Gastrointestinal bleeding during direct oral anticoagulants therapy in patients with nonvalvular atrial fibrillation and risk of polypharmacy

Although concomitant medications have been raised as a factor affecting hemorrhage during direct oral anticoagulants (DOACs) therapy, details remain unelucidated. This study was conducted to clarify the relationship between concomitant medications with possible pharmacokinetic interactions and number of concomitant medications, and bleeding and embolism in patients with nonvalvular atrial fibrillation on DOACs. The subjects were 1,010 patients prescribed DOACs from a single-center at the Teikyo University Hospital between April 2011 and June 2018. This study was an exploratory analysis and investigated their course between the first prescription and December 2018, including the presence or absence of clinically relevant bleeding, gastrointestinal bleeding, and major cardiovascular and cerebrovascular events. Impacts of medications were evaluated by the general linear model with inverse probability-weighted propensity score. The observation period was 2,272 patient-years. The rate of bleeding was 4.7%/year, gastrointestinal bleeding was 2.8%/year, and major cardiovascular and cerebrovascular events was 2.0%/year. Taking 10 or more oral medications concurrently was a significant risk for gastrointestinal bleeding (hazard ratio, 2.046 [1.188-3.526]; p = 0.010). Nonsteroidal anti-inflammatory drugs (NSAIDs) were the only significant risk for gastrointestinal bleeding. Clinicians should be aware of gastrointestinal bleeding when using DOACs with patients taking more than 10 medications and/or NSAIDs. This article is protected by copyright. All rights reserved.

Clinical factors associated with safety and efficacy in patients receiving direct oral anticoagulants for non-valvular atrial fibrillation

Although patients suffering from atrial fibrillation have increased worldwide, detailed information about factors associated with bleeding during direct oral anticoagulant therapy remains insufficient. We studied 1086 patients for whom direct oral anticoagulants were initiated for non-valvular atrial fibrillation between April 2011 and June 2017. Endpoints were clinically relevant bleeding or major adverse cardiac and cerebrovascular events until the end of December 2018. Incidences of bleeding and thrombosis were 4.5 per 100 person-years and 4.7 per 100 person-years, respectively. Most bleeding events represented gastrointestinal bleeding. Multivariate analysis revealed initiation of anticoagulants at ≥ 85 years old as significantly associated with bleeding, particularly gastrointestinal bleeding, but not major cardiac and cerebrovascular events. Other significant factors included chronic kidney disease, low-dose aspirin and nonsteroidal anti-inflammatory drugs. For gastrointestinal bleeding alone, histories of gastrointestinal bleeding and malignancy also showed positive correlations, in addition to the above-mentioned factors. Clinicians should pay greater attention to the risk of gastrointestinal bleeding when considering prescription of anticoagulants to patients ≥ 85 years old with atrial fibrillation.

Prevalence and Predictors of Atherosclerotic Peripheral Arterial Obstructive Disease in Severe Heart Valve Diseases

Despite witnessing an upsurge in heart valve diseases (HVDs), the correlation between HVDs and atherosclerotic peripheral arterial obstructive disease (PAOD) remains unclear. This study aims to investigate the prevalence and predictors of PAOD in HVDs.In this study, a total of 245 consecutive patients were examined: 153 with severe aortic valve stenosis (AS), 66 with severe primary mitral valve regurgitation (MR), and 26 with severe pure native aortic valve regurgitation (AR). All patients underwent ultrasound scan of the carotid artery to ascertain the presence of internal carotid artery stenosis (ICAS). ICAS was defined as a peak systolic velocity ≥ 125 cm/second and/or ≥ 50% reduction in diameter. In addition, we measured the ankle-brachial index in each leg using a volume plethysmograph. A result of ≤ 0.9 was considered lower extremity artery disease (LEAD).The presence of ICAS was statistically more frequent in patients with severe AS than in patients with severe MR and AR (11.1% versus 1.5% versus 3.8%; P = 0.038). LEAD was present in patients with severe AS (17.6%) and MR (10.6%) but not in patients with severe AR (P = 0.037). The multivariate analysis revealed that the presence of severe AS (OR, 5.6 [1.3-24.9]; P = 0.023) was an independent predictor for ICAS, while history of coronary artery disease (OR, 4.8 [2.2-10.5]; P < 0.001) was an independent predictor for LEAD.The prevalence of PAOD varies depending on each valvular disease. Individual screening should be considered on the basis of atherosclerotic risk factors, especially for patients with severe AS.

Efficacy and safety of transcatheter aortic valve implantation with Edwards SAPIEN 3 and XT in smaller Asian anatomy

We aimed to compare the efficacy and safety of transcatheter aortic valve implantation (TAVI) using Edwards SAPIEN 3 (S3) valve and SAPIEN XT) in smaller anatomy. The new generation S3 TAVI device has been used worldwide; however, its efficacy and safety in smaller Asian anatomy remain unknown. Between February 2014 and March 2017, 166 consecutive patients (S3, 54; XT, 112) were treated with balloon-expandable TAVI in a single center and their outcomes were analyzed. Median patient age was 85 (range: 81-88) years and mean body surface area was 1.41 ± 0.15 m². A 23-mm size valve was used in S3 and XT groups (70 vs. 62%, p = 0.224). The transfemoral approach was more frequently used in the S3 than in the XT group (96 vs. 72%, p < 0.001). Although, the minimal luminal diameter of the femoral artery was smaller in the S3 group (5.9 vs. 6.4 mm, p = 0.001), the rates of major (2 vs. 11%, p = 0.226) and minor (11 vs. 5%, p = 0.107) vascular complications did not increase. The frequency of paravalvular leaks (PVL) ≥ 2 was significantly reduced in the S3 group (11 vs. 61%, p < 0.001); however, pre- (24 vs. 91%, p < 0.001) and post- (4 vs. 19%, p < 0.001) dilatations were less frequently performed. Pacemaker implantation incidence did not increase (4 vs. 5%, p = 1.0) and peak velocity of the transcatheter heart valve was significantly higher in the S3 group (2.3 vs. 2.2 m/s, p = 0.046). Device success was high (89 vs. 93%, p = 0.387) while the 30-day all-cause mortality was low (2 vs. 1%, p = 0.583) in both groups. TAVI with the S3 device was safe and effective, with low incidence of vascular complications and reduced PVL, in smaller body-sized Asians.

