Yoshihiro Ikura

Dr. Yoshihiro Ikura

orcid

Research Focus & Metrics

Academic Career Length

38Years (1989-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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3 December 2002 in Circulation
Verified
Journal Article
Closed access
TNTakahiko Naruko
Takahiko Naruko
MUMakiko Ueda
Makiko Ueda
KHKazuo Haze
Kazuo Haze
AWAllard C. van der Wal
Allard C. van der Wal
CLChris M. van der Loos
Chris M. van der Loos
ABAnton E. Becker
Anton E. Becker
Background— Neutrophils in unstable atherosclerotic lesions have not received much consideration, despite accumulating evidence suggesting a link between systemic inflammation and acute coronary syndromes. Methods and Results— Coronary artery segments were obtained at autopsy from 13 patients with acute myocardial infarction (AMI); 8 had a ruptured and 5 an eroded plaque. Patients (n=45) who had died of noncardiovascular diseases served as reference. Atherectomy specimens were obtained from 35 patients with stable angina pectoris (SAP) and from 32 patients with unstable angina pectoris (UAP). Antibodies against CD66b, elastase, myeloperoxidase, and CD11b identified neutrophils; CD10 identified neutral endopeptidase (NEP). CD66b-positive and NEP-positive neutrophils were counted and expressed as a number per square millimeter of tissue. All specimens with plaque rupture or erosion showed distinct neutrophil infiltration; the number did not differ between ruptured and eroded plaques. However, the number of NEP-positive neutrophils was significantly higher ( P <0.0001) in ruptured plaques than in eroded plaques. UAP patients showed neutrophils in 14 of 32 culprit lesions; in SAP only 2 of 35 lesions contained neutrophils. The number of neutrophils and NEP-positive cells in patients with UAP was significantly higher (neutrophils, P <0.0005; NEP-positive cells, P <0.005) than in patients with SAP. Conclusions— The observations suggest that neutrophil infiltration is actively associated with acute coronary events. The high number of NEP-positive neutrophils in ruptured plaques, compared with eroded plaques, may reflect differences in the underlying pathophysiological mechanisms.

1 March 2004 in Arteriosclerosis, Thrombosis, and Vascular Biology
Verified
Journal Article
Closed access
PDF file
MOMasayuki Ogami
Masayuki Ogami
Yoshihiro IkuraYoshihiro Ikura
Yoshihiro Ikura
MOMasahiko Ohsawa
Masahiko Ohsawa
TMToshihiko Matsuo
Toshihiko Matsuo
SKSoichiro Kayo
Soichiro Kayo
MUMakiko Ueda
Makiko Ueda
Background— Increased cell turnover in response to injury is considered to be important in the development of atherosclerotic plaques. Telomere shortening has been shown to be associated with cell turnover. We assessed the telomere length of human coronary endothelial cells to clarify whether there is a relationship between telomere shortening and coronary artery disease (CAD). Methods and Results— Coronary endothelial cells were obtained from 11 patients with CAD who underwent autopsy and 22 patients without CAD who underwent autopsy by scraping off the luminal surface of coronary arteries. DNA extracted from the endothelial cells were blotted and hybridized with telomere-specific oligonucleotide ([TTAGGG] 4 ). The hybridization signal intensity, which represented telomeric DNA content, was standardized with centromeric DNA content (T/C ratio) to estimate telomere length. The T/C ratios were significantly smaller ( P <0.0001) in CAD patients than in age-matched non-CAD patients (CAD patients, 0.462±0.135; non-CAD patients, 1.002±0.212). In 6 individual CAD patients, the T/C ratio at the atherosclerotic lesion was significantly smaller ( P <0.05) than that at the non-atherosclerotic portion. Conclusions— These findings suggest that focal replicative senescence and telomere shortening of endothelial cells may play a critical role in coronary atherogenesis and CAD.

