A Case of Recurrent Infective Endocarditis Caused by Streptococcus Agalactiae.

A 53-year-old man was admitted to hospital with a high fever and shivering. He had undergone aortic valve replacement 4 years previously due to infective endocarditis caused by Streptococcus agalactiae. 18F-fluorodeoxyglucose positron emission tomography/CT (18F-FDG PET/CT) showed increased uptake in the tissue surrounding the prosthetic valve. S. agalactiae was detected in blood cultures after admission. We made a diagnosis of prosthetic valve endocarditis due to an S. agalactiae infection relapse. After 6 weeks of antibacterial treatment, the inflammatory findings successfully improved. However, reexamination with 18F-FDG PET/CT suggested the possibility of persistent prosthetic valve infection. Therefore, we decided to continue the oral antibiotic treatment after discharge.

Albumin-to-globulin ratio predicts clinical outcomes of heart failure with preserved ejection fraction in women.

Despite advances in medicine, heart failure with preserved ejection fraction (HFpEF) remains an increasing health concern associated with a high mortality rate. Research has shown sex-based differences in the clinical characteristics of patients with HF; however, definitive biomarkers for poor clinical outcomes of HFpEF in women are unavailable. We focused on the albumin-to-globulin ratio (AGR), a biomarker for malnutrition and inflammation and investigated its usefulness as a predictor of clinical outcomes of HFpEF in women. We measured the AGR in consecutive 224 women with HFpEF and 249 men with HFpEF. There were 69 cardiac events in women with HFpEF and 69 cardiac events in men with HFpEF during the follow-up period. The AGR decreased with advancing New York Heart Association functional class in women with HFpEF. Patients were categorized into three groups based on AGR tertiles. Kaplan-Meier analysis showed that among the three groups, the risk for cardiac events and HF-associated rehospitalizations was the highest in the lowest tertile in women with HFpEF. Univariate and multivariate Cox proportional hazard regression analyses showed that after adjustment for confounding risk factors, the AGR was an independent predictor of cardiac events and HF-associated rehospitalizations in women with HFpEF, but not in men with HFpEF. The addition of AGR to the risk factors significantly improved the net reclassification and integrated discrimination indices in women with HFpEF. This is the first study that highlights the significant association between the AGR and the severity and clinical outcomes of HFpEF in women. Addition of AGR to the risk factors improved its prognostic value for clinical outcomes, which indicates that this variable may serve as a useful clinical biomarker for HFpEF in women.

Association of Nephronophthisis 4 genetic variation with cardiorenal syndrome and cardiovascular events in Japanese general population: the Yamagata (Takahata) study.

BACKGROUND: Nephronophthisis (NPHP) 4 gene encoding nephrocystin-4, which contributes to end-stage renal disease in children and young adults, is involved in the development of the heart and kidneys. Cardiorenal syndrome (CRS), which consists of bidirectional dysfunction of the heart and kidneys, is a risk factor for cardiovascular events. Single-nucleotide polymorphisms (SNPs) within the NPHP4 gene are reportedly associated with kidney function, even in adults. However, the association of NPHP4 gene variability with CRS and cardiovascular events remains unknown. METHODS AND RESULTS: This prospective cohort study included 2946 subjects who participated in a community-based health study with a 16-year follow-up period. We genotyped 11 SNPs within the NPHP4 gene whose minor allele frequency was greater than 0.1 in the Japanese population. The SNP rs12058375 was significantly associated with CRS and cardiovascular events. Multivariate logistic analysis demonstrated a significant association between the homozygous A-allele of rs12058375 with the presence of CRS. Haplotype analysis identified the haplotype with the A-allele of rs12058375 as an increased susceptibility factor for CRS. Kaplan-Meier analysis demonstrated that homozygous A-allele carriers of rs12058375 had the greatest risk of developing cardiovascular events among the NPHP4 variants. Multivariate Cox proportional hazard regression analysis revealed that the homozygous A-allele and heterozygous carriers of rs12058375 were associated with cardiovascular events after adjusting for confounding factors. The net reclassification index and integrated discrimination index were significantly improved by the addition of rs12058375 as a cardiovascular risk factor. CONCLUSION: Genetic variations in the NPHP4 gene were associated with CRS and cardiovascular events in the general population, suggesting that it may facilitate the early identification of high-risk subjects with CRS and cardiovascular events.