Inhibitory Effects of Acyclic Nucleoside Phosphonate Analogues on Hepatitis B Virus DNA Synthesis in HB611 Cells

By using an assay system based on a human hepatoblastoma cell line (HB611) that continuously synthesizes hepatitis B virus (HBV) DNA, 56 acyclic nucleoside phosphonate analogues were examined for their inhibitory effects on HBV DNA synthesis. The following compounds were found to inhibit HBV DNA synthesis at concentrations that were significantly lower than their minimum cytotoxic concentrations; 9-(2-phosphonylmethoxyethyl)adenine (PMEA), 9-(2-phosphonylmethoxyethyl) guanine(PMEG), 9-(2-phosphonylmethoxyethyl) guanine ethyl ester (PMEGEE), 9 - (2 - phosphonylmethoxyethyl) - 1 - deazaadenine (PMEC1A), 9-(2-phosphonylmethoxyethyl)-2,6-diaminopurine (PMEDAP), ( S)-9-(3-hydroxy-2-phosphonylmethoxypropyl)adenine (HPMPA), 9-(3-isopropoxy-2-phosphonylmethoxypropyl)adenine (IPPMPA), 9-( RS)-(2-phosphonylmethoxypropyl)adenine (PMPA) and 9-(3-hydroxy-2-phosphonylmethoxypropyl)-2, 6-diaminopurine (HPMPDAP). The most selective compounds (with indexes greater than 100) were PMEDAP, PMEA, IPPMPA, and PMPA. Acyclic pyrimidine nucleoside phosphonate analogues did not prove markedly selective as anti-HBV agents. Diphosphoryl derivatives of some acyclic purine nucleoside phos-phonates (i.e. PMEA, PMEDAP, HPMPA) were prepared. They proved inhibitory to HBV DNA polymerase but not cellular DNA polymerase α.

Inhibition of Thymidylate Synthetase Activity Induced in Varicella-Zoster Virus Infected Cells by (E)-5-(2-bromovinyl)-2′-deoxyuridine

The authors investigated the effect' of thymidylate synthetase (TS) on the antivariclllazoster virus (VZV) activity of ( E)5-(2-bromovinyl)-2′-deoxyuridine (BVDU). TS catalyses the conversion of deoxyuridylate (dUMP) to thymidylate (dTMP) and is a key enzyme in pyrimidine biosynthesis, providing the only source of dTMP synthesized de novo in mammalian cells. VZV encodes a specialized viral form of TS. TS activity in cells infected with VZV (TIO-VZV and TK−-VZV) increased proportionally with focus formation. From kinetic analysis using the Michaelis-Menten equation, the authors determined a Km value of 6.6μm for dUMP of TS induced in VZV-infected cells and a corresponding value from mock-infected cells of only 2.8μm. BVDU inhibited the induction of TS activity in TK+-VZV-infected cells at concentrations under ×10−3μm, but did not inhibit TS activity of TK−-VZV- or mock-infected cells at concentrations as high as 10μm. Inhibitory activity of BVDU against TS induced in TK+-VZV-infected cells appears to occur when BVDU is phosphorylated to BVDU monophosphate by viral pyrimidine kinase. These results suggest that the selective inhibitory action of BVDU on VZV replication depends on a specific interaction with both viral TK and TS. 5-Bromodeoxyuridine and 5-iododeoxyuridine inhibited TS activities induced in both VZV (TK+, TK−) and mock-infected cells. Other antiherpes compounds [i.e. 1-β-D-arabinofuranosyl- E-5-(2-bromovinyl)uracil, 9- 2-hydroxyethoxymethyl)-guanine, arabinosyladenine, and others] did not inhibit TS activity in VZV-infected cells at concentrations Of 10μm.

Ingenol Derivatives are Highly Potent and Selective Inhibitors of HIV Replication in Vitro

Ingenol 3,5,20-triacetate has recently been identified as a highly potent and selective inhibitor of HIV replication in vitro. To evaluate the potential of ingenol derivatives as anti-HIV agents, several ingenol derivatives have been synthesized and investigated for their anti-HIV activities, structure-activity relationships, and possible mechanisms of action. Among the ingenol derivatives, 13-hydroxyingenol-3-(2,3-dimethylbutanoate)-13-dodecanoate (RD4-2138) proved to be a highly potent and selective inhibitor of HIV replication. Its 50% effective concentration for viral replication in MT-4 cells was 0.07-0.5 nM depending on viral strains, including HIV-2. This concentration was approximately 105-fold lower than its cytotoxic threshold. RD4-2138 was also inhibitory to the syncytium formation induced by cocultivation of Molt-4 cells with Molt-4/IIIB cells (Molt-4 cells chronically infected with HIV-1). Some correlation was observed with the ingenol derivatives between their inhibitory effects on HTLV-IIIB replication and surface CD4 expression in MT-4 cells, suggesting that the mechanism of inhibition is in part attributed to the inhibition of virus adsorption through down-regulation of CD4 molecules in the host cells. However, such correlation was not identified between the inhibition of HTLV-IIIB and the activation of protein kinase C. Thus, they might have a potential as effective anti-HIV agents when toxicity in vivo could be elucidated.

