Tailored Adjunctive Cilostazol Therapy Based on CYP2C19 Genotyping in Patients With Acute Myocardial Infarction　- The CALDERA-GENE Study.

BACKGROUND: Patients with reduced-function CYP2C19 genotypes on dual antiplatelet therapy (DAPT) with aspirin and clopidogrel show higher clinical risk for acute myocardial infarction (AMI). We investigated the effect of CYP2C19 genotype-tailored adjunctive cilostazol therapy on treatment of AMI.Methods and Results:The study group of 138 patients with suspected AMI were screened for CYP2C19 genotype immediately after percutaneous coronary intervention (PCI) using a SPARTAN RX point-of-care device. Carriers of the CYP2C19 reduced-function allele were randomized into DAPT (Carrier/DAPT) and DAPT plus 14-day cilostazol (Carrier/DAPT+Cilostazol) groups, while noncarriers were treated with DAPT (Noncarrier/DAPT). After exclusion of 10 patients, the remaining 128 patients were analyzed for P2Y12 reaction unit (PRU) using VerifyNow®P2Y12 system, and levels of biomarkers immediately after, and 1, 14, and 28 days after PCI. DAPT+Cilostazol reduced PRU levels in carriers (n=46) to those found in the Noncarrier/DAPT group (n=40), and significantly lower than those of the Carrier/DAPT group (n=42) at 14 days post-PCI. Discontinuation of cilostazol for 14 days was associated with a significant rise in PRU levels to those of the Carrier/DAPT group at 28 days post-PCI. Plasma B-type natriuretic peptide levels at 14 days post-PCI were lower in Carrier/DAPT+Cilostazol than in the other 2 groups, and the levels increased to those of the other groups at 28 days post-PCI after withdrawal of cilostazol. CONCLUSIONS: Adjunctive cilostazol therapy tailored to CYP2C19 genotype seemed useful in AMI patients with the CYP2C19 reduced-function allele.

Antithrombotic effects of losartan in patients with hypertension complicated by atrial fibrillation: 4A (Angiotensin II Antagonist of platelet Aggregation in patients with Atrial fibrillation), a pilot study.

Angiotensin receptor blockers (ARBs) are widely used for the treatment of hypertension. It has been reported that the ARB losartan has antiplatelet, anticoagulant and profibrinolytic effects experimentally. These properties could be desirable to treat hypertensive patients with high atherothrombotic and/or thromboembolic risk. To examine the antithrombotic effects of losartan in hypertension, 20 consecutive patients with hypertension complicated by atrial fibrillation (AF) were enrolled in this study. The patients were treated with losartan 50 mg for 8 weeks followed by 100 mg for 4 weeks. Blood samples were obtained from each patient at 0 (pretreatment), 8 and 12 weeks after initiating treatment. Platelet aggregability, plasma levels of tissue factor (TF) and type 1 plasminogen activator inhibitor (PAI-1) activity levels were measured. The area under the curve for small platelet aggregability decreased from 100 to 42.8% at 12 weeks (P<0.0001). TF levels (ng ml(-1)) and PAI-1 activity (IU ml(-1); mean±s.d.) also changed from 14.2±3.6 to 10.9±4.5 at 12 weeks (P=0.0299) and from 11.7±3.6 to 8.5±3.1 at 12 weeks (P=0.0122), respectively. Losartan inhibited platelet activity and coagulation factors in a dose- and time-dependent manner in patients with hypertension complicated by AF, whereas the fibrinolytic capacity was increased. The use of losartan could be advantageous in the treatment of hypertensive patients with high atherothrombotic risk.

Design, Synthesis, and Chemical and Biological Properties of Cyclic ADP-4-Thioribose as a Stable Equivalent of Cyclic ADP-Ribose.

Here we describe the successful synthesis of cyclic ADP-4-thioribose (cADPtR, 3), designed as a stable mimic of cyclic ADP-ribose (cADPR, 1), a Ca2+-mobilizing second messenger, in which the key N1-ß-thioribosyladenosine structure was stereoselectively constructed by condensation between the imidazole nucleoside derivative 8 and the 4-thioribosylamine 7 via equilibrium in 7 between the α-anomer (7α) and the ß-anomer (7ß) during the reaction course. cADPtR is, unlike cADPR, chemically and biologically stable, while it effectively mobilizes intracellular Ca2+ like cADPR in various biological systems, such as sea urchin homogenate, NG108-15 neuronal cells, and Jurkat T-lymphocytes. Thus, cADPtR is a stable equivalent of cADPR, which can be useful as a biological tool for investigating cADPR-mediated Ca2+-mobilizing pathways.

