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Biomedical subjects

J Kondo

Publications and source records attributed to J Kondo.

At least 19 recordsLinked to original sources

Relation of a common methylenetetrahydrofolate reductase mutation and plasma homocysteine with intimal hyperplasia after coronary stenting.

BACKGROUND: Hyperhomocysteinemia has been identified as an independent risk factor for coronary artery disease. Recent studies have shown that a common mutation (nucleotide 677 C-->T) in the methylenetetrahydrofolate reductase (MTHFR) gene may contribute to mild hyperhomocysteinemia and, therefore, to the incidence of coronary artery disease. No information exists, however, regarding the association between the mutation of the MTHFR gene or plasma homocysteine levels and morphological analysis of coronary atherosclerosis using intravascular ultrasound. METHODS AND RESULTS: To examine the potential influence of MTHFR genotype and homocysteine on coronaryarteries morphologically, we screened 62 patients with 65 lesions that were treated with 93 Palmaz-Schatz stents. The plasma homocysteine levels in the patients with the TT genotype were not significantly higher than those in the patients with non-TT (CC+CT) genotypes (13.1 +/- 5.5 versus 11.5 +/- 3.1 mmol/L, P=0.16). Angiographic analysis showed that the percent diameter stenosis in the patients with the TT genotype was significantly greater than that in those with non-TT genotypes (43.7 +/- 17.8% versus 29.0 +/- 22.0%, P=0.015). Intravascular ultrasound analysis showed that the TT genotype was significantly associated with greater intimal hyperplasia area (5.70 +/- 1.94 versus 3.72 +/- 1.38 mm2, P=0.001). In multiple stepwise regression analysis, the number of the T alleles was the only independent predictor of intimal hyperplasia after intervention (r2=0.21, P=0.004). CONCLUSIONS: The homozygous mutant genotype of the MTHFR gene may increase the risk of in-stent restenosis more than does the normal homozygous or heterozygous genotype.

Alleles↗

Effect of quinapril on intimal hyperplasia after coronary stenting as assessed by intravascular ultrasound.

We studied whether angiotensin-converting enzyme inhibition with quinapril treatment can prevent in-stent restenosis after successful implantation of Palmaz-Schatz stents. Intravascular ultrasound study, but not quantitative coronary angiography analysis, revealed that quinapril treatment significantly prevented the loss of both minimal lumen cross-sectional area and lumen volume in stents, in addition to reducing the increase in intimal hyperplasia volume.

Aged↗

Acetyl-CoA synthetase 2, a mitochondrial matrix enzyme involved in the oxidation of acetate.

Using peptide sequences derived from bovine cardiac acetyl-CoA synthetase (AceCS), we isolated and characterized cDNAs for a bovine and murine cardiac enzyme designated AceCS2. We also isolated a murine cDNA encoding a hepatic type enzyme, designated AceCS1, identical to one reported recently (Luong, A., Hannah, V. C., Brown, M. S., and Goldstein, J. L. (2000) J. Biol. Chem. 275, 26458-26466). Murine AceCS1 and AceCS2 were purified to homogeneity and characterized. Among C2-C5 short and medium chain fatty acids, both enzymes preferentially utilize acetate with similar affinity. The AceCS2 transcripts are expressed in a wide range of tissues, with the highest levels in heart, and are apparently absent from the liver. The levels of AceCS2 mRNA in skeletal muscle were increased markedly under ketogenic conditions. Subcellular fractionation revealed that AceCS2 is a mitochondrial matrix enzyme. [(14)C]Acetate incorporation indicated that acetyl-CoAs produced by AceCS2 are utilized mainly for oxidation.

Acetate-CoA Ligase↗

Midterm results of stent-graft repair for thoracic aortic aneurysms: computed tomographic evaluation.

