Biomedical subjects

Tsuyoshi Ito

Publications and source records attributed to Tsuyoshi Ito.

11 recordsLinked to original sources

PubMed2006

Effect of diesel exhaust particles on mRNA expression of viral and bacterial receptors in rat lung epithelial L2 cells.

Epidemiological studies have shown that particulate matter (PM) is associated with adverse respiratory health effects. Although infection in the respiratory organ is one of the most important health risks the association of infection with PM is not fully understood. As we had hypothesized that diesel exhaust particles (DEP), one of the major component of PM, may induce the expression of receptors for viruses and bacteria at invasion sites, we studied the effect of DEP on the mRNA expression of intercellular adhesion molecule-1 (ICAM-1), low-density lipoprotein (LDL) and platelet-activating factor (PAF) receptors, which are invasion sites of virus and bacteria, on rat lung epithelial cells. The real-time quantitative polymerase chain reaction (PCR) method was used for the evaluation. All of these mRNAs were up-regulated by 3, 10, and 30 microg/ml of DEP in a concentration-dependent manner. The up-regulation of each was associated with the mRNA expression of heme oxygenase-1 (HO-1), a marker of oxidative stress. Our present results show that DEP up-regulated the mRNA expression of viral and bacterial receptors. This up-regulation might be associated with DEP-induced oxidative stress. These results thus suggest that DEP may enhance the risk of pneumonia by increasing the density of bacterial and viral invasion sites in the lungs.

Air Pollutants↗

PubMed2006

A safer technique of aortic root replacement after aortic valve replacement.

Aortic root replacement after aortic valve replacement (AVR) is often complicated by bleeding around the aortic root, which increases the risk of morbidity and mortality, making it a technically challenging procedure. We describe a new technique of aortic root replacement designed to minimize bleeding around the aortic root. This surgical technique focuses on safe dissection and exposure of the aortic root to avoid inadvertent entry into the right atrium or right ventricle; on modifying the proximal anastomosis of the graft to the aortic annulus; and on performing a coronary artery reimplantation that achieves complete hemostasis at the suture lines. We performed aortic root replacement after AVR in four patients over a 4-year period, without encountering any bleeding around the aortic root.

Adult↗

PubMed2004

Endothelial integrity of ultrasonically skeletonized internal thoracic artery: morphological analysis with scanning electron microscopy.

OBJECTIVE: The skeletonized internal thoracic artery (ITA) has several advantages over a pedicled one in coronary artery bypass grafting (CABG). An ultrasonic scalpel makes ITA skeletonization easy and speedy, however, the ultrasonic energy that is transmitted to the artery itself can occasionally injure the endothelium. Therefore, the endothelial integrity of the ultrasonically skeletonized ITA is a major concern related to this technique. The purpose of this study is to assess the endothelial integrity of the ultrasonically skeletonized ITA. METHODS: We skeletonized the left ITA with an ultrasonic scalpel in nine patients who underwent CABG, and thereafter the terminal portion of this artery was subjected to a morphological study. The endothelial integrity of this artery was morphologically assessed using scanning electron microscopy, and the results were compared to that of the left ITA skeletonized with fine scissors. RESULTS: All ITA specimens showed a completely confluent endothelium, and no endothelial injury was observed by the scanning electron microscopic study. CONCLUSIONS: The skeletonization of the ITA with an ultrasonic scalpel had no deleterious effect on the endothelium. This morphological study confirmed the safety and the reliability of this technique, and we therefore recommend its clinical use in the skeletonization of the ITA for CABG.

Endothelium, Vascular↗

PubMed2003

Successful repair of left ventricular pseudoaneurysm after mitral reoperation under hypothermic circulatory arrest.