Differentiation of histological subtypes in lung cancer with 18F-FDG-PET 3-point imaging and kinetic analysis.

The purpose of this study was to evaluate differences in histological subtypes of lung cancer using (18)F-FDG-PET 3-point imaging and kinetic analysis. Subjects comprised 44 patients with histologically proven lung cancer (squamous cell carcinoma (SCC), n=18; well-differentiated adenocarcinoma (WDA), n=9; poorly/moderately differentiated adenocarcinoma (non-WDA), n=17) who underwent (18)F-FDG-PET/CT examinations at 1, 2 h and 3 h after injection of 185 MBq of (18)F-FDG, approximately. Mean standardized uptake value (SUV) in each lesion was measured at each time point and the increase rate of SUV (IR_SUV) was calculated. SUV and IR_SUV were compared among the 3 groups. In addition, to estimate differences in kinetic parameters for each group, kinetic analysis based on a 3-compartment model was performed. Our results showed SUV differed significantly at every time point among the 3 groups. IR_SUV between 2 and 3 h post-injection (IR_SUV (2-3)) differed significantly among the 3 groups, while both IR_SUV(1-3) and IR_SUV(1-2) were significantly higher in SCC than in WDA. In kinetic analyses, both K1 and k3 showed significant differences among the 3 groups, with highest values in SCC and lowest in WDA. In conclusion, (18)F-FDG-PET 3-point imaging and kinetic analysis enabled the differentiation of histological subtypes in lung cancer, arising from differences in glucose transporter density and enzymatic activity of hexokinase.

Epidermal nevus syndrome associated with anterior scleral staphyloma and ectopic bone and cartilaginous intraocular tissue.

BACKGROUND: Epidermal nevus syndrome encompasses a group of congenital neurocutaneous anomalies characterized by epidermal nevi in association with cerebral, ocular, and skeletal abnormalities. We report herein the case of a Japanese girl with epidermal nevus syndrome associated with complex ocular choristoma and discuss the histopathological findings. CASE: A mass lesion was noted on the left eyeball of a newborn Japanese girl. The lesion appeared to be a scleral staphyloma. Linear and diffuse acanthoses were also apparent on the face. Skin biopsy revealed an epidermal nevus. Histopathological examination of the enucleated left eyeball demonstrated that extremely thin sclera adjacent to the corneal limbus resulted in anterior staphyloma, and ectopic osteocartilaginous tissues were present in the posterior sclera. CONCLUSION: Epidermal nevus syndrome associated with complex ocular choristoma was diagnosed. The anterior staphylomatous lesion observed in this case has not been reported previously.

Mevalonate analogues as substrates of enzymes in the isoprenoid biosynthetic pathway of Streptococcus pneumoniae.

Survival of the human pathogen Streptococcus pneumoniae requires a functional mevalonate pathway, which produces isopentenyl diphosphate, the essential building block of isoprenoids. Flux through this pathway appears to be regulated at the mevalonate kinase (MK) step, which is strongly feedback-inhibited by diphosphomevalonate (DPM), the penultimate compound in the pathway. The human mevalonate pathway is not regulated by DPM, making the bacterial pathway an attractive antibiotic target. Since DPM has poor drug characteristics, being highly charged, we propose to use unphosphorylated, cell-permeable prodrugs based on mevalonate that will be phosphorylated in turn by MK and phosphomevalonate kinase (PMK) to generate the active compound in situ. To test the limits of this approach, we synthesized a series of C(3)-substituted mevalonate analogues to probe the steric and electronic requirements of the MK and PMK active sites. MK and PMK accepted substrates with up to two additional carbons, showing a preference for small substituents. This result establishes the feasibility of using a prodrug strategy for DPM-based antibiotics in S. pneumoniae and identified several analogues to be tested as inhibitors of MK. Among the substrates accepted by both enzymes were cyclopropyl, vinyl, and ethynyl mevalonate analogues that, when diphosphorylated, might be mechanism-based inactivators of the next enzyme in the pathway, diphosphomevalonate decarboxylase.

Synthesis of 5''-branched derivatives of cyclic ADP-carbocyclic-ribose, a potent Ca2+-mobilizing agent: The first antagonists modified at the N1-ribose moiety.

The 5''-branched cyclic ADP-carbocyclic-ribose derivatives were designed and synthesized. These target compounds were identified as the first antagonists of cADPR without a substituent at the adenine 8-position, and were shown to be stable due to the N1-carbocyclic-ribosyl structure.

Reproducibility of semi-quantitative parameters in FDG-PET using two different PET scanners: influence of attenuation correction method and examination interval.

