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Biomedical subjects

S Asada

Publications and source records attributed to S Asada.

At least 55 records · Page 3Linked to original sources
PubMed1993

Myocardial hibernation in the infarcted region cannot be assessed from the presence of stress-induced ischemia: usefulness of delayed image of exercise thallium-201 scintigraphy.

To examine the relationship between the improvement of wall motion in infarcted regions after percutaneous transluminal coronary angioplasty (PTCA) and thallium-201 uptake in the delayed image of exercise thallium-201 scintigraphy before PTCA, 14 patients with anterior old myocardial infarction were studied. Exercise thallium-201 scintigraphy was performed before PTCA of left anterior descending artery, and mean percent thallium-201 uptake of abnormal segments was calculated in the initial and 4-hour delayed images. Left ventricular angiography was performed during catheterization, before, and 4 to 13 months after PTCA; and regional ejection fraction of anterior wall was calculated. Atrial pacing stress test with the measurement of lactate concentration of aorta and great cardiac vein was performed during catheterization before PTCA. In five patients with mean percent thallium-201 uptake in the delayed image < or = 50% (group I), regional ejection fraction did not increase after PTCA (23% +/- 9% to 24% +/- 12%). In the other nine patients with mean percent thallium-201 uptake > 50% (group II), regional ejection fraction increased significantly after PTCA (39% +/- 18% to 47% +/- 14%; p < 0.05). There was no significant difference in regional ejection fraction, lactate extraction ratio during maximal pacing, and the redistribution of exercise thallium-201 scintigraphy between the two groups before PTCA. Thus the delayed image before PTCA is useful to detect reversible nonfunctioning viable myocardium (hibernating myocardium) in the infarcted region. However, the wall-motion abnormality and the degree of stress-induced ischemia in the infarcted region before PTCA may not be necessarily useful for the detection of hibernating myocardium.

Aged↗
PubMed1993

Late reperfusion for acute myocardial infarction limits the dilatation of left ventricle without the reduction of infarct size.

BACKGROUND: While previous clinical studies have shown a possible beneficial effect of the reperfusion performed at a relatively late phase of acute myocardial infarction ("late reperfusion") in preventing left ventricular enlargement, the mechanism has not been clarified. METHODS AND RESULTS: Of 89 patients with an initial anterior myocardial infarction, reperfusion was successful in 69. These 69 were divided into three groups according to the time required to achieve reperfusion after the onset of symptoms: early-reperfused (< 3 hours from the onset to reperfusion; n = 22), intermediate-reperfused (3 to 6 hours from the onset to reperfusion; n = 28), and late-reperfused (> 6 hours from the onset to reperfusion; n = 19). The 20 patients whose infarct-related artery were occluded in the acute phase as well as 1 month later was classified as nonreperfused. Infarct size, evaluated as defect volume by 201Tl single-photon emission computed tomography 1 month after the onset, was 1593 +/- 652 units (mean +/- SD) in the late-reperfused group, significantly larger (P < .05) than that of the intermediate-reperfused (1066 +/- 546 U) or the early-reperfused groups (372 +/- 453 U) but not different from that of the nonreperfused group (1736 +/- 562 U). Wall motion abnormality index as well as global ejection fraction evaluated by left ventriculography 1 month after the onset showed that late reperfusion did not preserve the left ventricular wall motion and function. These results indicate that the earlier reperfusion decreased the size of the infarction and preserved left ventricular function, whereas late reperfusion (> 6 hours after onset) did not limit infarct size or preserve left ventricular function. In contrast, the end-diastolic volume index did not differ significantly among the early-reperfused (50 +/- 15 mL/m2), intermediate-reperfused (54 +/- 14 mL/m2), and late-reperfused (53 +/- 19 mL/m2) groups; those were significantly smaller than that of the nonreperfused group (68 +/- 12 mL/m2; P < .05). Left ventriculographic data obtained in both the acute and chronic phase in 39 patients showed that left ventricular volumes increased significantly during the course of myocardial infarction only in the nonreperfused group. CONCLUSIONS: Late reperfusion appeared to prevent ventricular dilatation acute myocardial infarction independent of the limitation of infarct size.