Emerging ST121/agr4 community-associated methicillin-resistant Staphylococcus aureus (MRSA) with strong adhesin and cytolytic activities: trigger for MRSA pneumonia and fatal aspiration pneumonia in an influenza-infected elderly

The pathogenesis of community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) pneumonia in influenza-infected elderly individuals has not yet been elucidated in detail. In the present study, a 92-year-old man infected with influenza developed CA-MRSA pneumonia. His CA-MRSA was an emerging type, originated in ST121/agr4 S. aureus, with diversities of Panton–Valentine leucocidin (PVL)⁻/spat5110/SCCmecV⁺ versus PVL⁺/spat159^(etc.)/SCCmec⁻, but with common virulence potentials of strong adhesin and cytolytic activities. Resistance to erythromycin/clindamycin (inducible-type) and gentamicin was detected. Pneumonia improved with the administration of levofloxacin, but with the subsequent development of fatal aspiration pneumonia. Hence, characteristic CA-MRSA with strong adhesin and cytolytic activities triggered influenza-related sequential complications.

Development of new risk score for pre-test probability of obstructive coronary artery disease based on coronary CT angiography

Existing methods to calculate pre-test probability of obstructive coronary artery disease (CAD) have been established using selected high-risk patients who were referred to conventional coronary angiography. The purpose of this study is to develop and validate our new method for pre-test probability of obstructive CAD using patients who underwent coronary CT angiography (CTA), which could be applicable to a wider range of patient population. Using consecutive 4137 patients with suspected CAD who underwent coronary CTA at our institution, a multivariate logistic regression model including clinical factors as covariates calculated the pre-test probability (K-score) of obstructive CAD determined by coronary CTA. The K-score was compared with the Duke clinical score using the area under the curve (AUC) for the receiver-operating characteristic curve. External validation was performed by an independent sample of 319 patients. The final model included eight significant predictors: age, gender, coronary risk factor (hypertension, diabetes mellitus, dyslipidemia, smoking), history of cerebral infarction, and chest symptom. The AUC of the K-score was significantly greater than that of the Duke clinical score for both derivation (0.736 vs. 0.699) and validation (0.714 vs. 0.688) data sets. Among patients who underwent coronary CTA, newly developed K-score had better pre-test prediction ability of obstructive CAD compared to Duke clinical score in Japanese population.

Impact of combined assessment of coronary artery calcium score, carotid artery plaque score, and brachial-ankle pulse wave velocity for early coronary revascularization in patients with suspected coronary artery disease

Coronary artery calcium score (CACS) measured by multi-detector computed tomography, carotid plaque score (CPS) measured by carotid artery ultrasound, and brachial-ankle pulse wave velocity (baPWV) are noninvasive screening tools for coronary artery disease. The aim of this study was to determine whether the combination of CACS, CPS, and baPWV improves the prognostic value for future cardiac events. CACS, CPS, and baPWV were assessed in 77 patients (mean age, 65 years, 49 males) undergoing invasive coronary angiography. ECG-triggered MSCT was used to assess CACS. CPS was defined as the sum of all plaque heights in bilateral carotid arteries. The highest baPWV was used for analysis. Cardiac events were defined as cardiac death, nonfatal myocardial infarction, or coronary revascularization. Thirty-two cardiac events (41.6%) occurred during follow-up (23.6 ± 20.8 months), consisting of 28 PCIs and 4 CABGs. The best cutoff values of positive CACS, CPS, and baPWV for predicting cardiac events were ≥ 50, ≥ 5, and ≥1.6 m/second, respectively. For the combination of the 3 modalities, the positive test was defined as having at least 1 positive result by each method. The negative predictive value of all 3 modalities combined was better than that of CACS alone. The event-free rate was higher in patients with negative results for all 3 parameters compared with those that were positive (100% versus 44.8%, P < 0.0001). The prognostic value of using combined assessment of CACS, CPS, and baPWV is more effective for predicting cardiac events than CACS alone.

Selective Bronchodilators from 1-(5′-Oxohexyl)xanthines

A series of twenty one 1-(5′-oxohexyl)xanthines substituted with alkyl chains at the N 3 and N 7 positions of the xanthine nucleus were prepared and their relaxant activity in guinea-pig isolated tracheal muscle and positive chronotropic activity in isolated right atrium of guinea-pig were compared. The tracheal relaxant activities were markedly increased with alkyl chain length at the N 3 position, but decreased by the N 7 alkylation. The positive chronotropic activities in the right atrium were increased by introduction of an n-propyl group at the N 3 position but decreased by substitution of longer alkyl chains, and the action on the heart was diminished by N 7 substitution. The activities of compounds on cAMP-phosphodiesterase (PDE) and binding of [3H]8-cyclopentyl-1,3-dipropylxanthine were measured in the homogenate of tracheal muscle and the membrane preparation of cerebral cortex, respectively. No relationship among tracheal muscle relaxant activity, cAMP-PDE inhibitory activity and adenosine antagonism of these xanthines was observed, and other action mechanisms should be considered for their relaxant activities. This study indicated that N 3 alkylation is important for the selectivity for tracheal muscle, while the introduction of long alkyl chains such as n-butyl and n-pentyl groups at the N 3 and N 7 positions diminished the potency for the right atrium in guinea-pigs. 3-n-Pentyl- and 7-methy]-3-n-pentyl-1-(5′-oxohexyl)xanthines showed much higher bronchoselectivity than oxpentifylline and theophylline.