Effect of Oxygen Mole Fraction on Static Properties of Pressure-Sensitive Paint.

The effects of the oxygen mole fraction on the static properties of pressure-sensitive paint (PSP) were investigated. Sample coupon tests using a calibration chamber were conducted for poly(hexafluoroisopropyl methacrylate)-based PSP (PHFIPM-PSP), polymer/ceramic PSP (PC-PSP), and anodized aluminum PSP (AA-PSP). The oxygen mole fraction was set to 0.1-100%, and the ambient pressure (Pref) was set to 0.5-140 kPa. Localized Stern-Volmer coefficient Blocal increased and then decreased with increasing oxygen mole fraction. Although Blocal depends on both ambient pressure and the oxygen mole fraction, its effect can be characterized as a function of the partial pressure of oxygen. For AA-PSP and PHFIPM-PSP, which are low-pressure- and relatively low-pressure-type PSPs, respectively, Blocal peaks at PO2ref<12 kPa. In contrast, for PC-PSP, which is an atmospheric-pressure-type PSP in the investigated range, Blocal does not have a peak. Blocal has a peak at a relatively high partial pressure of oxygen due to the oxygen permeability of the polymer used in the binder. The peak of SPR, which is the emission intensity change with respect to normalized pressure fluctuation, appears at a lower partial pressure of oxygen than that of Blocal. This is because the intensity of PSP becomes quite low at a high partial pressure of oxygen even if Blocal is high. Hence, the optimal oxygen mole fraction depends on the type of PSP and the ambient pressure range of the experiment. This optimal value can be found on the basis of the partial pressure of oxygen.

Effects of Thylakoid-Rich Spinach Extract on the Pharmacokinetics of Drugs in Rats.

Thylakoid-rich spinach extract is being used as dietary weight-loss supplements in Japan. A recent rat study has suggested that intake of thylakoid-rich spinach extract with dietary oil inhibits dietary fat absorption via binding to bile acids, which promotes excretion of bile acids in feces. While, we confirmed that a serving size of thylakoid-rich spinach extract contains a large amount of calcium (130 mg/5 g). Therefore, using rats, we evaluated whether one-time ingestion of thylakoid-rich spinach extract affects the gastrointestinal absorption of water-insoluble drugs, such as griseofulvin (GF) and indomethacin (IM), or ciprofloxacin (CPFX) that chelate with polyvalent metal cations. Pretreatment of the rats with thylakoid-rich spinach extract (100 or 300 mg/kg) for 15 min prior to oral administration of GF (50 mg/kg) or IM (10 mg/kg) did not significantly alter the pharmacokinetic properties of either drug. Meanwhile, co-administration of thylakoid-rich spinach extract (500 mg/kg) and CPFX (20 mg/kg) significantly reduced the peak plasma concentration and the area under the plasma concentration-time curve of CPFX to 25 and 40%, respectively in rats. In vitro studies demonstrated that when a mixture of thylakoid-rich spinach extract and CPFX was centrifuged, there was a significant reduction in the supernatant concentration of CPFX relative to the control. When the experiment was repeated in the presence of ethylenediaminetetraacetic acid, the concentration of CPFX was unchanged. These results suggest that the intake of thylakoid-rich spinach extract may reduce the absorption of drugs that form a chelate with polyvalent metal cations, such as CPFX.

Development of an Immunochromatography Assay (QuickNavi-Ebola) to Detect Multiple Species of Ebolaviruses.