Adult↗
PubMed1993

Two different histamine-sensitizing activities of pertussis vaccine observed in mice on the 4th and 12th days of sensitization.

The histamine-sensitizing (HS) activities of commercial precipitated diphtheria-tetanus-purified pertussis combined vaccines (DTP) submitted to the national quality control tests during the period from 1980 to 1991 were measured in mice on days 4 (EHS) and 12 (LHS) of sensitization. Annual averages of the EHS activity of the vaccines showed continuous decline during the period, while the LHS activity stayed unchanged except for 1990 and 1991. Correlation analysis between these two HS activities revealed that the vaccines could be differentiated into two groups, those showing a significant correlation and those lacking it, depending on their source manufacturers. When the vaccine was incubated at 37 C for four weeks, both the HS activities increased for the first couple of weeks at different rates, reaching their peaks after different periods; three weeks for the EHS activity and two weeks for the LHS activity. Treating the reference pertussis vaccine (for toxicity tests) with anti-pertussis toxin horse serum neutralized completely the EHS activity but the LHS activity resisted the serum. These findings suggest a possible difference between the two HS activities in their mode of action, therefore, in their roles in possible reactogenicity of the vaccine, and a necessity for separate controls of the two activities.

Animals↗
PubMed1992

Effects of anti-acid secretory agents on various types of gastric mucus.

Total, acidic, and sulfated mucus contents in the gastric mucosa were evaluated after administration to rats of ranitidine and pirenzepine, antagonists of gastric parietal cell receptors; omeprazole, a proton-pump/inhibitor; and misoprostol, a prostaglandin E1 preparation. Total gastric mucus content was significantly decreased by ranitidine, but contents of acidic mucus and sulfated mucus showed a slight increase. Total mucus and acidic mucus contents were slightly increased after administration of pirenzepine, whereas the sulfated mucus content was significantly increased. The total gastric mucus content was significantly decreased after administration of omeprazole, but acidic mucus increased slightly and sulfated mucus increased significantly. All mucus contents were unchanged after administration of anti-acid secretory dose of midoptodyol. After administration of either ranitidine or omeprazole, the neutral mucus content decreased, but the total acid and sulfated mucus contents were not decreased. Changes in various mucus contents following inhibition of acid secretion are different for different drugs, and it was suggested that production of neutral mucus and secretion of acid mucus were reduced by strong inhibition of acid secretion.

Animals↗
PubMed1992

Synergistic antiproliferative effect of interferons and azidothymidine on HL60 cells.

Proliferation of human leukemia cells, HL60, was synergistically inhibited by a combination of human interferons and azidothymidine in vitro. Combination of interferon-gamma (3000 U/ml) and azidothymidine (30 microM) inhibited cell growth by 76%, whereas interferon-gamma alone suppressed growth by 23% and azidothymidine alone by 33%. Interferon-alpha-2a and interferon-beta also exerted synergistic effects with azidothymidine, but the potentiation was weaker than that by the combination of interferon-gamma and aziodthymidine.

Cell Division↗
PubMed1992

Immunological determination of fecal hemoglobin and transferrin levels: a comparison with other fecal occult blood tests.

Immunological determination of fecal hemoglobin and transferrin levels was performed in inpatients on an unrestricted diet, including patients with colon cancer or polyps and a control group. When hemoglobin levels of 5.1 micrograms/g feces and transferrin levels of 0.4 microgram/g feces were designated as positive, 48 of the 60 fecal specimens from colon cancer patients were positive. This result was significantly superior to that for another fecal occult blood immunological test (FECA-EIA) (p less than 0.005), and similar to the results of two chemical tests (guaiac and Hemoccult). Twenty-eight of the 78 fecal specimens from patients with colonic polyps were positive, again a result superior to the FECA-EIA (p less than 0.005) and similar to the chemical tests. Three of the 99 control fecal specimens were positive, which was a similar result to that obtained with the FECA-EIA and significantly superior to the chemical tests (both p less than 0.005). Thus, combined detection of fecal hemoglobin and transferrin levels can be used as a fecal occult blood test in patients without dietary restriction.