PURPOSE: The aim of this study is to evaluate the reproducibility of semi-quantitative parameters obtained from two 2-deoxy-2-[F-18]fluoro-D-glucose-positron emission tomography (FDG-PET) studies using two different PET scanners. METHODS: Forty-five patients underwent FDG-PET examination with two different PET scanners on separate days. Two PET images with different attenuation correction method were generated in each patient, and three regions of interest (ROIs) were placed on the lung tumor and normal organs (mediastinum and liver) in each image. Mean and maximum standardized uptake values (SUVs), tumor-to-mediastinum and tumor-to-liver ratios (T/M and T/L), and the percentage difference in parameters between two PET images (% Diff.) were compared. RESULTS: All measured values except maximum SUV in the liver and tumor-related parameters (SUV in lung tumor, T/M, T/L) showed no significant difference between two PET images. CONCLUSION: The mean measured values showed high reproducibility and demonstrate that follow-up study or measurement of tumor response to anticancer drugs can be undertaken by FDG-PET examination without specifying the particular type of PET scanner.

Class A macrophage scavenger receptor gene expression levels in peripheral blood mononuclear cells specifically increase in patients with acute coronary syndrome.

OBJECTIVE: Morbidity and mortality rates are still high among patients with acute coronary syndrome (ACS); moreover, it is clinically difficult to determine precisely which patients will progress satisfactorily. Unstable plaque is characterized by an increased number of activated inflammatory cells, including macrophages and lymphocytes, and an increased release of numerous inflammatory mediators and proteolytic enzymes. Mononuclear cells consist of monocytes/macrophages and lymphocytes and are able to be experimentally isolated. We searched for a specific risk factor for ACS in the peripheral blood mononuclear cells (PBMCs). METHODS AND RESULTS: We examined the expression of 12,625 genes in PBMCs utilizing a gene chip microarray system in ACS patients in acute and chronic stable phases. The gene expression profiles revealed that class A macrophage scavenger receptors (SR-A), among the immune response factors and the receptor activity markers, were the most strongly increased in the acute phase. We examined SR-A gene expression levels of PBMCs using real time RT-PCR in 122 consecutive patients: 32 ACS patients; 41 stable angina patients; and, 49 control subjects. The SR-A gene expression levels of the PBMCs were highest in the ACS patients (p<0.0001). The occurrence of a reattack of a cardiovascular event was significantly lower in the low SR-A group than in the high SR-A group (p<0.001). CONCLUSION: SR-A gene expression level in the PBMCs specifically increases in patients with ACS, and provides a predictive marker for a reattack of a cardiovascular event.

Selective neuronal damage and chronic hemodynamic cerebral ischemia.

OBJECTIVE: In atherothrombotic internal carotid artery or middle cerebral artery (MCA) occlusive disease, chronic hemodynamic compromise may increase the risk for cerebral ischemic damage. To determine whether selective neuronal damage demonstrated as a decrease in central benzodiazepine receptor (BZR) in the normal-appearing cerebral cortex is associated with increased oxygen extraction fraction (OEF) (misery perfusion). METHODS: We measured BZR and OEF using positron emission tomography in 105 nondisabled patients with atherothrombotic internal carotid artery or MCA occlusive disease and no cortical infarction. By using three-dimensional stereotactic surface projections and the stereotactic extraction estimation method, without correction for partial volume effects, the abnormally decreased BZR index [(the extent of the pixels with Z-score more than 2 compared with controls) x (average Z-score in those pixels)] in the cerebral cortex of the MCA distribution with arterial disease was calculated, and it was found to be correlated with the mean hemispheric value of OEF and several clinical variables. RESULTS: All patients had pixels with abnormally decreased BZR, with the extent varying from 0.04 to 60.91%. Multivariate analysis showed that the abnormally decreased BZR index was positively correlated with the value of OEF and the history of stroke, whereas it was negatively correlated with the presence of hypercholesterolemia with statin treatment. Follow-up examinations of 17 patients without ischemic episode showed that a decrease of BZR was associated with an increase of OEF. INTERPRETATION: In atherothrombotic internal carotid artery or MCA occlusive disease, misery perfusion may cause selective neuronal damage, and statins might have beneficial effects against neuronal damage.

Substitution at the 8-position of 3''-deoxy-cyclic ADP-carbocyclic-ribose, a highly potent Ca2+-mobilizing agent, provides partial agonists.

