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Biomedical subjects

K Yano

Publications and source records attributed to K Yano.

At least 559 records · Page 31Linked to original sources
PubMed1989

Cloning and sequencing of two tandem genes involved in degradation of 2,3-dihydroxybiphenyl to benzoic acid in the polychlorinated biphenyl-degrading soil bacterium Pseudomonas sp. strain KKS102.

Two genes involved in the degradation of biphenyl were isolated from a gene library of a polychlorinated biphenyl-degrading soil bacterium, Pseudomonas sp. strain KKS102, by using a broad-host-range cosmid vector, pKS13. When a 3.2-kilobase (kb) PstI fragment of a 29-kb cosmid DNA insert was subcloned into pUC18 at the PstI site downstream of the lacZ promoter, Escherichia coli cells carrying this recombinant plasmid expressed 2,3-dihydroxybiphenyl dioxygenase activity. Nucleotide sequencing of the 3.2-kb PstI fragment revealed that there were two open reading frames (ORFI [882 base pairs] and ORFII [834 base pairs], in this gene order). Results of analysis of Tn5 insertion mutants and unidirectional deletion mutants suggested that the ORFI coded for 2,3-dihydroxybiphenyl dioxygenase. When the sequence of ORFI was compared with that of bphC of Pseudomonas pseudoalcaligenes KF707 (K. Furukawa, N. Arima, and T. Miyazaki, J. Bacteriol. 169:427-429, 1987), the homology was 68%, with both strains having the same Shine-Dalgarno sequence. The result of gas chromatography-mass spectrometry analysis of the metabolic product suggested that the ORFII had meta cleavage compound hydrolase activity to produce benzoic acid. DNA sequencing suggested that these two genes were contained in one operon.

Amino Acid Sequence↗
PubMed1989

Cloning and sequencing of the gene encoding the 72-kilodalton dehydrogenase subunit of alcohol dehydrogenase from Acetobacter aceti.

A genomic library of Acetobacter aceti DNA was constructed by using a broad-host-range cosmid vector. Complementation of a spontaneous alcohol dehydrogenase-deficient mutant resulted in the isolation of a plasmid designated pAA701. Subcloning and deletion analysis of pAA701 limited the region that complemented the deficiency in alcohol dehydrogenase activity of the mutant. The nucleotide sequence of this region was determined and showed that this region contained the full structural gene for the 72-kilodalton dehydrogenase subunit of the alcohol dehydrogenase enzyme complex. The predicted amino acid sequence of the gene showed homology with sequences of methanol dehydrogenase structural genes of Paracoccus denitrificans and Methylobacterium organophilum.

Acetobacter↗
PubMed1989

Sarcolemmal Ca2+ transport activities in cardiac hypertrophy caused by pressure overload.

To examine Ca2+ transport activities in sarcolemmal membrane in cardiac hypertrophy caused by pressure overload, rats were subjected to aortic banding for 28 days. Heart-to-body weight ratio was increased by 46% in aortic-banded animals in comparison with the sham-operated rats. Ouabain-sensitive Na+-K+-ATPase activity in sarcolemma (SL) from hypertrophied hearts was not different from that in the control preparation. The initial rate of Na+-dependent Ca2+ uptake in SL vesicles from the hypertrophied hearts was stimulated by 53% compared with the control vesicles. ATP-dependent Ca2+ uptake and Ca2+-stimulated adenosinetriphosphatase (ATPase) activities in SL from hypertrophied hearts were increased by 35%. The number of Ca2+ channels estimated by [5-methyl-3H]nitrendipine binding was decreased by 33% in SL from hypertrophied hearts. Total and individual phospholipid contents in the hypertrophied heart preparations were not different from those in the control, except that phosphatidylcholine and phosphatidylethanolamine contents were significantly increased. Sarcolemmal preparations from hypertrophied hearts from the 22-wk-old spontaneously hypertensive rats exhibited changes in Na+-Ca2+ exchange and Ca2+-pump activities (similar to those observed in banded hearts), whereas the Na+-K+-ATPase activity decreased, [3H]nitrendipine binding increased, and phospholipid contents were not different. Thus, although differences were defined between two types of hypertrophy, these results suggest alterations in the sarcolemmal Ca2+ transport activities that may serve as an adaptive mechanism for the removal of Ca2+ from the myocardial cells during the development of cardiac hypertrophy.