Aged↗
PubMed1991

Oriental orchid (Cymbidium pumilum) attracts drones of the Japanese honeybee (Apis cerana japonica) as pollinators.

The discovery that drones of the Japanese honeybee (Apis cerana japonica) pollinate the oriental orchid (Cymbidium pumilum) is reported. Drones are attracted to the orchid flower aroma mainly during their mating flights in April through May. Some drones cluster on the flower racemes and others insert their heads deep into the flowers. Drones with pollinia on their scutellum visit other orchids, which facilitates pollination. Individual workers and swarming colonies are also strongly attracted by the flower aroma, but the allopatric western honeybee (Apis mellifera) is not attracted.

Animals↗
PubMed1991

Comparative studies of embryotoxic action of ethylenethiourea in rat whole embryo and embryonic cell culture.

The effects of ethylenethiourea (ETU) were investigated using rat (Wistar-imamichi) embryos cultured from days 11 to 13 of gestation or cultured rat embryonic cells extracted on day 11. Malformations in cultured embryos at the concentration of 30 micrograms/ml of ETU were found in the head and tail, which were severely affected, as well as the limb and face. All embryos exposed to 150 and 300 micrograms/ml of ETU had malformed heads, tails, limbs, and facial configurations. Protein contents of the cultured embryos were decreased dose-dependently at the concentrations ranging from 30 to 300 micrograms/ml. In the histological studies of the cultured embryos with ETU, thinner neuroepithelium in head was observed. In the embryonic cells extracted on day 11 of gestation, ETU dose-dependently inhibited the differentiation of midbrain (MB) cells into neurons and that of limb bud (LB) cells into chondrocytes at the concentrations ranging from 30 to 600 micrograms/ml of ETU. The concentrations of ETU that inhibited the production of differentiated foci by 50% (IC50) were 170 micrograms/ml in LB cells of day 11, and greater than 600 micrograms/ml in LB cells on day 12 of development. Therefore, differentiation of MB cells was more sensitive to ETU than the differentiation of LB cells. These results indicated that there was a reasonable correlation of ETU induced changes in cultured whole embryos and embryonic cells.

Abnormalities, Multiple↗
PubMed1991

Serial transcardiac lactate metabolism in post-reperfused stunned myocardium in evolving myocardial infarction.

To elucidate the relationship between lactate metabolism following reperfusion and restoration of left ventricular (LV) function, we assessed serial changes in transcardiac lactate metabolism following reperfusion therapy in 67 patients admitted to hospital within 6 h of the onset of acute anteroseptal myocardial infarction. Left ventriculograms taken about 30 min after reperfusion therapy revealed marked dyskinesis in the anteroapical region in all subjects. According to the regional ejection fraction (rEF), determined 4 weeks later as an index of LV function, patients were divided into 3 group: 1) Restored LV group: 28 patients with reperfusion and restored LV function (rEF greater than 30%); 2) Poor LV group: 26 patients with reperfusion but poor LV function (rEF less than 30%); 3) Failure group: 13 patients with failed reperfusion and occluded left anterior descending coronary artery. Although there was no difference in elapsed time and time to peak creatine phosphokinase (CPK) between the former 2 groups, the Restored LV group demonstrated lower peak CPK values, suggesting that these patients had less myocardial injury. Immediately after reperfusion, both groups showed transcardiac lactate production. In the Restored LV group, aerobic lactate metabolism was restored early after reperfusion (at 6 h), while in the Poor LV group prolonged anaerobic lactate metabolism was observed. These results suggest that an early restoration of aerobic metabolism might be a sign of stunned and viable myocardium, and a sustained lactate production might relate to a sustained process of myocardial injury.