Midterm observation of endovascular surgery using a fabric-covered stent graft for thoracic aortic aneurysms is discussed with postoperative follow-up findings based on regularly performed thoracic computed tomography (CT). From 1996 to 1999, 20 patients with thoracic aortic aneurysm underwent stent-graft placement in our hospital. One year follow-up CT results after placement were obtained for 17 patients. The CT scans found that there were both thrombosis and size reduction of aneurysm in 8 patients (46%), thrombosis without size reduction in 2 (13%), a new ulcerlike projection (ULP) in 3 (19%), persistent minor endoleakage in 2 (13%), a new endoleak in 1 (6%), and a recurrent endoleak from intercostal arteries in 1 (6%). The new ULP formation seemed to be a peculiar problem stemming from an intimal injury caused by edges of the stent. Therefore, we recently adopted a new spiral stent instead of the previous stent to avoid the injury. The new endoleak suggested that aneurysmal thrombosis without size reduction could cause the aneurysm to develop recurrent endoleaks. From these findings, we concluded that midterm observation of stent-graft repair for thoracic aortic aneurysms did not give satisfactory results. In order to improve the results of endovascular surgery using stent-grafts, we need to develop safer stent grafts with a reliable design to prevent endoleaks and to avoid intimal injury of the aorta. We also hope to develop effective technologies that can accelerate organization of thrombus in the aortic aneurysm after stent-graft placement.

Adult↗

X-ray analyses of d(GCGAAAGC) and d(GXGAAAGCT), where X = 2'-deoxy-5-iodocytidine.

DNA fragments containing a sequence d(GCGAAAGC) are known to be highly thermostable. To investigate the structural basis for such a specific property, crystallographic studies of the DNA octamer and a nanomer d(GXGAAAGCT) (X = 2'-deoxy-5-iodocytidine) have been performed. The present higher resolution X-ray analyses have shown that both DNA oligomers are stabilized respectively to form a zipper-type duplex homodimer. PAGE of these oligomers, however, indicates that they are monomeric even when their crystals were dissolved at room temperature.

Base Sequence↗

X-ray analysis of d(GCGAACGC); intra-duplex and inter-duplex hand-in-pocket motifs.

The structure of DNA octamer with the sequence d(GCGAACGC) has been determined by the X-ray crystallography to investigate the specific DNA structural motifs that are useful for designing various functional DNA molecules. Two kinds of interaction motifs for the bulged out adenosine residues have been found. One is an intra-duplex and the other is an inter-duplex hand-in-pocket motif. These interactions consist of the novel A:G pairs that have never been found so far in any crystal and solution studies on DNA molecules.

Base Sequence↗

Corrected transposition of the great arteries diagnosed in an 84-year-old woman.

Corrected transposition of the great arteries without associated cardiac anomalies is a rare cardiac malformation. Few patients with this anomaly survive beyond 50 years of age because of systemic ventricular dysfunction or development of AV valvular regurgitation or conduction disturbance. We describe an autopsied, uncomplicated corrected transposition of the great arteries case in which the patient died at 84 years of age. We believe this patient to be the longest surviving corrected transposition of the great arteries associated person in the world.

Aged↗

[Usefulness of combination therapy of hybrid thrombolysis followed by back-up percutaneous transluminal coronary angioplasty in patients with acute myocardial infarction].