The latest outbreak of Ebola virus disease (EVD) in West Africa has highlighted the urgent need for the development of rapid and reliable diagnostic assays. We used monoclonal antibodies specific to the ebolavirus nucleoprotein to develop an immunochromatography (IC) assay (QuickNavi-Ebola) for rapid diagnosis of EVD. The IC assay was first evaluated with tissue culture supernatants of infected Vero E6 cells and found to be capable of detecting 103-104 focus-forming units/mL of ebolaviruses. Using serum samples from experimentally infected nonhuman primates, we confirmed that the assay could detect the viral antigen shortly after disease onset. It was also noted that multiple species of ebolaviruses could be detected by the IC assay. Owing to the simplicity of the assay procedure and absence of requirements for special equipment and training, QuickNavi-Ebola is expected to be a useful tool for rapid diagnosis of EVD.

1,4-Dioxane degradation potential of members of the genera Pseudonocardia and Rhodococcus.

In recent years, several strains capable of degrading 1,4-dioxane have been isolated from the genera Pseudonocardia and Rhodococcus. This study was conducted to evaluate the 1,4-dioxane degradation potential of phylogenetically diverse strains in these genera. The abilities to degrade 1,4-dioxane as a sole carbon and energy source and co-metabolically with tetrahydrofuran (THF) were evaluated for 13 Pseudonocardia and 12 Rhodococcus species. Pseudonocardia dioxanivorans JCM 13855T, which is a 1,4-dioxane degrading bacterium also known as P. dioxanivorans CB1190, and Rhodococcus aetherivorans JCM 14343T could degrade 1,4-dioxane as the sole carbon and energy source. In addition to these two strains, ten Pseudonocardia strains could degrade THF, but no Rhodococcus strains could degrade THF. Of the ten Pseudonocardia strains, Pseudonocardia acacia JCM 16707T and Pseudonocardia asaccharolytica JCM 10410T degraded 1,4-dioxane co-metabolically with THF. These results indicated that 1,4-dioxane degradation potential, including degradation for growth and by co-metabolism with THF, is possessed by selected strains of Pseudonocardia and Rhodococcus, although THF degradation potential appeared to be widely distributed in Pseudonocardia. Analysis of soluble di-iron monooxygenase (SDIMO) α-subunit genes in THF and/or 1,4-dioxane degrading strains revealed that not only THF and 1,4-dioxane monooxygenases but also propane monooxygenase-like SDIMOs can be involved in 1,4-dioxane degradation.

[Development of norovirus rapid detection kit "QuickNavi™-Norovirus2"].

We have evaluated our new Norovirus rapid detection kit "QuickNavi™-Norovirus2" (Denka Seiken Co., Ltd.). The kit is based on Immunochromatographic method using colored latex particles. In addition to simple preparations giving quick (15 min) results, our newly developed kit enables specimen collection directly from rectum and can also be used with neonatal stool samples, both of which cannot be used with the current version of the kit, "QuickNavi™-Norovirus." Clinical study (stool samples, n=172) shows sensitivity, specificity and accuracy of the test compared to RT-PCR are 92.0%, 98.3%, and 94.2%, respectively. The result also showed good correlation with QuickNavi™-Norovirus. In this study, the new Norovirus rapid detection kit has shown sufficient sensitivity and specificity. Their performance, simple preparation enabling rectal swab samples, and quick results can be useful for day to day clinical practice when diagnosing Norovirus infection.

Total body fluid is the factor that affects the pharmacokinetics of tolvaptan, and its efficacy, in acute worsening heart failure patients.