Animals↗
PubMed1989

Serum cholesterol and hemorrhagic stroke in the Honolulu Heart Program.

During an average 18 years of follow-up for 7,850 Japanese-American men in Hawaii who were free of stroke at entry, 116 developed hemorrhagic stroke (subarachnoid hemorrhage or intracerebral hemorrhage). There was a significant (p = 0.001) inverse association between serum cholesterol and the risk of intracerebral hemorrhage but not of subarachnoid hemorrhage. This inverse association was nonlinear, with a higher incidence rate only for men with serum cholesterol in the lowest quintile (less than 189 mg/dl). The relative risk (lowest quintile/other four quintiles) was 2.55 (95% confidence interval 1.58-4.12) after controlling for age, blood pressure, serum uric acid, cigarette smoking, and alcohol consumption. There was no evidence for an interaction between blood pressure and serum cholesterol, although the inverse association was stronger for normotensive than for hypertensive men. Public health implications would differ in different countries depending on the relative frequency of intracerebral hemorrhage and on the distribution of serum cholesterol levels in the population.

Aged↗
PubMed1989

Twenty-year trends in mortality from chronic obstructive pulmonary disease: the Honolulu Heart Program.

There is evidence of a rising trend in COPD mortality. Whether this is due to changes in coding or diagnostic practices, increase in disease incidence or severity, or other causes is unknown. The Honolulu Heart Program (HHP) has followed a cohort of 11,136 Japanese-American men, 45 to 65 yr of age at onset, from 1965 to 1984. Following a fixed protocol, study physicians assigned cause of death after review of hospital records, pathology and autopsy reports, the death certificate, and, in doubtful cases, after interview with family and personal physician. The eighth revision of the international Classification of Diseases was used throughout. During 20 yr of follow-up, 2,624 men died, 113 from COPD by HHP coding and 105 from COPD by State Health Department (HD) coding. There was no change in age-adjusted or age-specific COPD mortality rates from 1965 to 1984 by HHP coding (tests for trend, p greater than 0.05). In contrast, when HD coding was used there was a significant decline in COPD mortality over the same time period. The frequency with which COPD was found on the death certificate decreased significantly for diagnoses listed in Section 1 and increased for those in Section 2. Current smokers showed increasing trends and past smokers decreasing trends in COPD mortality. When HHP and HD codings were compared, there was agreement in only 46% (69 of 149) of the cases. Agreement was greater in 1965-1974 than in 1975-1984. This study found no evidence of increasing mortality rates from 1965 to 1984 in this cohort of Japanese-American men.(ABSTRACT TRUNCATED AT 250 WORDS)

Age Factors↗
PubMed1989

Simultaneous monitoring of electrocardiogram and arterial blood pressure during exercise-induced syncope in a patient with severe aortic stenosis--a case report.

A sixty-six-year-old man with severe aortic stenosis, in whom simultaneous and continuous monitoring of the electrocardiogram and arterial blood pressure was performed immediately before, during, and following recovery from exercise-induced syncope, is reported. During exercise the patient developed anginal pain associated with a gradual fall of arterial blood pressure followed by syncope. At the onset of the syncope, arterial blood pressure was extremely low, and the electrocardiogram showed sinus tachycardia. It was assumed from these findings that profound hypotension, induced by peripheral vasodilatation and ischemic myocardial depression leading to inappropriately low cardiac output, was the underlying factor mainly responsible for the occurrence of exercise-induced syncope in the present case.

Aged↗
PubMed1989

Effects of chronic hypokalemia on ventricular vulnerability during acute myocardial ischemia in the dog.

