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Biomedical subjects

I Kubo

Publications and source records attributed to I Kubo.

At least 19 recordsLinked to original sources

Long-term angiographic prognosis of lesions dilated by coronary angioplasty.

BACKGROUND: To examine the long-term outcome of coronary angioplasty, lesions that remained patent after 3 to 12 months were monitored angiographically at 3-year intervals. There were 252 lesions successfully dilated (from 83% +/- 13% preprocedural stenosis to 19% +/- 14% residual stenosis) between 1983 and 1986 that remained patent on follow-up angiography (23% +/- 15% stenosis) and were monitored further at our outpatient department. METHODS AND RESULTS: Repeat angiography was done for 186 lesions at 2 to 4 years and showed that 179 were patent (0% to 50% stenosis), one had mild stenosis (55% to 70% stenosis), and six had severe stenosis (75% to 100% stenosis). Angiography was repeated for 138 lesions at 5 to 7 years, showing that 127 were patent, four had mild stenosis, and seven had severe stenosis. Finally, angiography was performed for 78 lesions at 8 to 10 years, showing that 63 were patent, four had mild stenosis, and 11 had severe stenosis. CONCLUSIONS: Although numerous lesions were lost to follow-up, most appeared to remain patent for 4 years, after which a significant number developed restenosis.

Angioplasty, Balloon, Coronary

Magnum Meier wires with Crag Fx wire catheter for total occlusive coronary arteries.

Magnum Meier wire was used with Crag Fx wire catheter instead of Magnum balloon catheter to facilitate wire crossing through total occlusion by improving flexibility of the system without losing wire pushability. Of 372 coronary angioplasty procedures performed between January 1994 and April 1995, there were 12 subacute occlusions with an interval of 3 wk or less and 30 chronic occlusions with an interval of > 3 wk. Regular over-the-wire-type balloon catheters failed to dilate four subacute occlusions and nine chronic total occlusions. Magnum Meier wire with Crag Fx wire catheter was tried for one subacute occlusion and four chronic occlusions that were undilatable with a regular balloon system and successfully dilated the subacute occlusion and three of the chronic occlusions. The lesions successfully dilated by this new approach were either long or tandem lesions in vessels that were excessively tortuous or showed an acute angle at the orifice. Thus the Magnum Meier wire with Crag Fx wire catheter can be a useful tool for dilating totally occluded lesions in tortuous coronary arteries.

Angioplasty, Balloon

A chemiluminescent FIA biosensor for phosphate ion monitoring using pyruvate oxidase.

We have constructed an automatic phosphate ion sensing system for the quality control of drinking water. The analyte was detected using the phosphate ion-dependent pyruvate oxidase reaction and the hydrogen peroxide produced was detected by luminol chemiluminescence catalyzed by Arthromyces ramosus peroxidase. We obtained a detection limit of 0.16 microM phosphate ion (5 ppb phosphorus) and it was possible to detect 0.32 microM phosphate ion for 48 days using pyruvate oxidase immobilized on Chitopearl BCW-2601 beads. An excellent correlation (r2 = 1.00) was obtained between the results obtained using our phosphate ion sensor and those using a modified Molybdenum Blue method.

Automation

Antioxidative constituents in Heterotheca inuloides.

Sesquiterpenoids, 7-hydroxy-3,4-dihydrocadalin and 7-hydroxycadalin, and flavonoids, quercetin, kaempferol and their glycosides, isolated from Heterotheca inuloides (Asteraceae), a Mexican medicinal plant known as "arnica", were evaluated as antioxidants. These compounds showed potent scavenging activity on diphenyl-p-picrylhydrazyl (DPPH) radical. Microsomal lipid peroxidation induced by Fe(III)-ADP/NADPH was inhibited by both terpenoids and flavonoids, though only flavonoids possessed superoxide anion scavenging activity in microsome. Flavonoids also scavenged enzymatically and non-enzymatically generated superoxide anion. On the other hand, mitochondrial lipid peroxidation induced by Fe(III)-ADP/NADH was inhibited only by sesquiterpenoids. Furthermore, these terpenes protected mitochondrial enzyme activity against oxidative stress. These results showed that two types of antioxidants existed in the dried flower of H. inuloides and would contribute to protection of tissues against various oxidative stresses.