The optimal starting dose of tolvaptan to effectively improve fluid retention in patients with heart failure (HF) is unknown. This study explored the factors affecting the pharmacokinetics (PKs) and pharmacodynamics of tolvaptan in patients with decompensated HF. We prospectively enrolled patients who were slated to receive tolvaptan because of volume overload associated with chronic HF. Blood samples were collected to measure tolvaptan concentrations before and 4, 8, 12-15, 24, and 144 h after administration. Additionally, demographic parameters, coadministered drugs, and body fluid composition were evaluated. Multiple regression analysis to detect PK parameters for the prediction of body weight (BW) loss at day 7 after the initiation of tolvaptan treatment and PK analysis to explore the factors affecting the PKs of tolvaptan were performed. In total, 165 blood samples were obtained from 37 patients. The predictors of weight loss on day 7 were area under the curve (AUC0-∞ ) of tolvaptan. PK analysis of the data revealed a strong correlation between CL/F and Vd/F, but no correlation between CL/F and kel (r = .95 and .06, respectively). A significant correlation was observed between total body fluid and Vd/F, and this correlation remained statistically significant even after adjusting for BW (r = .49, p < .05). Fat was also significantly correlated with Vd/F before adjusting for BW, on the other the correlation disappeared after adjusting BW. The optimal dose of tolvaptan based on total body fluid levels in individual patients could result in the alleviation of fluid retention in patients with HF.

Recurrent Takotsubo Syndrome Presenting with Different Ballooning Patterns and Electrocardiographic Abnormalities.

A 73-year-old woman presented with takotsubo syndrome with apical ballooning patterns after quarreling with her husband. Two years later, she was admitted to the hospital with chest pain after experiencing the same emotional stress. Her electrocardiogram showed different abnormalities compared to the previous event, and her left ventriculogram demonstrated takotsubo syndrome with mid-ventricular ballooning patterns. Recurrence of takotsubo syndrome with different ballooning patterns is rare. We herein report our experience with a patient who developed recurrent takotsubo syndrome with various ballooning patterns and different electrocardiographic abnormalities along with a literature review.

Amiodarone-induced syndrome of inappropriate antidiuresis with hepatic transaminitis.

A 72-year-old woman with hypertrophic cardiomyopathy was admitted to the hospital after an appropriate implantable cardioverter-defibrillator shock for ventricular fibrillation. She was discharged after the addition of amiodarone. Eight months after discharge, she was admitted to the hospital with a sign of somnolence. She had low levels of serum sodium and plasma osmolality, as well as hepatic transaminitis. She underwent a computed tomography scan, which detected high liver density. Amiodarone-induced syndrome of inappropriate antidiuresis with hepatic transaminitis was diagnosed, and amiodarone was discontinued. After discharge, her hepatic transaminitis improved, and there was no recurrence of hyponatremia with a sign of somnolence. Amiodarone is an important drug used to treat ventricular arrhythmias. However, it has a variety of adverse effects. Syndrome of inappropriate antidiuresis is a rare complication of amiodarone. If hyponatremia occurs after starting amiodarone, this complication should be considered. Learning objective: Amiodarone is an important drug used to treat ventricular arrhythmias, such as ventricular tachycardia and ventricular fibrillation. However, amiodarone has a variety of adverse effects. Syndrome of inappropriate antidiuresis is a rare complication of amiodarone. If hyponatremia occurs after starting amiodarone, this complication should be considered.

Prognostic impact of plasma xanthine oxidoreductase activity in patients with heart failure with atrial fibrillation.

BACKGROUND: Xanthine oxidoreductase (XOR) is a rate-limiting enzyme for uric acid (UA) production and plays an important role in generating reactive oxygen species (ROS). Overproduction of ROS is reported to contribute to the pathophysiology of atrial fibrillation (AF), however, the prognostic impact of plasma XOR activity in patients with heart failure (HF) with AF is undetermined. METHODS: We measured plasma XOR activity in 475 HF patients, including those with sinus rhythm (HF-SR, n = 211), and those with AF (HF-AF, n = 264). The type of AF included paroxysmal (n = 128) and persistent (n = 136) AF. All patients were prospectively followed up for a median period of 804 days. RESULTS: HF-AF patients had significantly higher plasma XOR activity and serum UA levels compared with HF-SR patients. Both plasma XOR activity and serum UA levels were higher in patients with persistent AF than in those with SR and with paroxysmal AF. Multivariate linear regression analysis showed that persistent AF was independently associated with increased XOR activity. During the follow-up period, there were 79 major adverse cardiovascular events (MACEs). HF-AF patients with MACEs had higher plasma XOR activity compared with those without MACEs, while there were no significant differences in serum UA levels. Multivariate Cox proportional analysis showed that high XOR activity was an independent risk factor for MACEs after adjustment for confounding factors. Kaplan-Meier analysis revealed that the high XOR activity group had a higher risk of MACEs than the low XOR activity group. The prediction model was significantly improved by the addition of XOR activity to the basic predictors. CONCLUSIONS: HF-AF patients had significantly higher plasma XOR activity compared with HF-SR patients. Plasma XOR activity proved to be a reliable indicator for MACEs in HF-AF patients.

