to 264.0 micrograms/ml and 31.5 to 1600 micrograms/ml, respectively, and steeply decreased to near the detection limit on 3 d after feeding. These results indicate that enzyme-linked immunosorbent assay is useful to measure and monitor the absorbed colostral proteins and also to survey calves receiving and not receiving colostrum.

Oxygen-derived free radical generating capacity of polymorphonuclear cells in patients with ulcerative colitis

Oxygen-derived free radical generating capacity of polymorphonuclear cells in 27 patients with ulcerative colitis, 10 with acute bacterial diarrhea and 20 healthy volunteers, was measured by the luminol-dependent chemiluminescence method by stimulation of formyl-methionyl-leucyl-phenylalanine. Oxidative free radical generating capacity of polymorphonuclear cells in patients with active ulcerative colitis was markedly enhanced as compared with control (p less than 0.01), while this enhanced free radical production by the cells was not detected at remission stage. Serial analyses revealed that oxidative free radical production by the cells in patients with ulcerative colitis was markedly enhanced with clinical deterioration of the disease, but it returned to normal level with an improvement of clinical features. These results suggest that the increased oxidative free radical production by polymorphonuclear cells could be related to the pathogenesis or aggravation of ulcerative colitis.

Postnatal development of biliary and pancreatic exocrine secretion in piglets

1. The secretory responses of bile and exocrine pancreas were studied in various aged piglets. 2. At 3 days old the bile and exocrine pancreas could be reacted by various stimulations. The response by secretin was the same as that in the 28 day old. 3. Protein concentration in pancreatic juice by CCK-8 increased steeply after 6 days old, but the ratio of amylase to protein rose abruptly at 28 days old. 4. These findings indicate that (1) the secretory capacity of bile and pancreatic juice developed predominantly at an early period of postnatal life; (2) the formation of bile acids and pancreatic digestive enzymes developed gradually during the suckling period.