Very Late Stent Thrombosis after Discontinuation of Antiplatelet Agents during Anticoagulation Therapy in a Patient with Peri-stent Contrast Staining after Implantation of a Second-generation Drug-eluting Stent

A 54-year-old man was admitted to our hospital due to intermittent chest pain. He had a history of acute myocardial infarction, and peri-stent contrast staining had been observed at the stent implantation site. The patient previously underwent anticoagulation therapy for left ventricular thrombus and antiplatelet therapy to prevent stent thrombosis. More than one year after implantation of a drug-eluting stent, antiplatelet drugs were discontinued, and anticoagulant alone was prescribed according to the guidelines, which resulted in very late stent thrombosis. The risks of both bleeding and thrombosis must be fully considered when deciding whether or not to discontinue antiplatelet therapy during anticoagulation therapy.     

Comparative study of functional outcomes of three laparoscopic intestinal surgical procedures

ObjectivesLaparoscopic abdominal surgery (LS) has been prevailing over open surgery (OS). However, its functional outcomes in the aging generation have not been sufficiently examined. We compared changes in physical status and earlier resumption of oral intake between LS and OS.MethodsUsing the Japanese administrative database, we matched variables affecting LS and compared them between LS and OS patients. During the 6-month period from July to December of 2006–2010, we examined the data from data from surviving patients of ≥15 year old who underwent isolated gastrectomy, colectomy, or anterior resection. Functional status was estimated by the Barthel index (BI) at admission and discharge. Outcomes were postoperative complications, BI deterioration, change in BI, and day of recommencing postoperative oral intake.ResultsWe identified 30,763 gastrectomies (laparoscopic: 7297), 31,958 colectomies (laparoscopic: 9364), and 12,545 anterior resections (laparoscopic: 4351). Variation in LS indications was observed in patient and hospital mixes. Among the paired-matched gastrectomy, colectomy, and anterior resection groups, LS was associated with fewer complications and earlier recovery of postoperative oral intake. Laparoscopic anterior resection (LAR) and colectomy were associated with less frequent BI deterioration. Longer operative time was associated with more complications, which then influenced BI deterioration in patients who underwent anterior resection.ConclusionsShorter operative time for LAR was associated with less functional deterioration than for laparoscopic gastrectomy and colectomy. Physicians should consider the appropriate indications for LS by concurrently avoiding unnecessary longer operations and their associated complications. More investment in teaching the skills necessary for LAR is recommended.     

Infarct Size Limitation by Bradykinin Receptor Activation Is Mediated by the Mitochondrial But Not by the Sarcolemmal KATP Channel

Earlier studies have shown that activation of bradykinin B₂ receptor triggers protein kinase C (PKC)-mediated cardioprotective mechanism in ischemic preconditioning (PC). In the present study, we examined whether the effector in this B₂-receptor triggered pathway of PC is the ATP sensitive potassium (K_ATP) channel in the mitochondria (mito-K_ATP channel) or K_ATP channel in the sarcolemma (sarc-K_ATP channel). Isolated rabbit hearts were perfused with modified Krebs-Henseleit buffer in a Langendorff mode, and regional myocardial ischemia was induced by occluding a left coronary artery for 30 min and then reperfusing for 2 hours. Infarct size was determined by triphenyltetrazolium chloride staining and expressed as a percentage of area at risk (% IS/AR). Infusion of bradykinin (500 nmol/L) for 15 min prior to ischemia significantly reduced % IS/AR from 37.4 ± 2.9 (SE) of the untreated controls to 12.0 ± 3.3%. This protective effect of bradykinin was completely abolished by coinfusion of 5-hydroxydecanoate (5-HD, 50 mol/L), a selective mito-K_ATP channel blocker (% IS/AR = 44.2 ± 6.4). In contrast, a high dose of HMR1098 (20 mol/L), which is a newly developed sarc-K_ATP channel selective blocker with IC₅₀ of 0.6 mol/L, failed to modify the infarct size limitation by preischemic infusion of bradykinin (% IS/AR = 11.7 ± 3.4). Neither 5-HD nor HMR1098 alone modified infarct size (% IS/AR = 37.8 ± 3.8 and 35.1 ± 6.2, respectively). These results suggest that opening of the mito-K_ATP channel but not the sarc-K_ATP channel is involved in infarct size limitation by a mechanism triggered by bradykinin B₂ receptor activation.     

Calcium mobilization in liver transplantation graft with warm ischemia

The influence of warm ischemia on calcium mobilization in liver transplantation was investigated. Twenty-four porcine orthotopic liver transplantations were performed by a temporary portal arterialization technique. Swine were divided into three groups according to warm ischemia time; I (0 min,n=9), II (30 min,n=8), and III (60min,n=7). Ionized calcium was measured in arterial and hepatic venous blood, in initial perfusate, and in initial perfused blood. In group I, all the pigs survived, while in group III all succumbed. In group II, four survived and four died. Ionized calcium level in influx showed no differences, but the level in the initial perfusate in group I was significantly higher than that in group III. The level in the initial perfused blood in group I was significantly higher than levels in groups II and III. Retrospective analysis in group II showed that ionized calcium value in the initial perfused blood in the survivors was significantly higher than that in the non-survivors. A substantial amount of ionized calcium accumulated after revascularization in the graft loaded with warm ischemia, and, in group II, significantly more ionized calcium accumulated in the non-survivors.     