1 October 2010 in Journal of Hepatology
Verified
Journal Article
Closed access
SCStephen Caldwell
Stephen Caldwell
Yoshihiro IkuraYoshihiro Ikura
Yoshihiro Ikura
DDDaniela Dias
Daniela Dias
KIKosuke Isomoto
Kosuke Isomoto
AYAkito Yabu
Akito Yabu
JRJan A. Redick
Jan A. Redick

1 January 2008 in Journal of Thrombosis and Haemostasis
Verified
Journal Article
Open access
PDF file
PNP. G. Northup
P. G. Northup
VSV. Sundaram
V. Sundaram
MFM. B. Fallon
M. B. Fallon
KRK. R. Reddy
K. R. Reddy
RBR. A. Balogun
R. A. Balogun
SCS. H. Caldwell
S. H. Caldwell
A complex balance exists between endogenous procoagulants and the anticoagulant system in liver disease patients. Hypercoagulable events occur in cirrhosis patients despite the well-known bleeding diathesis of liver disease. These events may be clinically evident, such as in portal vein thrombosis or pulmonary embolism, but these conditions may also be a silent contributor to certain disease states, such as portopulmonary hypertension or parenchymal extinction with liver atrophy as well as thrombosis of extracorporeal circuits in dialysis or liver assist devices. Moreover, liver disease-related hypercoagulability may contribute to vascular disease in the increasingly common condition of non-alcoholic fatty liver disease. Despite the incidence of these problems, there are few widely accessible and practical laboratory tests to evaluate the risk of a hypercoagulable event in cirrhosis patients. Furthermore, there is little research on the use of commonly accepted anticoagulants in patients with liver disease. This article is a result of an international symposium on coagulation disorders in liver disease and addresses several areas of specific interest in hypercoagulation in liver disease. Critical areas lacking clinical information are highlighted and future areas of research interest are defined with an aim to foster clinical research in this field.

1 March 2007 in The American Journal of Pathology
Verified
Journal Article
Closed access
KOKohji Otogawa
Kohji Otogawa
KKKohji Kinoshita
Kohji Kinoshita
HFHideki Fujii
Hideki Fujii
MSMasahide Sakabe
Masahide Sakabe
RSRyoko Shiga
Ryoko Shiga
NKNorifumi Kawada
Norifumi Kawada

22 February 2006 in Hepatology
Verified
Journal Article
Open access
PDF file
Yoshihiro IkuraYoshihiro Ikura
Yoshihiro Ikura
MOMasahiko Ohsawa
Masahiko Ohsawa
TSTakehisa Suekane
Takehisa Suekane
HFHiroko Fukushima
Hiroko Fukushima
HIHiroyuki Itabe
Hiroyuki Itabe
MUMakiko Ueda
Makiko Ueda
Nonalcoholic steatohepatitis/nonalcoholic fatty liver disease is considered to be a hepatic manifestation of various metabolic disorders. However, its precise pathogenic mechanism is obscure. Oxidative stress and consequent lipid peroxidation seem to play a pivotal role in disease progression. In this study, we analyzed the localization of oxidized phosphatidylcholine (oxPC), a lipid peroxide that serves as a ligand for scavenger receptors, in livers of patients with this steatotic disorder. Specimens of non-alcoholic fatty liver disease (15 autopsy livers with simple steatosis and 32 biopsy livers with steatohepatitis) were examined via immunohistochemistry and immunoelectron microscopy using a specific antibody against oxPC. In addition, scavenger receptor expression, hepatocyte apoptosis, iron deposition, and inflammatory cell infiltration in the diseased livers were also assessed. Oxidized phosphatidylcholine was mainly localized to steatotic hepatocytes and some macrophages/Kupffer cells. A few degenerative or apoptotic hepatocytes were also positive for oxPC. Immunoelectron microscopy showed oxPC localized to cytoplasmic/intracytoplasmic membranes including lipid droplets. Steatotic livers showed enhanced expression of scavenger receptors. The number of oxPC cells was correlated with disease severity and the number of myeloperoxidase-positive neutrophils, but not with the degree of iron deposition. In conclusion , distinct localization of oxPC in liver tissues suggest that neutrophil myeloperoxidase-derived oxidative stress may be crucial in the formation of oxPC and the progression of steatotic liver disease. (Hepatology 2006;43:506–514.)