Successful repair of left ventricular (LV) pseudoaneurysm after mitral valve replacement (MVR) is uncommon, with delayed onset showing particularly high mortality. We report a case of delayed LV pseudoaneurysm onset after MVR reoperation. The patient had unique clinical symptoms, including coronary ischemia due to compression of the left main coronary artery by the aneurysm. Surgical repair was done using hypothermic circulatory arrest via left thoracotomy. The patient has experienced no cardiac events or pseudoaneurysm recurrence in the 7 years since surgery.

Aneurysm, False↗

PubMed2003

In vitro efficacy of l-asparaginase in childhood acute myeloid leukaemia.

To explore the potential efficacy of l-asparaginase treatment in acute myeloid leukaemia (AML) patients, we studied the in vitro resistance of French-American-British (FAB) subtypes of childhood AML to l-asparaginase using a methyl-thiazol-tetrazolium assay. We tested leukaemic cells obtained from 177 common acute lymphoblastic leukaemia (cALL) and 228 AML children at diagnosis. The median 70% lethal dose of l-asparaginase (LD70asp) (U/ml) was 0.46 in the cALL and 6.70 in the AML samples. The median LD70asp among each FAB subtype of AML was 0.76 (M0), 0.46 (M1), 10.00 (M2), 10.00 (M3), 1.18 (M4), 1.35 (M5) and 10.00 (M7). Type M3 samples had the highest LD70asp. The LD70asp of the M2 samples was significantly higher than that of the M1, M4 and M5 samples. When the LD70asp values were classified as low (0.016-0.159), intermediate (0.16-1.59) or high (1.6-10.00), the frequency of low, intermediate or high LD70asp among the M1 samples were similar to those among the cALL samples. In conclusion, cells from AML types M1, M4 and M5 were relatively sensitive to l-asparaginase, and M1 cells were as sensitive as those of cALL, suggesting that l-asparaginase treatment may be effective for these subtypes of AML.

Acute Disease↗

PubMed2003

[Utility of CT during aortography in depiction of the artery of Adamkiewicz and its origin: preliminary report].

The purpose of this study was to evaluate the feasibility of using CT during aortography with multidetector-row CT (MDCT) to depict the continuity of the Adamkiewicz artery and its origin. We performed CT during aortography in 4 patients with thoracoabdominal or descending aortic aneurysm, using multi-detector-row CT and portable DSA. The continuity of the Adamkiewicz artery and its origin were evaluated on multiplanar and curved planar reformation images and on cine-mode displays. In all patients, the Adamkiewicz artery was clearly visualized. The continuity of the Adamkiewicz artery and its origin were clearly visualized in 3 of 4 patients. In our preliminary study, CT during aortography with MDCT seemed to provide useful information about the Adamkiewicz artery and its origin for surgical candidates.

Aged↗

PubMed2002

Essential role of Gas6 for glomerular injury in nephrotoxic nephritis.

Growth-arrest specific gene 6 (Gas6) is a vitamin K-dependent growth factor for mesangial and epithelial cells. To investigate whether Gas6 is essential for progressive glomerular injury, we constructed Gas6(-/-) mice and examined the role of Gas6 in accelerated nephrotoxic nephritis (NTN), a model of progressive glomerulonephritis. We found less mortality and proteinuria in Gas6(-/-) mice than in wild-type mice following injection of nephrotoxic serum. Glomerular cell proliferation, glomerular sclerosis, crescent formation, and deposition of fibrin/fibrinogen in glomeruli were also reduced in Gas6(-/-) mice. Furthermore, administering Gas6(-/-) mice recombinant wild-type Gas6, but not Gas6 lacking a previously characterized N-terminal gamma-carboxyl group, induced massive proteinuria, glomerular cell proliferation, and glomerulosclerosis, comparable to responses seen in wild-type mice. These data indicate that Gas6 induces glomerular cell proliferation in NTN and suggest that this factor contributes to glomerular injury and the progression of chronic nephritis.

Animals↗

PubMed2002

Mitral annular reconstruction.

Mitral annular reconstruction using a pericardial patch was performed in 3 cases of atrioventricular disruption. This technique may be useful for atrioventricular disruption in cases of active endocarditis, redo valve replacement, left ventricular rupture after mitral valve replacement, and annular calcification.