OBJECTIVES: Conventional thrombolytic therapy for acute myocardial infarction is effective for early reperfusion but has the disadvantage of a higher rate of bleeding complications. The purpose of this study is to elucidate efficacy and safety of a combined approach using a bolus injection of low dose of mutant tissue plasminogen activator (mt-PA) with heparin and aspirin to ensure definite antithrombin and antiplatelet efficacy, followed by back-up percutaneous transluminal coronary angioplasty(PTCA). METHODS: Patients with acute myocardial infarction aged < 80 years who were admitted to our institution within 3 hr of onset of symptoms were immediately treated with oral aspirin 330 mg and intravenous heparin 5,000 IU and were randomized to receive an intravenous bolus of mt-PA (monteplase) 15,000 IU/kg (thrombolytic group, n = 25) or no mt-PA (control group, n = 21), followed by angiography with PTCA if indicated. RESULTS: There were no differences between the two groups in patient characteristics, time from onset to hospital arrival, time to initial angiography, or infarct-related arteries. Significantly more patients had Thrombolysis in Myocardial Infarction flow grade 3 and grade 2/3 at the initial angiography in the thrombolytic group than in the control group (32.0% vs 4.8%, 68.0% vs 14.3%; p = 0.020, p = 0.0003, respectively). PTCA was performed in 88% of the thrombolytic group (stenting employed in 64%) and 95.5% of the control group (stenting in 57%), and the success rate was 95.5% and 100%, respectively. No acute or subacute coronary occlusion was found in either group. Bleeding complications occurred in only one patient in the thrombolytic group, which was bleeding associated with vomiting, and no difference was found in other complications between the two groups. Radionuclide ventriculography using quantitative gated single photon emission computed tomography showed left ventricular end-diastolic volume and left ventricular end-systolic volume tended to be smaller, and the ejection fraction after 3 months of treatment tended to be higher in the thrombolytic group. Myocardial salvage volume was significantly higher in the thrombolytic group. CONCLUSIONS: Hybrid thrombolysis using a low dose of mt-PA with aspirin and heparin promoted significantly early reperfusion. Also, successful reperfusion is achievable at higher rates with back-up PTCA without an increase in complications.

Angioplasty, Balloon, Coronary↗

Case report: endovascular repair of a thoracic aortic aneurysm (saccular type) with a stent-graft.

We describe the repair of a descending thoracic aortic aneurysm (saccular type, maximal size 85 mm) with an endovascular stent-graft in a 69-year-old man with chronic renal failure. The graft consisted of a self-expanding Z-stent covered with a woven polyester graft. An angiogram obtained intraoperatively showed complete thrombosis of the aneurysm. One month after the procedure, a contrast-enhanced computed tomographic (CT) scan showed thrombosis of the aneurysmal sac. A follow-up CT scan obtained 18 months after operation confirmed that the aneurysm had disappeared.

Aged↗

[Translocation of the aortic valve for aortic stenosis in a patient with severe calcification in the aortic root: report of a case].

A 65-year-old woman was admitted to the hospital because of anterior chest pain. Computed tomography and transthoracic 2-D echocardiogram demonstrated aortic valvular stenosis with calcification of whole aortic root. Cardiac catheterization study showed a transaortic pressure gradient of 73 mmHg and coronary angiography showed 75% stenosis at the right coronary ostia. Aortic valve replacement and coronary artery bypass grafting were planned. At operation, sinotubular junction and bilateral coronary ostia severely calcified with stenosis, prompted us to translocate the aortic valve with the composite graft, a 19 mm Bicarbon prosthesis and 25 mm woven Dacron graft. The postoperative course was uneventful. On cardiac catheterization done 27 days after operation, satisfactory valve motion and patent coronary bypass grafts were confirmed.

Aged↗

Touch-free in situ investigation of ancient Egyptian pigments.

Some of the pigments painted on the Funerary Stele of Amenemhat (ca. 2000 B.C.) exhibited at the Egyptian Museum, Cairo and on the walls of the Tomb of Userhat (ca. 1420 B.C.), a rock-cut tomb in Thebes, Egypt, were investigated in situ using both a convenient home-made hand-held type of X-ray diffractometer and a commercial X-ray fluorescence spectrometer in a complementary way under touch-free conditions. CaCO3.3MgCO3 (huntite) was found in the white-painted parts of these two ancient monuments. An arsenic (As)-bearing phase was detected in the yellow-painted parts of the latter monument. The occurrence of huntite in Egypt has not been reported previously.

Egypt, Ancient↗

Angiographic no-reflow phenomenon as a predictor of adverse long-term outcome in patients treated with percutaneous transluminal coronary angioplasty for first acute myocardial infarction.