Animals

Antioxidative action of diterpenoids from Podocarpus nagi.

Diterpenoids, totarol (1), totaradiol (2), 19-hydroxytotarol (3), totaral (4), 4 beta-carboxy-19-nortotarol (5), sugiol (6), isolated from Podocarpus nagi, were evaluated as antioxidants. Microsomal lipid peroxidation induced by Fe(III)-ADP/NADPH and mitochondrial lipid peroxidation induced by Fe(III)-ADP/ NADH were inhibited by these terpenoids. They inhibited linoleic acid autoxidation but not generation of superoxide anion. Totarol (1) protected mitochondrial respiratory enzyme activities against NADPH induced oxidative injury. Totarane diterpenes from P. nagi were shown to be effective to protect biological systems and function against various oxidative stresses.

Abietanes

Hypertrophic cardiomyopathy complicated with acute myocardial infarction due to coronary embolism.

We report a case of acute myocardial infarction due to coronary embolism in a patient with echocardiographically documented hypertrophic cardiomyopathy. Emergency coronary arteriography revealed embolic occlusion of the proximal left circumflex coronary artery and the first diagonal branch. Intracoronary thrombolysis with urokinase and subsequent balloon angioplasty was successful. Transesophageal echocardiography revealed thrombus in the left atrial appendage. Coronary arteriography performed on the 46th hospital day revealed a patent left circumflex coronary artery and diagonal branch. The patient was discharged uneventfully.

Aged

Inhibition of lipid peroxidation by diterpenoid from Podocarpus nagi.

A diterpenoid, totarol (1), from Podocarpus nagi was evaluated as an antioxidant. This diterpenoid inhibited autoxidation of linoleic acid. Mitochondrial and microsomal lipid peroxidation induced by Fe(III)-ADP/NADH or Fe(III)-ADP/NADPH were also inhibited. Nagilactone E (2), a norditerpene lactone isolated from the same source, had no antioxidative activity. Furthermore, totarol protected red cells against oxidative hemolysis. This diterpene was shown to be effective in protecting biological systems against oxidative stresses.

Abietanes

Inhibition of aldose reductase by maesanin and related p-benzoquinone derivatives and effects on other enzymes.

A naturally occurring p-benzoquinone derivative, maesanin, inhibited porcine lens aldose reductase. Systematic investigation of related p-benzoquinone derivatives revealed that 2,5-dihydroxy-p-benzoquinone was a potent inhibitor of aldose reductase and aldehyde reductase but had no effect on NADH oxidase. Kinetic analysis showed this p-benzoquinone exhibited uncompetitive inhibition against DL-glyceraldehyde and noncompetitive inhibition against NADPH.

Aldehyde Reductase

Mode of antibacterial action of totarol, a diterpene from Podocarpus nagi.

The antimicrobial mechanism of totarol was studied using Pseudomonas aeruginosa IFO 3080. This diterpene inhibited oxygen consumption and respiratory-driven proton translocation in whole cells, and oxidation of NADH in membrane preparation. NADH-cytochrome c reductase was inhibited by totarol while cytochrome c oxidase was not. NADH-DPIP reductase and NADH-CoQ reductase were also inhibited. The site of respiratory inhibition of totarol was thought to be near CoQ in the bacterial electron transport chain.

Abietanes

Cytotoxic and antioxidative sesquiterpenoids from Heterotheca inuloides.

Four sesquiterpenoids, beta-caryophyllene, beta-caryophyllene 4,5 alpha-oxide, 7-hydroxy-3,4-dihydrocadalin, and 7-hydroxycadalin, isolated from the dried flower of Heterotheca inuloides Cass. (Asteraceae), have been found to exhibit cytotoxic activity against several solid tumor cell lines. Among them, 7-hydroxy-3,4-dihydrocadalin and 7-hydroxycadalin have also been found to inhibit autoxidative and microsomal lipid peroxidation.

Animals

Antibacterial activity of anacardic acid and totarol, alone and in combination with methicillin, against methicillin-resistant Staphylococcus aureus.