Growth Differentiation Factor-15 and Clinical Outcomes in Japanese Patients With Ischemic Heart Disease.

Background: Despite a reduction in the rate of thrombotic events, ischemic heart disease (IHD) remains a key medical problem associated with high major bleeding and mortality in Asian patients with IHD. Growth differentiation factor (GDF)-15, a stress-response cytokine belonging to the transforming growth factor beta superfamily, is reportedly associated with poor clinical outcomes in Western patients with IHD. However, the clinical significance of GDF-15 in Asian patients with IHD has not yet been fully elucidated. Objectives: The aim of the present study was to examine the impact of serum GDF-15 on clinical outcomes in Japanese patients with IHD. Methods: Serum GDF-15 levels were evaluated in 632 consecutive patients with IHD. All patients were followed up for a median period of 2.8 years. The primary endpoint was the all-cause mortality rate. Secondary endpoints were major adverse cardiovascular events (MACE), heart failure (HF)-related rehospitalization, bleeding, and thrombotic events. Results: Serum GDF-15 levels were elevated in acute coronary syndrome, severe coronary artery disease, and the major Japanese version of the high bleeding risk criteria. Multivariate Cox proportional hazards regression analysis demonstrated that GDF-15 was an independent predictor of all-cause mortality, MACE, HF-related rehospitalizations, and bleeding events after adjusting for confounding risk factors but not for thrombotic events. Adding GDF-15 to risk factors significantly improved the net reclassification index and integrated discrimination improvement for all-cause deaths, MACE, HF-related rehospitalization, and bleeding events. Conclusions: Serum GDF-15 could be a feasible marker for major bleeding and adverse clinical outcomes in Japanese patients with IHD.

Renal tubular damage and clinical outcome in heart failure with preserved ejection fraction and chronic kidney disease.

AIMS: Despite advances in heart failure (HF) treatment, HF with preserved ejection fraction (HFpEF) remains a health problem with a high mortality rate. HFpEF is composed of diverse phenogroups, of which patients with concomitant renal impairment have worse outcomes. Renal tubular damage (RTD) is associated with the development of HF and chronic kidney disease (CKD). However, the impact of RTD on HF progression in patients with HFpEF and CKD remains unclear. The aim of the present study was to examine whether RTD could predict HF-related events in patients with HFpEF and CKD. METHODS AND RESULTS: We measured RTD markers, such as urinary ß2 -microglobulin to creatinine ratio (UBCR) and N-acetyl-ß-d-glucosamidase (NAG) level, in 319 consecutive patients with HFpEF and CKD who were hospitalized for acute HF (49% females, mean age 76 ± 12). Based on previous reports, high UBCR and high NAG levels were defined as UBCR ≥300 µg/gCr and NAG >14.2 U/gCr, respectively. There were 91 HF-related events, defined as HF hospitalizations or HF deaths, during the median follow-up period of 5.2 years. The prevalence of high UBCR increased with advancing New York Heart Association functional class and albuminuria. Kaplan-Meier analysis demonstrated that patients with high UBCR had more HF-related events than those with normal or low UBCR. Multivariate Cox proportional hazards regression analyses demonstrated that high UBCR, but not high NAG level, was an independent predictor of HF-related events after adjusting for confounding risk factors in patients with HFpEF and CKD (hazard ratio, 2.60; 95% confidence interval, 1.52-4.72; P = 0.0009). UBCR significantly improved the C-statistic, with a significant net reclassification index and integrated discrimination improvement (0.738 vs. 0.684; P = 0.0244). CONCLUSION: RTD, as assessed by a high UBCR, was associated with the severity and clinical outcomes of HFpEF and CKD, indicating that it could be a feasible marker for HF progression.