Atomic-scale heterogeneity of a multicomponent bulk metallic glass with excellent glass forming ability

We report the atomic structure of a multicomponent Cu45Zr45Ag10 bulk metallic glass investigated by state-of-the-art experimental and computational techniques. In comparison with a binary Cu50Zr50 metallic glass, Zr-rich interpenetrating clusters centered by paired and stringed Ag atoms and Cu-rich icosahedra are widely observed in the ternary Cu45Zr45Ag10 alloy. The atomic-scale heterogeneity caused by chemical short- and medium-range order is found to play a key role in stabilizing the liquid phase and in improving the glass forming ability of the multicomponent alloy.

Color development of squid skin as affected by oxygen concentrations

Color development of squid skin was controlled by O2 concentration for storage. When stored above 10% O2, the color index (CI) as an index of color development of skin increased in 24 h, and decreased gradually with further storage. The CI profile at 10% O2 was practically identical to that in air. When stored at 0.1% O2, in the presence of N2, the CI increased partly in 6 h and decreased. Morphological observation of chromatophore distinguished the CI increase at 0.1% and 10% O2 by their shape and size distribution. However, the storage of squid at O2 concentration between 2.5% and 7% practically did not change the CI for at least 48 h. ATP content of skin was kept unchanged when the storage atmosphere contained O2 concentration at 2.5% up to 48 h, while the content decreased rapidly with a half decrease in 6 h when stored at 0.1% O2. It was demonstrated clearly that ATP is regenerated in the presence of O2, but the ATP concentration did not determine the CI change during the storage. Exposure to high concentration of O2 might induce a full color development of squid skin.

Coronary artery stent evaluation using a vascular model at 64-detector row CT: comparison between prospective and retrospective ECG-gated axial scans

Objective

We wanted to evaluate the performance of prospective electrocardiogram (ECG)-gated axial scans for assessing coronary stents as compared with retrospective ECG-gated helical scans.

Materials and Methods

As for a vascular model of the coronary artery, a tube of approximately 2.5-mm inner diameter was adopted and as for stents, three (Bx-Velocity, Express2, and Micro Driver) different kinds of stents were inserted into the tube. Both patent and stenotic models of coronary artery were made by instillating different attenuation (396 vs. 79 Hounsfield unit [HU]) of contrast medium within the tube in tube model. The models were scanned with two types of scan methods with a simulated ECG of 60 beats per minute and using display field of views (FOVs) of 9 and 18 cm. We evaluated the in-stent stenosis visually, and we measured the attenuation values and the diameter of the patent stent lumen.

Results

The visualization of the stent lumen of the vascular models was improved with using the prospective ECG-gated axial scans and a 9-cm FOV. The inner diameters of the vascular models were underestimated with mean measurement errors of -1.10 to -1.36 mm. The measurement errors were smaller with using the prospective ECG-gated axial scans (Bx-Velocity and Express2, p < 0.0001; Micro Driver, p = 0.0004) and a 9-cm FOV (all stents: p < 0.0001), as compared with the other conditions, respectively. The luminal attenuation value was overestimated in each condition. For the luminal attenuation measurement, the use of prospective ECG-gated axial scans provided less measurement error compared with the retrospective ECG-gated helical scans (all stents: p < 0.0001), and the use of a 9-cm FOV tended to decrease the measurement error.

Conclusion

The visualization of coronary stents is improved by the use of prospective ECG-gated axial scans and using a small FOV with reduced blooming artifacts and increased spatial resolution.

Assessment of Coronary Stent In Vitro on Multislice Computed Tomography Angiography

OBJECTIVE

To assess the effect of tube voltage on the in-stent visibility of coronary stents in vitro on computed tomography (CT) angiography.

METHODS

A total of 6 vascular models (3 models without stenosis and 3 with stenosis) using 3 kinds of stent (Bx Velocity, Express2, and Driver) with an inner diameter of approximately 3.5 mm and filled with contrast material (CT attenuation, 450 Hounsfield units) were scanned by means of a 16-detector row CT. We assessed the visual stenosis evaluation and inhomogeneity of stent lumen in 4 orientations (0-, 30-, 60-, and 90-degree angles) relative to the z-axis of the scanner using 3 imaging techniques (120-kV tube voltage using a medium convolution kernel, 120-kV tube voltage using a convolution kernel for bone, and 140-kV tube voltage using a convolution kernel for bone). Statistical analysis involved F test with a statistical significance of P < 0.05.

RESULTS

The convolution kernel for bone made it easier to evaluate the stenosis inside the stents, although it increased the luminal inhomogeneity significantly (Bx Velocity and Express2, P < 0.005; Driver, P < 0.05). The luminal inhomogeneity tended to increase as the strut diameter and the weight per unit length increased. Using 120-kV tube voltage, the luminal inhomogeneity inside the stents was at the minimum in the angle of 0 degree relative to the z-axis, and at the maximum in the angle of 90 degrees, except for Driver. The 140-kV tube voltage was effective for the improvement of luminal inhomogeneity and visibility of in-stent stenosis compared with the 120-kV tube voltage.

CONCLUSIONS

The in-stent visibility of coronary stents on CT angiography can be improved by the use of 140-kV tube voltage with the convolution kernel for bone.

Accuracy of attenuation measurement of vascular wall in vitro on computed tomography angiography: Effect of wall thickness, density of contrast medium, and measurement point

OBJECTIVES

We sought to assess the effects of measurement point, wall thickness, and intravascular density of contrast material on attenuation measurement of vascular wall.

