Biomedical subjects

Kozo Fujii

Publications and source records attributed to Kozo Fujii.

4 recordsLinked to original sources

PubMed2004

Effects of angiotensin II type 1 receptor antagonist on smooth muscle cell phenotype in intramyocardial arteries from spontaneously hypertensive rats.

To clarify the precise mechanisms involved in the reduced coronary flow reserve in hypertension, we compared the effects of the angiotensin II type 1 (AT1) receptor antagonist FK-739 with those of the angiotensin-converting enzyme (ACE) inhibitor enalapril for 6 weeks on the smooth muscle (SM) cell phenotype in intramyocardial arteries from male Wistar-Kyoto rats (WKY) and spontaneously hypertensive rats (SHR). Compared with WKY, SHR showed a significant increase in left ventricular (LV) hypertrophy and fibrosis, blood pressure (BP), and vascular remodeling of the intramyocardial arteries, and a significant decrease in endothelial NO synthase and the contractile-type myosin heavy chain isoform SM2 of the intramyocardial arteries as well as calponin 1 and GATA-6. In the hearts of SHR, both drugs equivalently and significantly reduced BP, which was still significantly higher than that in the WKY groups, and also reduced LV hypertrophy and fibrosis, whereas endothelial NO synthase was significantly restored. Although both drugs showed little effect on the vascular remodeling of the intramyocardial arteries in the SHR hearts, FK-739, but not enalapril, significantly restored SM2 and GATA-6 in the SHR hearts to the same levels as those of the vehicle WKY group. The effects of the two drugs on these indices were not observed in the three WKY hearts. Thus, the AT1 receptor antagonist may modulate the SM cell phenotype toward the contractile-type more effectively than the ACE inhibitor before the morphological changes occur in the intramyocardial arteries of the SHR hearts.

Actins↗

PubMed2004

[A case of microscopic polyangitis presented with acute pericarditis].

We report a case of microscopic polyangitis presenting with acute pericarditis. A 75-year-old man, who had recurrent acute pericarditis, was referred by a cardiologist because of bilateral infiltrates in the chest radiograph, microhematuria and progressive renal failure. The test for MPO-ANCA was positive. Transbronchial and renal biopsies were compatible with microscopic polyangitis, showing alveolar hemorrhage and crescentic glomerulonephritis. After 3 days, intravenous methylpredonisolone was given, followed by oral prednisolone 40 mg/day, and the patient's radiographic infiltrates cleared and renal dysfunction improved. However, he died from opportunistic infection 109 days after the onset of treatment.

Acute Disease↗

PubMed2003

Proteasome-dependent decrease in Akt by growth factors in vascular smooth muscle cells.

Akt is activated by growth factors to regulate various aspects of vascular smooth muscle cell function. Platelet-derived growth factor (PDGF) and insulin-like growth factor-1 activated Akt in vascular smooth muscle cells with a rapid reduction of total Akt protein that lasted for several hours. The downregulation of Akt required phosphatidylinositol 3-kinase activity, but not intrinsic Akt activity. The downregulation of Akt was abrogated by MG-132, a proteasome inhibitor, but not by inhibitors of calpain or cathepsins. Akt was found in ubiquitin immune complex after PDGF treatment. Proteasome-dependent degradation of Akt may provide a counter-regulatory mechanism against overactivation of Akt.

Animals↗

PubMed2002

Visualization of jet flows over a plate by pressure-sensitive paint experiments and comparison with CFD.

Flow fields created by underexpanded sonic jets impinging on an inclined flat plate were studied experimentally using the pressure sensitive paint (PSP) measurement technique. The measurement system and some representative results are presented here. Two binders, thin-layer chromatography (TLC) plates and anodized aluminum (A-A) plates were tested with bathophen ruthenium chloride as a luminophore. The results show that both the binders can be used. TLC plates are preferable because their luminescent intensity is almost twice that of the A-A plates. Quantitative measurements require accurate temperature calibration. A preliminary effort to elucidate the flow structure by combining the PSP results with a computer simulation of the same flow field is presented. Although good agreement is obtained between the experimental and numerical results, future quantitative comparisons are necessary to yield a useful tool in the analysis of the jet-plate interaction flows.

Aluminum↗