Myelodysplastic syndrome (MDS)-associated inhibitory activity on haemopoietic progenitor cells

We studied MDS-associated inhibitory activity, which inhibited colony formation in vitro of granulocyte-macrophage progenitors (CFU-GM). Macrophages obtained from MDS bone marrow mononuclear cells (BM-MNC) when pretreated with granulocyte-macrophage colony stimulating factor (GM-CSF) suppressed the growth of normal CFU-GM. These macrophages were designated as 'MDS-derived inhibitory macrophages'. Media conditioned by MDS-derived inhibitory macrophages (MDS-CM) also suppressed the growth of normal CFU-GM. In the MDS-CM, high levels of prostaglandin E2 (PGE2) and ferritin were found. However, MDS-CM did not contain detectable levels of tumour necrosis factor (TNF) or gamma-interferon (gamma-IFN). Antiserum against human placental ferritin and/or against PGE2 blocked the haemopoietic inhibitory activity to some extent. These results suggest that inhibitory macrophages may be responsible for the suppression of granulopoiesis in patients with MDS and that the suppression may be mediated by soluble factors including PGE2 and ferritin.     

Myocardial bridging increases the risk of coronary spasm

BACKGROUND: Myocardial bridging (MB) has been associated with cardiac events. Whether coronary spasm is one factor contributing to those events is unknown. HYPOTHESIS: This study investigated whether the likelihood of coronary spasm is increased in patients with MB. METHODS: A spasm-provocation test was performed by infusing acetylcholine into the left coronary artery in 114 Japanese patients with chest pain. The test result was defined as positive when the diameter of the coronary artery was reduced by > or = 50% and ST-segment changes were documented. Myocardial bridging was defined as a > 15% reduction in coronary arterial diameter during systole after intracoronary injection of nitroglycerin. RESULTS: Myocardial bridging was identified in 41 patients (36%) and was located in the mid-segment of the left anterior descending coronary artery (LAD) in all patients. Patients with MB experienced coronary spasm more frequently than patients without MB (MB+: 73%; MB-: 40%, p = 0.0006). Furthermore, among patients with a positive spasm-provocation test, coronary spasm occurred more frequently in the mid-segment of the LAD in patients with MB than in those without MB (MB+: 73%; MB-: 45%, p = 0.0259). Multivariate regression analysis demonstrated that MB was a predictor of coronary spasm (odds ratio: 3.478, p = 0.0088). CONCLUSIONS: These results suggest that MB increases the risk of coronary spasm and that coronary spasm may be the proximate etiology of cardiac events associated with MB.     

Carbon fibre reinforced cellulose-based polymers: intensifying interfacial adhesion between the fibre and the matrix

Interfacial interactions governing the interfacial adhesion between cellulose propionate and carbon fibre surface are placed under scrutiny to pave the way towards the development of green cellulose-based carbon fibre reinforced polymers. A range of molecular entities are deposited on the surface by initially grafting aromatic structures with appropriate functions via diazonium species followed by further derivatization of these entities. Cellulose propionate was also bound covalently to the surface via a tosylated derivative invoking its facile nucleophilic displacement reaction with surface-grafted amino functions. Significant increase in interfacial shear strength was obtained for the cellulose propionate-grafted carbon fibre composite as well as for the 4-(aminomethyl)benzene-functionalized sample, in the latter case possible hydrogen bonding took place with the cellulose propionate matrix. Furthermore, the positive effect of a highly lipophilic and yet compact –CF₃ substituent was also noted. In order to let the grafted structure efficiently penetrate into the matrix, steric factors, lipophilicity and potential secondary interactions should be considered. It needs to be pointed out that we provide the first synthetic strategy to covalently bind cellulose derivatives to a largely graphitic surface and as such, it has relevance to carbonaceous materials being applied in cellulose-based innovative materials in the future.

Interfacial adhesion of a cellulose propionate/carbon fibre composite is tailored providing a synthetic strategy to bind cellulose derivatives to graphitic surfaces.     

Estimated Daily Intake and Seasonal Food Sources of Quercetin in Japan

Quercetin is a promising food component, which can prevent lifestyle related diseases. To understand the dietary intake of quercetin in the subjects of a population-based cohort study and in the Japanese population, we first determined the quercetin content in foods available in the market during June and July in or near a town in Hokkaido, Japan. Red leaf lettuce, asparagus, and onions contained high amounts of quercetin derivatives. We then estimated the daily quercetin intake by 570 residents aged 20–92 years old in the town using a food frequency questionnaire (FFQ). The average and median quercetin intakes were 16.2 and 15.5 mg day⁻¹, respectively. The quercetin intakes by men were lower than those by women; the quercetin intakes showed a low correlation with age in both men and women. The estimated quercetin intake was similar during summer and winter. Quercetin was mainly ingested from onions and green tea, both in summer and in winter. Vegetables, such as asparagus, green pepper, tomatoes, and red leaf lettuce, were good sources of quercetin in summer. Our results will help to elucidate the association between quercetin intake and risks of lifestyle-related diseases by further prospective cohort study and establish healthy dietary requirements with the consumption of more physiologically useful components from foods.