MATERIALS AND METHODS

We used vascular models (actual attenuation value of the wall: 83 HU) with wall thicknesses of 1.5, 1.0, or 0.5 mm, filled with contrast material of 254, 325, or 400 HU. The 9 vascular models were fixed in an oil-filled container and scanned with a 16-detector computed tomography. The wall attenuation values were measured at 1 point for 0.5-mm thickness models, 3 for 1.0-mm thickness models, and 5 for 1.5-mm thickness models with the same interval of 0.25 mm. Total 20 measurements were done for each point.

RESULTS

For 1.0-mm and 1.5-mm thickness models, wall attenuation progressively increased as the measurement points approached the lumen (P < 0.0001). At all the measurement points for 0.5-mm and 1.0-mm thickness models and the 2 inner measurement points for 1.5-mm thickness models, the densities of contrast material affected the wall attenuations significantly (P < 0.0001). At the midportion for 1.5-mm thickness models, the wall attenuations were not affected by the densities of the contrast material (P = 0.6301), and were 65-68 HU.

CONCLUSIONS

The effects of the intravascular density of contrast material, measurement point, and wall thickness should be considered in the attenuation measurement of the wall.

Transglutaminase differentially regulates growth signalling in rat perivenous and periportal hepatocytes

The influence of transglutaminase 2 (TG2) activity on the proliferative effect of epidermal growth factor (EGF) and on EGF receptor affinity in periportal hepatocytes (PPH) and perivenous hepatocytes (PVH) has been investigated using a primary culture system. PPH and PVH subpopulations have been isolated using the digitonin/collagenase perfusion technique. DNA synthesis was assessed by [3H] thymidine incorporation into hepatocytes. The assay for binding of [125I] EGF to cultured hepatocytes was analysed by Scatchard plot analysis. Pretreatment with the TG2 inhibitor monodansylcadaverine (MDC) greatly increased EGF-induced DNA synthesis in both PPH and PVH. Furthermore, [125I] EGF binding studies in PVH treated with MDC indicated that high-affinity EGF receptor expression was markedly up-regulated, whereas in PPH, there was no significant effect. Treatment with retinoic acid (RA), an inducer of TG2 expression, significantly decreased EGF-induced DNA synthesis in both PPH and PVH. Binding studies in the presence of RA revealed that the high-affinity EGF receptor was down-regulated and completely absent in both PPH and PVH. These results suggest that TG2 was involved in the differential growth capacities of PPH and PVH through down-regulation of high-affinity EGF receptors.

Impact of 16-slice computed tomography in percutaneous coronary intervention of chronic total occlusions

The main reason for failure of percutaneous coronary intervention (PCI) of chronic total occlusion (CTO) is because the calcified plaque prevents the guide wire crossing the occlusion. We aimed to identify the route, and characterize plaque components within CTO, using 16-slice computed tomography (MSCT). Twenty three angiographic CTO in 22 patients (mean age 69 +/- 5 years, 17 males) were included. All patients had undergone MSCT prior to PCI. Images were analyzed for lesion visibility and plaque characteristics of CTO. The presence and location of calcified plaque within the CTO were systematically assessed. Each lesion was classified as a noncalcified, moderately calcified, or exclusively calcified plaque. Procedural failure was defined as the inability to cross a guide wire through the occlusion. All coronary routes of CTO segment were visualized. MSCT revealed three markedly bent CTO segments (13.0%), which could not be identified by coronary angiography only. Calcified plaques were detected in 30 lesions of 19 CTO segments (82.6%), but were not detected in the other four. The majority of calcified plaque was located in the proximal lesion, or both proximal and distal lesions. Fifteen out of 30 calcified lesions (50.0%) were exclusively calcified plaques. Overall procedural success was obtained in 21 CTOs (91.3%). MSCT can accurately identify the route of the CTO segment and evaluate both distribution and amount of the calcified plaque within it. Even with the complicated and/or calcified lesions, PCI success rate was excellent under MSCT guidance. MSCT should become a useful tool in PCI of CTO.

Accuracy and Efficiency of Left Ventricular Ejection Fraction Analysis, Using Multidetector Row Computed Tomography Effect of Image Reconstruction Window Within Cardiac Phase, Slice Thickness, and Interval of Short-Axis Sections

BACKGROUND

The aim of the present study was to assess the accuracy and efficiency of left ventricular ejection fraction (LVEF) analysis by multidetector row computed tomography (CT).

METHODS AND RESULTS

The CT data of 21 patients were analyzed by semi-automated software on a workstation. In analysis of LVEF using systolic volumes in the 6 phases (30-55%), systolic images of 10% interval (35, 45, 55%) were underestimated with a mean measurement error of -0.4% and the standard error of the estimate (SEE) of 0.6%, compared with the LVEF using images of 5% interval. In analysis of LVEF using 3-slice thicknesses of axial images (1, 2, and 3 mm), and 3-slice numbers of short-axis sections (10 14, and 30 slices), there was no significant difference between the SEE of the intraobserver reproducibility and that of the analysis with 30 short-axis sections using axial images of 1-, 2- and 3-mm thickness, and that with 14 short-axis sections using axial images of 1- and 2-mm thickness. The mean analysis times were 96.9 s, 119.8 s, and 227.0 s for the analysis with 10, 14, and 30 short-axis sections, respectively.

CONCLUSION

The proper selection of the reconstruction interval in the cardiac phase, the slice thickness of the axial images, and the number of short-axis sections reduces the analysis time, maintaining the accuracy of LVEF analysis. This will be acceptable for practical use at present, although more accurate analysis is preferable.