We previously showed that 3''-deoxy-cyclic ADP-carbocyclic-ribose (3''-deoxy-cADPcR, 4) is a stable and highly potent analogue of cyclic ADP-ribose (cADPR, 1), a Ca(2+)-mobilizing second messenger. From these results, we designed and synthesized other 3''-modified analogues of cADPcR having a substituent at the 8-position and found that this modification at the 8-position made them partial agonists. Among these compounds, 8-NH(2)-3''-deoxy-cADPcR (10) was identified as a potent partial agonist with an EC(50) value of 17 nM.

Synthesis of 5''-substituted cyclic ADP-carbocyclic-ribose as biological tools.

5''-Branched cyclic ADP-carbocyclic-riboses (4 and 5) were designed as biological tools for identifying the target proteins of cyclic ADP-ribose, an intracellular Ca(2+)-mobilizing second messenger. One of the targets, 4, successfully synthesized.

Synthesis of cyclic ADP-carbocylcic-xylose and its 3"-O-methyl analogue as stable and potent Ca2+ -mobilizing agents.

We previously showed that 3"-deoxy-cyclic ADP-carbocyclic-ribose (3"-deoxy-cADPcR, 3) is a stable and highly potent analogue of cyclic ADP-ribose (cADPR, 1), a Ca2+ -mobilizing second messenger. From these results, we newly designed another 3"-modified analogues of cADPcR and identified the N1-"xylo"-type carbocyclic analogue, i.e., cADPcX (4), as one of the most potent cADPR-related compounds reported so far.

Relation between platelet microaggregates and ankle brachial index in patients with peripheral arterial disease.

INTRODUCTION: Peripheral arterial disease is one of the systemic atherosclerotic diseases, and patients with the disorder are classified in the high risk group of coronary artery disease. A lower ankle brachial index is a frequent finding in peripheral arterial disease. While platelet microaggregates are a significant predictor of adverse clinical outcome in coronary artery disease, the significance of platelet aggregability in peripheral arterial disease has not been elucidated. MATERIALS AND METHODS: Small platelet aggregates measured using laser-light scattering and ankle brachial index were determined in 42 patients with both coronary artery disease and peripheral arterial disease (peripheral group), 56 patients with only coronary artery disease (coronary group) and 32 patients without both (control group). RESULTS: The level of small platelet aggregates was increased significantly in the peripheral group (4.3 x 10(4) [range 2.2 x 10(4) to 7.4 x 10(4)]) compared with both the coronary (1.1 x 10(4) [range 0.3 x 10(4) to 5.0 x 10(4)]) and control groups (0.5 x 10(4) [range 0.1 x 10(4) to 0.9 x 10(4)]). There was a significant inverse correlation between log small platelet aggregates and ankle brachial index (n=130, r=-0.422, p<0.001). Multivariate logistic regression analysis revealed that a lower ankle brachial index (<0.90) was an independent determinant of increased levels of small platelet aggregates. CONCLUSIONS: Platelet aggregability was increased in patients with peripheral arterial disease with the degree of platelet aggregation being closely associated with ankle brachial index. It is possible that this change in platelet activity may be one mechanism to explain why a lower ankle brachial index is a predictor of poor prognosis in patients with peripheral arterial disease.

Increased plasma levels of thioredoxin in patients with glucose intolerance.

OBJECTIVE: The aim of the present study was to determine the effects of glucose intolerance on oxidative stress in patients with coronary artery disease (CAD). METHODS: The patients were divided into 3 groups, diabetes mellitus (DM), IGT or normal glucose tolerance (NGT) according to the criteria of the American Diabetes Association. PATIENTS: The present study consisted of 178 consecutive patients who underwent diagnostic coronary arteriography and a 75-g glucose tolerance test. RESULTS: The level of plasma thioredoxin, a marker of oxidative stress was measured in every patient during the fasting state. The levels of plasma thioredoxin were significantly higher in the DM and IGT groups than the NGT group. Furthermore, we found that there was a positive association between thioredoxin levels and glycosylated hemoglobin (sigma=0.225, p=0.018). In multivariate logistic regression analysis, glucose intolerance (DM or IGT) was only independently associated with the high levels of thioredoxin. The levels of plasma thioredoxin were significantly higher in the CAD group compared to the non-CAD group. In multivariate logistic regression analysis, high levels of thioredoxin, male, age and hypertension were independently associated with the presence of CAD. CONCLUSION: Glucose intolerance was associated with the high levels of thioredoxin. High levels of thioredoxin were related to the presence of CAD. The measurement of thioredoxin as the marker of oxidative stress may be useful for monitoring the development of the cardiovascular diseases.

Selective neuronal damage and borderzone infarction in carotid artery occlusive disease: a 11C-flumazenil PET study.