The inhibitory and bactericidal activities of anacardic acid and totarol, alone and in combination with methicillin, were investigated against methicillin-resistant Staphylococcus aureus (MRSA). The growth of two MRSA strains was inhibited by 6 x 25 microg ml-1 of anacardic acid and 0 x 78 microg ml-1 of totarol. The time-kill curve study showed that these two compounds were bactericidal against MRSA. Anacardic acid killed MRSA cells more rapidly than totarol, and no viable cells were detected after being exposed to 6 x 25 microg ml-1 of anacardic acid for 6 h. Anacardic acid showed bactericidal activity against MRSA at any stage of growth, and also even when cell division was inhibited by chloramphenicol. In the combination studies, the minimal inhibitory concentration (MIC) of methicillin was lowered from 800 to 1 x 56 microg ml-1 for MRSA ATCC 33591, and from 800 to 6 x 25 microg ml-1 for MRSA ATCC 33592, by combining with 1/2 x MIC of anacardic acid. The time-kill curves demonstrated synergistic bactericidal activities for these combinations.

Abietanes

Inhibition of lipid peroxidation by sesquiterpenoid in Heterotheca inuloides.

A sesquiterpenoid, 7-hydroxy-3,4-dihydrocadalin, isolated from a Mexican medicinal plant Heterotheca inuloides was evaluated as an antioxidant. This sesquiterpenoid inhibited mitochondrial and microsomal lipid peroxidation induced by Fe(III)-ADP/NADH or Fe(III)-ADP/NADPH. Furthermore, 7-hydroxy-3,4-dihydrocadalin protected red cells against oxidative haemolysis. This sesquiterpene was thus shown to be effective in protecting biological systems against oxidative stresses.

Animals

Indole and (E)-2-hexenal, phytochemical potentiators of polymyxins against Pseudomonas aeruginosa and Escherichia coli.

Combinations of polymyxins and phytochemicals were tested for antimicrobial activity against two gram-negative bacteria. Various degrees of potentiation were found against Pseudomonas aeruginosa and Escherichia coli with (E)-2-hexenal and indole. Three-compound combinations were found to further increase the activity of polymyxin B sulfate and colistin methanesulfonate against both bacteria. Combinations with colistin against P. aeruginosa resulted in the highest degree of potentiation, with a 512-fold increase in colistin antimicrobial activity. These results indicate the potential efficacy of phytochemical combinations with antibiotics to enhance total biological activity.

Anti-Bacterial Agents

Long-term angiographic follow-up of lesions patent 6 months after percutaneous coronary angioplasty.

To determine long-term angiographic prognosis after successful angioplasty (< 50% residual stenosis, > or = 20% reduction of stenosis, and no major complications), coronary angiography was performed 2 to 4 years after angioplasty in patients who were < or = 70 years old at the time of treatment and who showed patency (< or = 50% stenosis) 6 months after the initial procedure. Among 407 lesions that were dilated in 333 patients between 1983 and 1989, 298 (73.2%) lesions were reviewed by long-term angiography after 177 +/- 34 weeks. At long-term follow-up, 4 (1.3%) lesions were totally occluded, 3 (1.0%) had severe stenosis (> or = 75% stenosis), 9 (3.0%) had mild stenosis (> 50% to < 75% stenosis), and 282 (94.6%) were patent (< or = 50% stenosis). The percentage of stenosis of patent lesions decreased from 24% +/- 14% at 6 months to 21% +/- 13% at long-term follow-up (p < 0.0001). No specific clinical or angiographic characteristics were identified in patients with severe stenosis at long-term follow-up. These findings indicate that when patency is obtained 6 months after angioplasty, a 95% long-term patency rate with regression of stenosis can be expected.

Adult

Structural functions of antimicrobial long-chain alcohols and phenols.

Antimicrobial activity of a series of long-chain alcohols and common naturally occurring alcohols were tested against 15 selected microorganisms in order to gain new insights into their structural functions. The maximum activity seems to depend on the hydrophobic chain length from the hydrophilic hydroxyl group, and also the microorganisms being tested. The results obtained with the alcohols exhibit a generally applicable rule to many other compounds.

Alcohols