Laser-Induced Liquid-to-Droplet Extraction of Chlorophenol: Photothermal Phase Separation of Aqueous Triethylamine Solutions

Thermal phase separation of aqueous triethylamine (TEA) solutions (TEA wt % = 6.5-6.7 in H2O) was induced by irradiating a focused 1064-nm laser beam (spot size approximately 1 mum) under an optical microscope, and this produced a single micrometer-sized TEA droplet as demonstrated by in situ Raman microspectroscopy. Since H2O absorbs 1064-nm light, heat is generated at the focal spot of the incident laser beam, giving rise to photothermal phase separation of the aqueous TEA solution. The TEA droplet produced by phase separation was trapped simultaneously by the incident laser beam. In the presence of p-chlorophenol (CP) in an aqueous TEA solution, laser-induced photothermal phase separation and simultaneous TEA droplet formation brought about extraction/concentration of CP from the surrounding solution phase to the TEA droplet (approximately 15-mum diameter and 1.7-pL volume). Raman microspectroscopy demonstrated that the distribution coefficient of CP (KD) between the solution phase and the single TEA droplet was KD(drop) = approximately 21, while that in a bulk TEA/H2O system was KD(bulk) = 4.7. The larger KD(drop) value as compared to KD(bulk) was discussed in terms of radiation pressure exerted on CP in the TEA droplet.

Conformation and lytic activity of eumenine mastoparan: a new antimicrobial peptide from wasp venom

Eumenine mastoparan-AF (EMP-AF) is a novel membrane active tetradecapeptide recently isolated from the venom of solitary wasp, Anterhynchium flavomarginatum micado. It was reported previously that EMP-AF peptide presented low cytolytic activities in human erythrocytes and in RBL-2H3 mast cells. In the present work, we observed that this peptide is able to permeate anionic liposomes, and in less extension also the neutral ones. We present evidences showing that the permeation ability is well correlated with the amount of helical conformation assumed by the peptides in these environments. This peptide also showed a broad-spectrum inhibitory activity against Gram-positive and Gram-negative bacteria. The permeability of liposomes and the antibiotic effect showed a significant reduction when C-terminus was deamidated (in acidic form). The removal of the three first amino acid residues from the N-terminus rendered the peptide inactive both in liposomes and in bacteria. The results suggest that the mechanism of action involves a threshold in the accumulation of the peptide at level of cell membrane.

A severe hepatic disorder with myelodysplastic syndrome, treated with cytarabine ocfosfate, in a dog

An 8-year-old female Shih Tzu was presented with weight loss and vomiting. Alanine aminotransferase was high and abdominal radiographs revealed hepato- and splenomegaly. Mild anaemia, neutrophilia with left shift, eosinophilia, a thrombocytosis with dysplastic features of eosinophils and platelets, were detected. The animal was initially considered to have hepatitis and was treated accordingly, but clinical signs persisted. Histological examination of liver biopsy samples showed disruption of the hepatic lobule, with extensive infiltration by haemopoietic cells. Further investigation of the bone marrow suggested a diagnosis of myelodysplastic syndrome. The animal was treated with cytarabine ocfosfate, a prodrug of cytosine arabinoside, and appeared to recover.

Differentiation of exudate from transudate ascites by Doppler sonography

BACKGROUND

We investigated whether the addition of Doppler sonography (US) increases the diagnostic confidence of US for estimating the nature of ascites.

METHODS

Of the 127 cases reviewed in this study, there were 42 cases of transudate and 85 of exudate ascites. We reviewed the US, power Doppler, and pulsed Doppler images of these cases.

RESULTS

With US, the transudate ascites was imaged as free of echo in 38 of 42 cases (90.5%). The exudate ascites was imaged as free of echo in 22 of 85 cases (25.9%) and with internal echo spots in 63 of 85 cases (74.1%). With Doppler US, we obtained distinct pulsed signals from the transudate ascites in only two of 36 cases (5.6%). In contrast, we obtained distinct Doppler signals from the exudate ascites in 66 of 79 cases (83.5%). Those 66 cases included 16 of the 22 cases with echo-free ascites.

CONCLUSION

The presence or absence of echo spots within the ascites helped differentiate transudate from exudate ascites, as reported in the literature. However, the addition of Doppler US contributed to the differentiation of echo-free exudate (Doppler signals present) from echo-free transudate (Doppler signals absent) ascites.

Appendiceal mucocele: sonographic findings

BACKGROUND

Appendiceal mucocele (AM) is a relatively rare disease, and its sonograms (US) have not been sufficiently analyzed.

METHODS

We studied the US findings of five patients with AM, with special attention to AM size, shape, internal echoes, and the mode of back echoes.

RESULTS

All five cases showed an elongated mass in the lower right abdomen. Internal echoes were present in all cases and M-mode US confirmed the movement of those echoes. The echogenecity of the lesion changed according to the frequency of the transducer used. Only one case showed posterior echo enhancement, and no case showed lateral shadowing.

CONCLUSION

AM appears as an elongated echo-poor mass without posterior echo enhancement. The cyst wall is less distinct than what one would expect for a cyst. When encountering such a mass in the lower right abdomen, one should strongly suspect an AM. In such cases, appropriate diagnostic and therapeutic strategies are especially necessary to prevent rupture that results in development of pseudomyxoma peritonei.

Dilatation of the cystic duct in patients with obstructive jaundice

BACKGROUND

It is well known that obstructive jaundice causes biliary dilatation, but sonographic (US) findings of the cystic duct in patients with obstructive jaundice are rarely reported.

METHODS

We reviewed US findings in 25 such patients.

RESULTS

US findings of dilated cystic duct could be divided roughly into two patterns: tortuous and tubular. The former pattern was a tortuously dilated cystic duct arising from the gallbladder neck, running predominantly deeply, turning anteromedially, and then joining the posterior face of the common hepatic duct. The latter pattern was a straight dilated cystic duct running parallel with the common hepatic duct, giving the appearance of a septated bile duct.

