Effect of ethanol on mouse hepatitis virus-induced cytotoxicity

The effect of ethanol on cells infected with mouse hepatitis virus (MHV) was investigated. After MHV infection of competent cells, NCTC1469, ethanol was added to the culture at various concentrations, and the viability of cells was measured using 3-(4,5-dimethylthiazol-2yl)-2,5-diphenyltetrazolium bromide. To examine the possible involvement of the ethanol metabolite, acetaldehyde, alcohol dehydrogenase activity was measured in NCTC1469 cells. Ethanol alone did not show cytotoxicity against NCTC1469 cells at concentrations from 0.125% to 2%. After infection with MHV, the viability of cells decreased, and this decrease was further enhanced, dosedepependently, by the addition of ethanol. The activity of alcohol dehydrogenase in the cells was below the detectable level. The same phenomena were also demonstrated in cells infected with influenza virus andHerpes simplex virus. These results demonstrate that ethanol enhances MHV-mediated cytotoxicity; this exacerbation of cytotoxicity by ethanol is suggested to be an effect common to cytopathic virus-infected cells.     

Prolonged activation of hemostatic markers following conversion of atrial flutter to sinus rhythm.

BACKGROUND: It remains controversial whether prophylactic anticoagulation for embolism is required in patients with atrial flutter (AFL) prior to and following cardioversion as in patients with atrial fibrillation. To evaluate the potential prothrombotic state following cardioversion of AFL, concentrations of hemostatic markers were determined before and after conversion to sinus rhythm (SR). METHODS AND RESULTS: In 12 patients (mean age 68 years) with AFL who underwent transesophageal echocardiography in the plasma concentrations of markers for platelet activity (platelet factor 4 (PF4) and beta-thromboglobulin (beta-TG)), thrombotic status (thrombin-antithrombin III complex (TAT) and prothrombin fragments 1 and 2 (F1+2)) and fibrinolytic status (D-dimer and plasmin-alpha(2)-plasmin inhibitor complex (PIC)) were determined during AFL, and 3 days and 7 days after restoration of SR. Left atrial appendage (LAA) blood flow velocity was lower immediately after than before restoration of SR (29+/-11 vs 41+/-23 cm/s, p<0.05). Three patients developed left atrial spontaneous echo contrast immediately after restoration of SR. Although the concentrations of the markers of platelet activity did not change after restoration of SR, those of TAT and PIC increased 7 days after restoration of SR as compared with during AFL (p<0.05). CONCLUSIONS: AFL patients have a potential risk for thromboembolism after restoration of SR and therefore anticoagulation might be required in selected patients.     

Reprogramming of human postmitotic neutrophils into macrophages by growth factors

It is generally recognized that postmitotic neutrophils give rise to polymorphonuclear neutrophils alone. We obtained evidence for a lineage switch of human postmitotic neutrophils into macrophages in culture. When the CD15+CD14- cell population, which predominantly consists of band neutrophils, was cultured with granulocyte macrophage-colony-stimulating factor, tumor necrosis factor-alpha, interferon-gamma, and interleukin-4, and subsequently with macrophage colony-stimulating factor alone, the resultant cells had morphologic, cytochemical, and phenotypic features of macrophages. In contrast to the starting population, they were negative for myeloperoxidase, specific esterase, and lactoferrin, and they up-regulated nonspecific esterase activity and the expression of macrophage colony-stimulating factor receptor, mannose receptor, and HLA-DR. CD15+CD14- cells proceeded to macrophages through the CD15-CD14- cell population. Microarray analysis of gene expression also disclosed the lineage conversion from neutrophils to macrophages. Macrophages derived from CD15+CD14- neutrophils had phagocytic function. Data obtained using 3 different techniques, including Ki-67 staining, bromodeoxyuridine incorporation, and cytoplasmic dye labeling, together with the yield of cells, indicated that the generation of macrophages from CD15+CD14- neutrophils did not result from a contamination of progenitors for macrophages. Our data show that in response to cytokines, postmitotic neutrophils can become macrophages. This may represent another differentiation pathway toward macrophages in human postnatal hematopoiesis.     

Modification of pacing-induced alterations in diastolic properties of the regional myocardium by nifedipine in patients with coronary artery disease

Summary The effects of nifedipine on regional dysfunction during pacing-induced ischemia were studied in eight patients with coronary artery disease. Single-plane left ventriculograms were obtained using a high-fidelity micromanometer-tipped catheter in the control and post-pacing periods both before and after pretreatment with nifedipine. All patients developed typical anginal pain during pacing tachycardia before but not after pretreatment with nifedipine. After pacing, left ventricular end-diastolic pressure (EDP) increased from 10±5 (SD) mmHg to 23±9 mmHg (P<0.01) with enlargement of the end-diastolic volume (EDV). The ejection fraction (EF) was reduced from 66±10% to 54±13% (P<0.05). With nifedipine, a post-pacing increase in EDP was markedly attenuated together with a 17% reduction in left ventricular systolic pressure (P<0.05).The regional myocardial function was expressed by a radial coordinate system with its origin at the center of gravity of the end-diastolic contour. Two representative radial grids for normal and ischemic segments were selected. In the normal segment, the end-diastolic length (EDL) was augmented by 14% (from 26.1±5.2 mm to 29.7±6.1 mm,P<0.01) associated with a 23% increase in stroke excursion (P<0.05) with pacing stress. In the ischemic segments, EDL remained unchanged in the post-pacing beat but stroke excursion was significantly reduced (from 11.4±5.2 mm to 4.3±1.8 mm,P<0.01). After pretreatment with nifedipine, the responses of the regional myocardium to the same pacing stress were markedly reduced; the EDL of the control segment was 27.4±4.6 mm with equally augmented stroke excursion. EDL of the ischemic segment remained unchanged but post-pacing deterioration of segment shortening was remarkably improved (8.7±3.3 mm,P<0.05). With pacing stress before nifedipine, the control segment moved up to the higher portion of the single curve. In the ischemic segment, the diastolic pressure became higher at any given length and the pressure length curve clearly shifted upward, indicating regional alteration of the diastolic property. After nifedipine, this upward shift of the regional myocardial pressure-length relationship was markedly attenuated.Thus, we conclude that nifedipine favorably modifies the symptomatic and hemodynamic responses to transient ischemia due to pacing stress largely mediated by selective improvement of the ischemic segment.     