Slow-light-based variable symbol-rate silicon photonics DQPSK receiver.

We report a silicon DQPSK receiver whose symbol rate can be varied by a tunable one-bit delay line including an all-pass micro-ring slow-light device. It also consists of Si-wire waveguides with spot-size converters, optimized splitters/couplers, heater-controlled Mach-Zehnder attenuators and phase shifters, 90° hybrid with a low-loss crossing and balanced Ge photodiodes, all of which are fabricated by using CMOS-compatible process. Demodulation was confirmed at symbol-rates of 7.4 - 9.0 Gbaud, corresponding to bit-rates of 14.8 - 18.0 Gb/s.

Effects of Nitric Oxide Synthase 3 Gene Polymorphisms on Cardiovascular Events in a General Japanese Population　- The Yamagata (Takahata) Study.

Background: Single nucleotide polymorphisms (SNPs) in nitric oxide synthase 3 (NOS3) are associated with cardiovascular risk factors. However, it is not clear whether the NOS3 SNP is a genetic risk factor for cardiovascular diseases. Methods and Results: This prospective cohort study included 2,726 subjects aged ≥40 years who participated in a community-based health checkup. We genotyped 639 SNPs, including 2 NOS3 SNPs (rs1799983 and rs1808593). All subjects were monitored prospectively over a median follow-up period of 16.0 years, with the endpoint being cardiovascular events, including cardiovascular death and/or non-fatal myocardial infarction. Kaplan-Meier analysis demonstrated that both rs1799983 GT/TT and rs1808593 GG carriers had a higher risk of the endpoint than non-carriers. Univariate and multivariate Cox proportional hazard regression analyses revealed that both rs1799983 GT/TT and rs1808593 GG were independently associated with cardiovascular events after adjusting for confounding risk factors. The net reclassification index and integrated discrimination index were significantly improved by the addition of NOS3 SNPs as cardiovascular risk factors. Conclusions: NOS3 gene polymorphisms could be genetic risk factors for cardiovascular events in the general Japanese population, and could be used to facilitate the early identification of individuals at high risk of cardiovascular events.

Association of malnutrition with renal dysfunction and clinical outcome in patients with heart failure.

Malnutrition, glomerular damage (GD), and renal tubular damage (RTD) are common morbidities associated with poor clinical outcomes in heart failure (HF) patients. However, the association between malnutrition and renal dysfunction and its impact on clinical outcomes in HF patients have not yet been fully elucidated. We assessed the nutritional status and renal function of 1061 consecutive HF patients. Malnutrition, GD, and RTD were defined as a controlling nutritional status (CONUT) score of ≥ 5, reduced eGFR or microalbuminuria, and levels of N-acetyl-beta-D-glucosamidase of > 14.2 U/gCr according to previous reports, respectively. Patients with RTD had a higher CONUT score and a lower prognostic nutritional index and geriatric nutritional risk index than those without. Multivariate logistic analysis demonstrated that RTD, but not GD, was significantly associated with malnutrition. There were 360 cardiac events during the median follow-up period of 688 days. Multivariate Cox proportional hazard regression analysis demonstrated that comorbid malnutrition and renal dysfunction, rather than simple malnutrition, were significantly associated with cardiac events in HF patients. We found a close relationship between malnutrition and renal dysfunction in HF patients. Comorbid malnutrition and renal dysfunction were risk factors for cardiac events in HF patients, suggesting the importance of managing and treating these.

Sensitivity of transbronchial lung cryobiopsy in the diagnosis of different interstitial lung diseases.