Chronic hypokalemia (2.9 +/- 0.2 mEq/L) was induced in 10 dogs by a low potassium diet and furosemide administration. Five control dogs with normokalemia (5.0 +/- 0.3 mEq/L) were fed an ordinary diet. Three of the 10 hypokalemic dogs had electrically induced, nonsustained ventricular tachycardia (NSVT) and ventricular fibrillation (VF); none of the 5 control dogs had these ventricular arrhythmias. After ligation of the left anterior descending coronary artery (LAD), 4 of the 10 hypokalemic dogs developed spontaneous VF and 6 had electrically induced NSVT and VF, whereas 2 of the 5 control dogs had only NSVT. The effective refractory period (ERP) of the ventricles of the hypokalemic dogs was slightly longer than that of the control dogs. After LAD ligation, only the ERP of the anterior wall of the left ventricle was prolonged significantly in either group (p less than 0.01). The ventricular fibrillation threshold (VFT) of hypokalemic dogs was significantly lower than the control dogs (p less than 0.05), and was reduced markedly (p less than 0.05) after LAD ligation. A positive correlation between VFT and serum potassium level was observed. Thus, chronic hypokalemia increases ventricular vulnerability. This effect depends upon the severity of hypokalemia and is markedly augmented by acute myocardial ischemia. These findings indicate that, in clinical settings, preexisting hypokalemia and its severity may play important roles in the occurrence of lethal ventricular arrhythmias during the acute phase of myocardial infarction.

Acute Disease↗
PubMed1989

Potentiation by Bay-K-8644 of the adrenal catecholamine secretory response to Ca re-introduction and ouabain: possible activation of Ca influx linked with Na efflux.

Catecholamine (CA) secretion induced by Ca re-introduction or ouabain in the presence of Ca is markedly potentiated by Bay-K-8644 in the perfused cat adrenal. The mechanism of potentiation by this Ca agonist was investigated using perfused cat adrenal and isolated bovine chromaffin cells. The stimulatory effect of Bay-K-8644 on the response to Ca was very slight when cat adrenal was perfused with a Ca-deficient medium, in which 1 mM Mg was added or the concentration of Na was lowered. The inhibitory effect of Mg was reversed by inhibition of the Na pump with K deprivation, ouabain, or KCN. The secretion induced by ouabain during maintained depolarization at a lowered concentration (0.25 mM) of Ca, which is supposed to be due to Ca influx in exchange for Na efflux, was larger in the Bay-K-8644 treated adrenal than that in the untreated adrenal. The increase in secretion by the delayed addition of Bay-K-8644 during perfusion with a high K medium containing ouabain was larger when the concentration of Na in a high K medium was higher. When isolated chromaffin cells were stimulated with a Na-free (Tris) medium containing 0.5 mM Ca, CA secretion from and 45Ca uptake into the cells preincubated with a divalent cation-free medium were potentiated by Bay-K-8644. The stimulatory effect of Bay-K-8644 was not seen when a Ca-free treatment medium contained Mg or lacked Na, but the inhibitory effect of Mg was reversed by the addition of ouabain or KCN to the pretreatment medium. When isolated cells preloaded with 45Ca were superfused with a Ca-free medium, Ca re-introduction increased the rate of Ca efflux only under conditions in which significant increases in CA secretion and 45Ca uptake were previously observed under the static incubation system. Bay-K-8644 further increased this Ca efflux rate under these conditions. These results support the view that Ca influx linked with Na efflux is through a pathway with properties similar to those of voltage-dependent Ca channels, and suggest that this Ca pathway is activated by Bay-K-8644, which is an activator of voltage-dependent Ca channels.

3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethy↗
PubMed1989

[Usefulness of measurement of hepatic arterial blood flow during surgery to insert an arterial reservoir in unresectable hepatocellular carcinoma].

In a case of hepatocellular carcinoma, complicated with celiac arterial constriction, for which resection was impossible, we measured the blood flow in the hepatic artery using an ultrasonic, transit-time rheometer during surgery, and consequently inserted a reservoir safely. The measurement of the blood flow in this case demonstrated that the proper hepatic artery was provided with blood from superior mesenteric artery by the gastroduodenal artery and that the blood flow of the common hepatic artery was directed to the root part of the celiac artery. Moreover, because blood flow through the proper hepatic artery was greater while clamping the common hepatic artery than the gastroduodenal artery, cannulation was carried out from the common hepatic artery. Postoperatively, when recombinant interleukin-2(rIL-2) was infused from the reservoir, the tumor disappeared on imaging pictures, and the level of AFP (which was high preoperatively) was reduced, which was thus judged as a complete response. These results indicated the usefulness of measurement of blood flow in surgery of inserting a reservoir in cases with abnormal blood circulatory dynamics.

Carcinoma, Hepatocellular↗
PubMed1989

Myeloperoxidase gene expression in acute leukemias.