UNLABELLED: The pathogenesis of selective neuronal damage in internal carotid artery (ICA) occlusive disease is unclear. Imaging of the central-type benzodiazepine receptor (BZR), which is expressed by most cortical neurons, provides information on the neuronal alterations induced by ischemia in vivo. Hemodynamic ischemia due to ICA occlusive disease may cause not only borderzone infarction but also selective neuronal damage beyond the regions of infarcts, which may be detected by a decrease in BZR in the normal-appearing cerebral cortex. The purpose of this study was to determine whether selective neuronal damage is associated with borderzone infarction in ICA occlusive disease. METHODS: We measured BZR using PET and 11C-flumazenil in 62 nondisabled patients with ICA steno-occlusive lesions in the chronic stage. Flumazenil binding potential (BP) was calculated using the dynamic data and the reference tissue model. The infarcts on MRI-which were categorized as territorial, borderzone (external or internal), striatocapsular, lacunar, and other white matter infarcts-were correlated with the mean cerebral/cerebellar cortical BP ratio in the hemisphere with ICA occlusive disease. RESULTS: Patients with borderzone infarction (n=18) had a significantly decreased flumazenil BP ratio in the hemisphere with ICA occlusive disease compared with patients without borderzone infarction (n=44) and healthy control subjects (n=10). Multivariate analysis showed that external borderzone infarction was an independent predictor of the decreased flumazenil BP ratio. CONCLUSION: In ICA occlusive disease, selective neuronal damage demonstrated as decreased BZR is associated with borderzone infarction, suggesting that hemodynamic ischemia leading to borderzone infarction may cause selective neuronal damage beyond the regions of infarcts in the chronic stage.

Synthesis and biological activity of cyclic ADP-carbocyclic-ribose analogs: structure-activity relationship and conformational analysis of N-1-carbocyclic-ribose moiety.

Several cyclic ADP-carbocyclic-ribose analogs 3-10 modified in the N-1-carbocyclic-ribose moiety were synthesized. Their Ca2+-releasing activity was estimated in sea urchin eggs to show that the 3"-deoxy analog 6 shows 5 times more potent activity than cADPcR, but the 2",3"-didieoxy-2",3"-unsunsaturated analog 3 has very weak activity. We also calculated their stable conformation and found that 3 and 6 were significantly different in their stable conformation.

Amplification of depolarization-induced and ryanodine-sensitive cytosolic Ca2+ elevation by synthetic carbocyclic analogs of cyclic ADP-ribose and their antagonistic effects in NG108-15 neuronal cells.

We synthesized analogs modified in the ribose unit (ribose linked to N1 of adenine) of cyclic ADP-ribose (cADPR), a Ca2+-mobilizing second messenger. The biological activities of these analogs were determined in NG108-15 neuroblastoma x glioma hybrid cells that were pre-loaded with fura-2 acetoxymethylester and subjected to whole-cell patch-clamp. Application of the hydrolysis-resistant cyclic ADP-carbocyclic-ribose (cADPcR) through patch pipettes potentiated elevation of the cytoplasmic free Ca2+ concentration ([Ca2+]i) at the depolarized membrane potential. The increase in [Ca2+]i evoked upon sustained membrane depolarization was significantly larger in cADPcR-infused cells than in non-infused cells and its degree was equivalent to or significantly greater than that induced by cADPR or beta-NAD+. 8-Chloro-cADPcR and two inosine congeners (cyclic IDP-carbocyclic-ribose and 8-bromo-cyclic IDP-carbocyclic-ribose) did not induce effects similar to those of cADPcR or cADPR. Instead, 8-chloro-cADPcR together with cADPR or cADPcR caused inhibition of the depolarization-induced [Ca2+]i increase as compared with either cADPR or cADPcR alone. These results demonstrated that our cADPR analogs have agonistic or antagonistic effects on the depolarization-induced [Ca2+]i increase and suggested the presence of functional reciprocal coupling between ryanodine receptors and voltage-activated Ca2+ channels via cADPR in mammalian neuronal cells.

Usefulness of preprocedural platelet aggregation to predict restenosis after percutaneous coronary intervention.

We investigated whether the assessment of small platelet aggregates before percutaneous coronary intervention (PCI) could predict restenosis after PCI. This was a prospective cohort study that enrolled 189 consecutive patients who had coronary artery disease. In multiple logistic regression analysis, higher levels of preprocedural small platelet aggregates were independently associated with restenosis after PCI. Measurement of small platelet aggregates may serve as a useful clinical variable for stratifying patients who present for PCI.