So-called "ampulla" cardiomyopathy associated with coronary vasospasm compared with acute myocardial infarction showing similar abnormal left ventricular wall motion: two case reports

So-called "ampulla" cardiomyopathy is characterized by transient abnormal left ventricular wall motion showing hypokinesia around the apical area and hyperkinesia at the basal area, without any detectable coronary lesion. We recently treated a patient with "ampulla" cardiomyopathy (Case 1) and a patient with acute myocardial infarction showing similar abnormal left ventricular wall motion (Case 2). A 75-year-old female (Case 1) presented with "ampulla" cardiomyopathy without coronary lesion. Vasospasm was induced at segment 8 on the left anterior descending (LAD) coronary artery by intracoronary administration of acetylcholine. A 58-year-old male (Case 2) presented with acute myocardial infarction due to occlusion at segment 8 and underwent successful coronary reperfusion therapy by direct percutaneous transluminal coronary angioplasty. Both Case 1 and Case 2 revelaed similar abnormal left ventricular wall motion, with hypokinesia around the apical area and hyperkinesia at the basal area by echocardiography, in the acute phase. Furthermore, these two patients showed elevated ST segment at both anterior and inferior leads by electrocardiography, and markedly reduced uptake of beta-methyl-p-iodophenyl-pentadecanoic acid around the apical area in the acute phase by scintigraphy. Interestingly, the LAD perfused a relatively wide area including the anterior, apical and part of the inferior area of the left ventricle in both patients by coronary angiography. The abnormal wall motion of Case 1 disappeared 4 weeks after onset, but that of Case 2 did not disappear. Although the diagnoses of Case 1 and Case 2 were different, abnormal wall motion of these cases might be due to myocardial ischemia due to distal LAD lesion. "Ampulla" cardiomyopathy might develop from transient myocardial ischemia induced by coronary vasospasm at the distal LAD which perfuses a relatively wide area.     

Verruciform xanthoma in close association with isolated epidermolytic acanthoma: a case report and review of the Japanese dermatological literature

A 52-year-old man presented to our department with a scrotal skin nodule, first noted as a papule two to three years previously. The nodule was red and pedunculated with a granular surface and a diameter of 10 mm. Three red papules were scattered around the nodule. Histopathologic examination of the nodule showed epidermal papillary hyperplasia, collections of foam cells in the papillary dermis, and a dense infiltration of inflammatory cells into all dermal layers. In addition, granular degeneration was seen in the pedunculated lesion of the nodule free from the foam cells. Microscopic examination of the red papules also showed granular degeneration. The patient was diagnosed with verruciform xanthoma associated with isolated epidermolytic acanthoma. This is the first report of these two lesions occurring at the same site on the scrotum.     

DNMT1 and DNMT3b silencing sensitizes human hepatoma cells to TRAIL‐mediated apoptosis via up‐regulation of TRAIL‐R2/DR5 and caspase‐8

DNA methylation plays a critical role in chromatin remodeling and gene expression. DNA methyltransferases (DNMTs) are hypothesized to mediate cellular DNA methylation status and gene expression during mammalian development and in malignant diseases. In this study, we examined the role of DNA methyltransferase 1 (DNMT1) and DNMT3b in cell proliferation and survival of hepatocellular carcinoma (HCC) cells. Gene silencing of both DNMT1 and DNMT3b by targeted siRNA knockdown reduces cell proliferation and sensitizes the cells to tumor necrosis factor‐related apoptosis‐inducing ligand (TRAIL)‐mediated cell death. The proapoptotic protein caspase‐8 demonstrated promoter hypermethylation in HCC cells and was up‐regulated by knockdown of DNMT1 and DNMT3b both at mRNA and protein levels. In addition, death receptor TRAIL‐R2/DR5 (TRAIL receptor 2/death receptor 5) did not exhibit promoter hypermethylation in HCC cells but was also up‐regulated by knockdown of DNMT1 and DNMT3b both at mRNA and protein levels. Consistent with this observation, the combined transfection of DNMT1‐siRNA plus DNMT3b‐siRNA enhanced formation of the TRAIL‐death‐inducing signaling complex formation in HCC cells. In conclusion, our data suggest that DNA methylation of specific genomic regions maintained by DNMT1 and DNMT3b plays a critical role in survival of HCC cells, and a simultaneous knockdown of both DNMT1 and DNMT3b may be a novel anticancer strategy for the treatment of HCC. (Cancer Sci 2010)