OBJECTIVES: We sought to elucidate the long-term prognostic importance of angiographic no-reflow phenomenon after percutaneous transluminal coronary angioplasty (PTCA) for acute myocardial infarction (AMI). BACKGROUND: Angiographic no-reflow phenomenon, a reduced coronary antegrade flow (Thrombolysis in Myocardial Infarction [TIMI] flow grade < or =2) without mechanical obstruction after recanalization, predicts poor left ventricular (LV) functional recovery and survival in the early phase of AMI. We hypothesized that angiographic no-reflow phenomenon also predicts long-term clinical outcome. METHODS: We studied 120 consecutive patients with their first AMI treated by PTCA without flow-restricting lesions. The patients were classified as either no-reflow (n = 30) or reflow (TIMI-3) (n = 90) based on post-PTCA cineangiograms to follow up (5.8 +/- 1.2 years) for cardiac death and nonfatal events. RESULTS: Patients with no-reflow had congestive heart failure (p < 0.0001), malignant arrhythmia (p = 0.038), and cardiac death (p = 0.002) more often than did those with reflow. Kaplan-Meier curves showed lower cardiac survival and cardiac event-free survival (p < 0.0001) in patients with no-reflow than in those with reflow. Multivariate analyses disclosed that no-reflow phenomenon was an independent predictor of long-term cardiac death (relative risk [RR] 5.25, 95% confidence interval [CI] 1.85 to 14.9, p = 0.002) and cardiac events (RR 3.71, 95% CI 1.79 to 7.69, p = 0.0004). At follow-up, survivors with no-reflow had higher end-diastolic and end-systolic LV volume indices and plasma brain natriuretic peptide levels, and lower LV ejection fractions (p = 0.0002, p < 0.0001, p = 0.002, p < 0.0001, respectively) than did those with reflow, indicating that no-reflow may be involved in LV remodeling. CONCLUSIONS: Angiographic no-reflow phenomenon strongly predicts long-term cardiac complications after AMI; these complications are possibly associated with LV remodeling.

Adult↗

Immunohistochemistry of chondromodulin-I in the human intervertebral discs with special reference to the degenerative changes.

The expression of the matrix protein chondromodulin-I has been studied in human intervertebral discs of 101 people using immunohistochemical analyses. The purpose of this report is to present data on the metabolic changes that were found to occur in the chondrocytes of intervertebral discs during development and aging. Chondromodulin-I was highly expressed during the gestational period and gradually decreased after maturation. It was detected in both the extracellular matrix and chondrocytes in the zone of hypertrophic cartilage, the zone of proliferative cartilage and the zone of resting cartilage in fetal discs. It was also present in the annulus fibrosus, nucleus pulposus and end-plate cartilage in mature discs. In degenerative discs, chondromodulin-1 immunoreactivity tended to be elevated in the remaining chondrocytes. Our findings suggest that the expression of the protein is developmentally regulated and upregulated through a defense mechanism against the degenerative processes of the aged intervertebral disc.

Adolescent↗

Crystallization of the most active RNA-cleaving deoxyribozyme.

The structural compositions of the most active deoxyribozyme and its derivatives have been examined by electrophoresis, and their crystallization conditions were surveyed for X-ray analysis. It has been found that Mg2+ ion is essential to form the active binary complex between the catalytic DNA and the substrate, and that heat-treatment is effective to prevent formation of the inactive quaternary complex between the two enzymes and the two substrates. Crystals obtained by the hanging drop vapor diffusion method are composed of the active binary complex.

Base Sequence↗

Stent-graft treatment of type B aortic dissection involving the right aortic arch: case report.

A 56-year-old man suffered from type B aortic dissection associated with the right aortic arch and right descending aorta. The patient was successfully treated by implantation of 2 stent-grafts (a 40-mm Z-stent covered with a 37.5-mm woven Dacron graft) and ligation of the dissected left subclavian artery. A postoperative computed tomographic scan revealed thrombosis of the false lumen and a reduction in the descending aortic diameter.

Aortic Dissection↗