CONCLUSION

A better understanding of the US findings of dilated cystic duct translates into improved biliary US diagnosis.

Retroperitoneal cyst: sonographic findings

BACKGROUND

Retroperitoneal cyst (RC) is a relatively rare disease, and its sonographic (US) findings have not been analyzed sufficiently.

METHODS

We studied US findings of five patients with RC, with special attention to location, size, shape, internal echoes, the presence or absence of lateral shadowing, and the mode of back echoes.

RESULTS

In all cases, the cyst was situated behind (four cases) or lateral to (one case) the pancreas: behind or lateral to the pancreatic head in two cases, behind the pancreatic body in one case, and behind the pancreatic tail in two cases. Four cases showed a round mass (three cases) or multiple round mass (one case). Internal echoes were present in those cases and showed a "pseudo-solid" pattern. In those cases, M-mode US confirmed the movement of those internal echoes. In the remaining case, the lesion was imaged as an irregularly shaped multilocular mass. No case showed posterior echo enhancement, and no case showed lateral shadowing. No blood flow signals from the lesion were seen.

CONCLUSION

Unlike ordinary cysts, RC usually is imaged as a round mass behind the pancreas, with dense internal echoes without lateral shadowing or posterior echo enhancement, which presents a "pseudo-solid" pattern. A diagnosis of RC should be considered when encountering a mass with such US findings.

Potential remedy against Echinococcus multilocularis in wild red foxes using baits with anthelmintic distributed around fox breeding dens in Hokkaido, Japan

The effect of bait-delivered anthelmintic to reduce the prevalence of Echinococcus multilocularis in wild red foxes was evaluated in Koshimizu, in the eastern part of Hokkaido, Japan. The study area (200 km2) was divided into baited and non-baited sections. The anthelmintic baits were distributed around fox den sites in the baited section every month for 13 months. After 1 year of the anthelmintic bait distribution, the prevalence of E. multilocularis in foxes, evaluated either by the parasite egg examination (from 27.1 to 5.6%) or coproantigen ELISA (from 59.6 to 29.7%), decreased in the baited section contrasting to that in the non-baited section (parasite egg: from 18.8 to 24.2%; ELISA: from 41.9 to 45.8%). The prevalence of E. multilocularis in grey red-backed vole Clethrionomys rufocanus, caught around fox dens, born after bait distribution also decreased and was significantly lower than that in non-baited section. However, within the study periods, the coproantigen-positive rate in fox faeces sporadically increased, while egg-positive rate constantly decreased. Since coproantigen ELISA can detect pre-patent infection, this observation indicates that reinfection pressure in the baited section was still high even after the 13 months of anthelmintic bait distribution. Therefore, the bait distribution longer than our study period is required for the efficient control of E. multilocularis in wild red fox population.

Abdominal lymphoma: differentiation from pancreatic carcinoma with Doppler US

BACKGROUND

Marked lymphadenopathy around the pancreas due to lymphoma (abdominal lymphoma) occasionally can mimic a total pancreatic carcinoma on ultrasonography (US). We investigated whether US and color Doppler US allowed differentiation between those pathologies.

METHODS

We analyzed the US and color Doppler results of 12 cases of abdominal peripancreatic lymphoma and 21 cases of total pancreatic carcinoma.

RESULTS

With regard to shape, echogenicity of the lesion, and mode of vascular involvement, there was no difference between groups. With regard to maximal velocities and resistive indices of the involved vessels, there was no difference between groups. However, the presence of turbulent flows in the involved vessels was seen exclusively in the pancreatic carcinoma group.

CONCLUSION

The presence or absence of turbulent flow in the involved vessels is a very important finding for differentiating abdominal lymphomas from total pancreatic carcinomas.

Accessory hepatic duct: sonographic findings

Accessory hepatic ducts are relatively rare biliary anomalies. They have been reported only sporadically, and very few reports have described their sonographic (US) findings. Our experience with two such cases suggested that a diagnosis of an accessory hepatic duct should be considered when US shows a fine tubular structure or an anechoic or hypoechoic oval mass with acoustic shadowing at the level between the hepatic hilus and the common bile duct. A good knowledge of the US findings will determine the diagnostic and therapeutic strategies.

Primary carcinoid tumor of the liver: report of two cases with an emphasis on US findings

Primary carcinoid tumor of the liver is rare, and its sonographic (US) findings have rarely been reported. We present two histologically proven cases. Both patients were asymptomatic and huge masses, found incidentally by US, were echogenic with many cystic areas. Lesions were markedly hypervascular on color Doppler US and angiography. Thus, primary carcinoid tumor of the liver should be considered when US detects this type of mass in asymptomatic patients.

Mesenteric lipoma: report of a case with emphasis on US findings

Mesenteric lipoma (ML) is a relatively rare disease that has been very infrequently reported. We present the clinical data and medical imaging results of an asymptomatic case with ML incidentally detected by sonography (US). On US the lesion was imaged as a well-demarcated hypoechoic mass with multiple linear echoes. The mass also changed location under probe compression. The lesion was imaged as a clearly demarcated non-enhanced homogeneous fat-density mass on CT. Color Doppler US and angiography confirmed the avascular nature of the mass. Knowledge of the US findings in this case is useful for the diagnosis of ML.

Emphysematous cholecystitis: sonographic findings

BACKGROUND

Emphysematous cholecystitis (EC) is a rare but life-threatening complication of acute cholecystitis, and an early diagnosis is required to prevent delay in patient management. Because sonography (US) is the first choice for diagnosing gallbladder diseases, US findings of EC should be understood more precisely.