Since myeloperoxidase (MPO) is considered to be a critical marker of differentiating acute myelogenous leukemia (AML) from acute lymphocytic leukemia (ALL), the analysis of MPO gene expression may provide further insight into the leukemia classification and the lineage fidelity of leukemia cells. By Northern blot hybridization using full-length MPO cDNA as a probe, approximately 66% of AML cells (3/4 M1 cases, 2/4 M2 cases, 15/15 M3 cases, 11/15 M4 cases, and 2/12 M5 cases) were found to express MPO mRNAs, whereas none of 18 ALL cases did. MPO mRNA was detectable when AML cells contained at least 10% peroxidase-positive cells. APL (M3) cells expressed high levels of mRNA in accordance with heavy staining for peroxidase.

Gene Expression↗
PubMed1989

[Indications for PTCA for the infarcted myocardium without redistribution by T1-201 myocardial scintigraphy: the role of two-dimensional echocardiography].

Persistent myocardial hypoperfusion in delayed images demonstrated by preoperative exercise T1-201 myocardial scintigraphy may improve after PTCA. The purpose of this study was to test whether PTCA-induced improvement could be anticipated by means of preoperative two-dimensional echocardiography and exercise T1-201 myocardial scintigraphy. The subjects consisted of 24 patients with prior myocardial infarction, in whom serial exercise T1-201 myocardial scintigraphy had been performed during treadmill exercise testing. The patients were divided into three groups according to the results of two-dimensional echocardiography (Group I: eight patients with hypokinesis in the infarct zone; Group II: eight patients with akinesis without a thin wall in the infarct zone; Group III: eight patients with akinesis with a thin wall in the infarct zone). Results were as follows: 1. There was no significant difference in initial T1-uptake in all the 24 patients before and after PTCA, though significantly increased uptakes were observed in Groups I and II after PTCA. 2. There were significant differences in preoperative initial T1-uptakes among the three groups. 3. In Group II, the patients with postoperative scintigraphic improvement had significantly higher preoperative initial T1-uptakes. 4. The postoperative improvement of myocardial perfusion was accompanied by improvement in wall motion. Therefore, an infarct zone without delayed redistribution in T1-201 myocardial scintigraphy does not necessarily indicate scar tissue. However, it may represent hypokinetic or akinetic areas without thin walls on two-dimensional echocardiograms, suggesting a hibernating myocardial state due to chronic intermittent episodes of myocardial ischemia. In such cases, improvement of myocardial perfusion after PTCA can be expected.

Adult↗
PubMed1989

[Ultrasonography-guided cobalt-60 brachytherapy of malignant glioma].

Brachytherapy with cobalt-60 source is reported. In this method it is characterized that the source is inserted interstitially with remote control system by after-loading method via outer catheter (using tandem tube), which was established in the center of residual tumor, using ultrasonography guide with trepanation, or intraoperatively put within the dead space after tumor resection. Six cases of deep-seated and recurrent malignant glioma, were treated with this method. A total dose of 20 to 45 Gy (10 to 15 Gy/day for 2 to 3 days) was delivered to the target. Additionally conventional external irradiation was followed. The effect of cobalt-60 brachytherapy on such tumors were favorable especially for well-circumscribed glioma less than 3 cm on CT scan.

Adolescent↗
PubMed1989

Intratumoural injection of calcium channel blocker enhances cytotoxicity of adriamycin in Ehrlich ascites solid tumour.

We found that the concentration of adriamycin (ADM) within the tumours were nicardipine hydrochloride (Nic) dose-dependent reaching a maximum at a Nic dose of 33.3 mg/kg body weight when Nic was injected intratumourally. In a time-course study, the maximum level of ADM after intratumoural injection of Nic was 1.3-fold higher than the maximum level with both intraperitoneal (ip) injection of Nic and ADM, but occurred later, i.e. 5 h vs 2 h respectively following exposure. Intratumoural injection of Nic prolonged the retention of ADM within the tumour, resulting in concentration levels greater than 0.5 micrograms/g of tumour, 5 to 9 h after exposure. Intraperitoneal injection of Nic and ADM and ip ADM alone resulted in peak intratumoural levels after 2 h that quickly fell after the third hour of exposure to below 0.3 micrograms/g of tumour. Furthermore, in experiments aimed at investigating the therapeutic efficacy of ADM with intratumoural vs ip injection of Nic, we found a 2.8-fold increase in the tumouricidal activity of ADM, when Nic was concurrently injected within the tumour than when it was given intraperitoneally. We conclude that intratumoural injection of Nic enhanced not only acquisition and retention of ADM by Ehrlich ascites tumour tissue, but also strengthened its tumouricidal potency.