The accuracy of transbronchial lung cryobiopsy (TBLC) in each disease for pathological and multidisciplinary discussion (MDD) diagnosis is not yet established. METHOD: We investigated 431 patients who were classified by MDD diagnosis and were grouped into the disease categories. For each category or disease, we used TBLC samples to calculate the sensitivities of the pathological diagnosis compared with MDD diagnoses. Further, we compared these sensitivities to pathological diagnoses with all clinical/radiological information. RESULT: The sensitivity for diagnosing idiopathic interstitial pneumonia (IIPs) with TBLC was higher than connective tissue disease associated ILD (CTD-ILD). Idiopathic nonspecific interstitial pneumonia (iNSIP), fibrotic hypersensitivity pneumonitis, and some CTD-ILDs were diagnosed with lower sensitivities compared to IPF. The sensitivity of pathological diagnosis with all clinical/radiological information in IPF was higher than in iNSIP, but not significantly different from other diseases. The overall sensitivity of the pathological diagnosis with clinical/radiological information was 69.0%, significantly higher than without clinical/radiological information. CONCLUSION: The sensitivity of pathological diagnosis with TBLC was low for some diseases except IPF. The addition of all clinical/radiological information increased the sensitivity of pathology diagnosis by TBLC, which was no less sensitive than IPF for all diseases except iNSIP.

Stopping of light by the dynamic tuning of photonic crystal slow light device.

We propose a simple technique of stopping light pulses using a slow-light device based on photonic crystal coupled waveguide (PCCW). Dynamically tuning the material index chirp in the PCCW adiabatically transforms slow-light pulses into stopped ones. We demonstrate this in finite-difference time-domain simulation assuming ideal and actual tuning of the index chirp. In the ideal case, the group velocity of the almost stopped pulse is reduced to 190 times smaller than that of simple slow light pulse. The smallest limit is affected by the timing error of the tuning between wavelengths. Re-ordering and stopping of a pulse train are possible by optimizing the device length and timing. As a practical tuning method, we discuss carrier effects induced by photo-excitation. Taking into account carrier distribution and free carrier absorption, the actual behaviors of stopped light are estimated. We define and evaluate an effective delay-bandwidth product, which is affected by free carrier absorption.

[Usefulness and safety of propranolol injection into vein for acquisition of coronary multidetector-row computed tomography].

BACKGROUND: A low heart rate (HR), associated with a prolonged slow filling phase (SF), is necessary to obtain a high quality coronary CT at a low radiation dose with conventional 64 multidetector-row computed tomography (MDCT). The purpose of our study was to confirm the safety of injecting propranolol (2-10 mg) into the vein for lowering heart rate in patients requiring MDCT and to document the effect of the drug on HR, PQ and SF. METHOD: Of 1290 consecutive patients who were initially considered for enrollment in the coronary MDCT study, 40 patients with atrial fibrillations, 3 with atrial flutters, and 13 with artificial pacemakers were excluded. Of the remaining 1234 patients (M/F=714/520), 331 had already taken an oral beta-blocker before the CT examination, and were included in the study. In patients with no contraindications, propranolol was aggressively injected (2-10 mg) into the vein to reduce the HR. RESULT: In patients not taking an oral beta blocker, 2 mg propranolol reduced the HR by -10±5 bpm and 10 mg, by -20±7 bpm. However, in patients taking an oral beta-blocker, the decrease in HR by propranolol was minimal (2 mg, -6±4 bpm; 10 mg, -10±6 bpm). Propranolol significantly prolonged the PQ interval (from 169±27 to 179±29 ms, P<0.0001), and SF (from 125±69 to 264±79 ms, P<0.0001). Adverse effects of propranolol injection were observed in only 3 [2 mild hypotension and 1 paroxysmal atrial fibrillation (recovered to sinus rhythm by DC counter shock)] of 3212 patients. All 3 patients became stable after 1 or 2 hours of rest and could return home. CONCLUSION: Propranolol injection was a relatively safe and useful method to reduce HR and prolong SF, necessary for obtaining high quality coronary MDCT with a low radiation dose.