METHODS

We reviewed US findings of 11 surgically proven cases of EC (with small amounts of gas in three cases and large amounts in eight cases) and compared those with patients' clinical data.

RESULTS

(1) In cases with small amounts of gas, US showed an echogenic line with a distinct ring-down artifact or a "powder snow-like" speckled posterior echo. (2) In cases with large amounts of gas, US showed a wide spiculated echogenic band with a powder snow-like speckled posterior echo or a speckled acoustic shadowing. In all cases, the presence of gas prevented visualization of the gallbladder wall. (3) US did not differentiate gas localized to the gallbladder wall and gas extending to the surrounding hepatic tissue. (4) Two diabetic cases showed gas throughout the intrahepatic bile ducts. In those cases, the time from diagnosis to recovery was relatively long.

CONCLUSION

Our series showed some characteristic US patterns of EC. A good understanding of its US findings and appropriate emergent management will reduce the serious morbidity and mortality rates caused by EC.

Mechanism of selective inhibition of respiratory syncytial virus by a benzodithiin compound (RD3-0028)

RD3-0028, a compound with a benzodithiin structure, was found to be a potent inhibitor of respiratory syncytial virus (RSV) replication. Its action is specific; no activity is seen against influenza A virus, measles virus, herpes simplex virus type 1 or 2, or human cytomegalovirus. A time-dependent drug addition experiment indicated that the antiviral activity occurs in the late stage of the RSV replication cycle, since this compound completely inhibited syncytium formation even when added up to 16 hr after the infection of cell monolayers at an MOI of 3. RD3-0028 had no direct virucidal effect on RSV. Western blotting analysis showed that RD3-0028 significantly decreased the amount of RSV proteins released into the cell culture medium. Moreover, five independent isolates of the RSV long strain were selected for growth in RD3-0028 (5-20 microg/ml). These resistant viruses were more than 80-fold less sensitive to RD3-0028 than the long strain. The F gene segment of each of these viruses was sequenced and in each case the mutant RNA segment contained at least one sequence alteration, converting asparagine 276 to tyrosine (F1 protein). These results suggest that RD3-0028 inhibits RSV replication by interfering with intracellular processing of the RSV fusion protein, or a step immediately thereafter, leading to loss of infectivity.

Segmental chronic cholecystitis: sonographic findings and clinical manifestations

BACKGROUND

In chronic cholecystitis, the gallbladder (GB) wall is usually evenly involved, whereas marked segmental thickening of the GB wall (segmental cholecystitis) seldom is reported. We wanted to define its clinical manifestations and sonographic (US) findings.

METHODS

We reviewed the clinical and US data of 13 cases and compared these results with those of 30 patients with chronic cholecystitis with evenly thickened GB walls (usual-cholecystitis group).

RESULTS

(a) All cases of segmental cholecystitis showed the portion distal to the kinking to be markedly thickened. (b) The thickened portion corresponded to the fundus in three cases, the body and fundus in seven cases, and the fundus, body, and infundibulum in three cases; and the thickened distal portion contained many stones in 11 cases. (c) There was no difference in the maximal diameters of the GB walls between the segmental-cholecystitis group and the usual-cholecystitis group. However, there was a significant difference in the minimal diameters of the GB walls between groups.

CONCLUSION

Knowledge of the US findings and clinical presentations of segmental cholecystitis can help in the development of appropriate diagnostic and therapeutic strategies.

Pharmacokinetics of a benzodithiin (RD3-0028) following aerosol treatment in rat

1. RD3-0028, a benzodithiin compound, has potent antiviral activity against respiratory syncytial virus (RSV) in cell culture. The compound also inhibits growth of RSV and improves pathologic changes of interstitial pneumonia in the immunosuppressed mouse when delivered by small-particle aerosol. 2. In the present study, the absorption, distribution and excretion of 14C-RD3-0028 were compared in rat following either a single aerosol treatment or oral administration. 3. The plasma concentration was maintained at the same level from 5 min to 1 h, and decreased with a half-life of 2.2 +/- 0.1 h for 1-8 h. 4. The excretion of radioactivity in the urine and faeces at 24 h after aerosol treatment was 89.3 and 4.5%, respectively, indicating that almost all the radioactivity was rapidly excreted in the urine. The excretion of total radioactivity was 98.9% within 168 h. 5. The concentrations of radioactivity in the lung and trachea following aerosol treatment were higher than those in other tissues, and were detected even at 72 h. 6. These results suggest that the aerosol treatment might be useful for delivering RD3-0028 to the respiratory tract of RSV-infected patients.

Gallbladder perforation: color Doppler findings

Gallbladder (GB) perforation is a life-threatening complication of acute cholecystitis, and early diagnosis prevents delay in patient management. We present two cases of GB perforation diagnosed by color Doppler ultrasonography. Each clearly showed a flow signal passing through the perforated site, leading to prompt and successful surgical treatment. This interesting observation suggests that color Doppler ultrasonography is useful in the diagnosis of GB perforation.

Efficient and versatile synthesis of novel 2alpha-substituted 1alpha,25-dihydroxyvitamin D(3) analogues and their docking to vitamin D receptors

Novel 2alpha-substituted 1alpha,25-dihydroxyvitamin D(3) analogues with 2alpha-alkyl and 2alpha-hydroxyalkyl groups were systematically synthesized from D-xylose. Their conformation on binding to the ligand binding domain (LBD) of the vitamin D receptor was analyzed. It has been found that the 2alpha-hydroxypropyl group best fits the cavity of the LBD, and the binding activity is three times higher than that for the natural hormone.