Aged↗

PubMed2002

Novel point mutation in the cardiac transcription factor CSX/NKX2.5 associated with congenital heart disease.

The homeobox transcription factor CSX/NKX2.5, which is a vertebrate homologue of the Drosophila gene tinman, is essential for cardiac development. It is expressed in the early cardiac mesoderm and in heart muscle lineage throughout life. Homozygous deletion of CSX/NKX2.5 causes early embryonic lethality in mice because cardiac development is arrested at the linear heart tube stage. Heterozygous mutation of human CSX/NKX2.5 has been associated with various congenital heart diseases such as atrial septal defect (ASD), ventricular septal defect, tetralogy of Fallot, and tricuspid valve abnormalities, including Ebstein's anomaly. Additionally, CSX/NKX2.5 mutation causes atrioventricular (AV) conduction block with or without associated congenital heart diseases. Ten different heterozygous mutations have been already reported and a new point mutation, which is a C-to-A transition (Cys264ter) at nucleotide 901 of CSX/NKX2.5, results in the production of a truncated protein occurring COOH-terminal to the homeodomain of CSX/NKX2.5. The mutation was found in a patient with familial ASD and first-degree AV block; 4 members from 3 generations had secundum-type ASD and first-degree AV block.

Cysteine↗

PubMed2002

Coronary arteriovenous fistula presenting as chronic pericardial effusion.

In August 1998, the patient, a 75-year-old woman, was diagnosed with pericardial effusion (PE) during an investigation of cardiomegaly. The PE disappeared after the administration of diuretics, but in February 1999, shortness of breath and general fatigue developed, and PE was again present. Diagnostic pericardiocentesis revealed bloody fluid. Chest computed tomography revealed a markedly expanded and tortuous right coronary artery (RCA). Coronary angiography (CAG) confirmed a RCA-coronary sinus fistula, and there was a significant step-up of O2 saturation at the right atrium. Cardiac tamponade developed soon after CAG, so the patient underwent surgical closure of the CAVF. Although a bleeding point was not identified, the PE was disappeared after operation. Histopathologically, parts of the wall of the fistula were quite thin and erythrocytes and lymphocytes had infiltrated the pericardial space. The clinical course and the findings indicate that the CAVF caused chronic PE.

Aged↗

PubMedDate not supplied

MR imaging findings of adenomyosis: correlation with histopathologic features and diagnostic pitfalls.

Adenomyosis is a nonneoplastic condition, characterized by benign invasion of ectopic endometrium into the myometrium with hyperplasia of adjacent smooth muscle. The common symptoms include dysmenorrhea, menorrhagia, and abnormal uterine bleeding, but these do not allow diagnosis. Therefore, imaging plays an important role because establishment of the correct preoperative diagnosis is critical to avoid unnecessary intervention. Magnetic resonance (MR) imaging is a highly accurate noninvasive modality for diagnosis of adenomyosis, differentiation of adenomyosis from other gynecologic disorders, and planning of appropriate treatment. Although the typical MR imaging findings are well established, adenomyosis actually varies widely in terms of histopathologic features (adenomyosis with sparse glands), growth patterns (polypoid adenomyoma, adenomyotic cyst, and miniature uterus), responses to hormonal activity (tamoxifen, decidual changes), and responses to treatment (gonadotropin-releasing hormone agonist). The MR imaging findings of adenomyosis occasionally mimic those of uterine malignancy or ovarian cancer. Furthermore, malignancy occasionally develops in otherwise benign adenomyosis. Pitfalls in diagnosis of adenomyosis include myometrial contractions, leiomyoma, adenomatoid tumor, metastases, endometrial carcinoma, and endometrial stromal sarcoma. Knowledge of the various appearances of adenomyosis and the possible pitfalls in differential diagnosis help guide the determination of appropriate treatment options.

Adult↗