Animals↗
PubMed1989

The incidence and prognosis of unrecognized myocardial infarction in the Honolulu, Hawaii, Heart Program.

The incidence of clinically unrecognized myocardial infarctions among 7331 Japanese-American men in Hawaii, aged 45 to 68 years and free of coronary heart disease at entry, was studied on the basis of electrocardiographic changes between successive examinations during 6 years of follow-up. The proportion of asymptomatic myocardial infarction accounted for 33% of transmural (Q-wave) myocardial infarctions identified by temporal changes on electrocardiogram and 22% of all nonfatal infarctions ascertained by either repeated examinations or hospital surveillance. The 10-year prognosis of unrecognized infarction, in terms of mortality from all causes, cardiovascular disease, and coronary heart disease, was worse (with risk ratios of 1.5 to 1.7) than that of recognized infarction, even after adjusting for age and other possible determinants, although the differences were not statistically significant. These findings suggest that regular health check-ups with an electrocardiogram would be important to detect asymptomatic myocardial infarction and to increase the opportunity of taking secondary preventive measures. However, the conclusion should await further studies based on intervention trials to determine the comparative effects of the secondary prevention on the prognosis of clinically recognized vs unrecognized infarction.

Aged↗
PubMed1989

[Quantification of severity and redistribution of ischemic and infarcted myocardium by Thallium-201 polar map: evaluation in patients with single vessel disease].

Quantitative analysis of the polar map obtained from T1-201 single photon emission computed tomogram was employed to assess regional myocardial viability in 66 patients with single vessel coronary artery disease and 16 control subjects. Counts of region of interest in the stenotic and infarcted lesions and normal reference areas were calculated on the polar map. Severity of hypoperfused myocardium was determined as initial percent uptake (%Ui) and delayed percent uptake (%Ud). Redistribution was analyzed as a ratio of %Ud to %Ui (%Ud/%Ui). In the control group, the average %Ui was 85.8 +/- 9.4 and %Ud/%Ui was 1.03 +/- 0.04. Twenty five with reversible defect showed reduced %Ui (51.5 +/- 13.3) and increased %Ud/%Ui (1.37 +/- 0.26). Forty one cases with non-reversible defect were divided into two groups according to the value of %Ui. In the first group with a high %Ui (n = 17), the average %Ui was 74.5 +/- 4.7 and %Ud/Ui was in normal range (1.06 +/- 0.06). In the second group (n = 24), %Ui was most reduced (31.7 +/- 8.7), although %Ud/%Ui was in normal range (1.05 +/- 0.17). No significant correlation was shown between %Ui and %Ud/%Ui in the two groups with non-reversible defect. Correlation between %Ui and %Ud/%Ui was high (r = -0.76) in the group of reversible defect and the group of non-reversible defect with minimal reduced %Ui. It is concluded that the quantitative criteria obtained from polar map is valid to assess regional myocardial viability. The quantitative imaging data were also compared with coronary angiographic and left ventriculographic data.

Aged↗
PubMed1989

Correction of congenital microtia using the tissue expander.

We attempted auricular reconstruction using Radovan-type inflatable silicone expanders in six children and one adult, with the complete hypoplastic, the conchal remnant, and constricted type of microtia. Ear frameworks, including the helix, anthelix, concha, and tragus, were prepared using autologous rib cartilage. Based on the surface area of the normal adult auricle, the silicone expander was tentatively shaped and sized into a rotated semiellipse and expanded with 70 cc saline. Auricular reconstruction on the framework was completed at the time of insertion in four of the seven patients, requiring no elevation of the ear. The reconstructed auricle was satisfactory in both color and texture and had nearly normal sensation. Mild complications were noted in three of the seven patients. However, no resorption of the inserted rib cartilage has been observed 14 months to 2 years and 5 months after the operation. Slight shrinkage of the expanded skin was noted in each patient.

Adolescent↗