Adult↗
PubMed1991

[Two surgical cases of synchronous double carcinoma of the lung and esophagus and review of 10 documented cases in Japan].

Synchronous double carcinoma of the lung and the esophagus is extremely rare disease. In Japan, 13 cases have reported by Abo and only 10 clinical cases have been documented so far. We describe two cases of synchronous double carcinoma of the lung and the esophagus. Case 1. A 74-year-old man was admitted to our hospital because of the abnormal shadow of the chest X-ray film. Left upper lobectomy was carried out for the lung carcinoma. Because of dysphagia after surgery, upper GI series and endoscopic biopsy were performed, and midesophageal carcinoma was revealed. Radical operation of the esophageal carcinoma was performed 2 months after the first operation. Pathological diagnosis of the lung tumor and the esophageal tumor were well differentiated adenocarcinoma and moderately differentiated squamous cell carcinoma respectively and both of them were early cancer. After 22 months of the second operation, he is doing well. Case 2. a 66-year-old man was operated on because of the esophageal carcinoma in other hospital. Abnormal shadow appeared in his X-ray film 10 months after operation. Although he received chemotherapy as metastatic lung cancer, bronchoscopic examination revealed it adenocarcinoma. We performed segmental lobectomy to him 17 months after the first operation. Pathological diagnosis was large cell carcinoma of the lung. He is also doing well 18 months after the second operation.

Adenocarcinoma↗
PubMed1990

Percutaneous transluminal coronary angioplasty using kissing balloon technique in the left main trunk.

This report describes the feasibility of the kissing balloon technique in the left main trunk in selected patients who had stenosis in the left main trunk involving bifurcation of the anterior descending artery and the circumflex artery and who also had enough blood flow to distal coronary to prevent left ventricular dysfunction during balloon occlusion or abrupt re-closure in the left main.

Aged↗
PubMed1990

Electroporation as a new technique for producing transgenic fish.

A recombinant plasmid, pMV-GH, containing rainbow trout growth hormone cDNA fused to mouse metallothionein I promoter, was introduced into medaka (Oryzias latipes) by electroporation. Of 3109 fertilized eggs treated with electric pulses (750 V/cm, 50 microseconds, 5 times), 783 (25%) hatched out. Four percent of the hatchlings were transgenic. To obtain transgenic lines, 180 hatchlings were maintained and 35 of them grew into adult fish. Two of these fish were transgenic. When one transgenic fish was mated with a normal female, the transgene was found in all the F1 offspring assayed. In F2 offspring obtained by mating transgenic F1 fish, 88% were transgenic.

Animals↗
PubMed1990

Correlation of gastric mucous volume with levels of five prostaglandins after gastric mucosal injuries by NSAIDs.

After administration of NSAIDs (aspirin and indomethacin), chronological changes in gastric mucous volume were determined. These mucous volume changes were evaluated in relation to the development of gastric mucosal injuries. Furthermore, quantitative changes in five kinds of prostaglandins (PGs) in the gastric mucosa were measured after administration of NSAIDs. Gastric mucus volume was measured using a video image processor (VIP), and five kinds of PGs were fractionated by high-performance liquid chromatography (HPLC) and quantitatively determined by radioimmunoassay (RIA). We found that NSAIDs decrease the levels of five kinds of PGs to the same extent. Also, gastric mucous volume is decreased after administration of aspirin and increased after administration of indomethacin. Accordingly, it is possible that each NSAID has a different mechanism of producing the gastric mucosal injury and acts on gastric mucus in a different manner. There was no parallel in changes between gastric mucous volume and PG levels of the different PGs in the gastric mucosa after administration of NSAIDs.

Animals↗
PubMed1990

Reversible pharmacokinetic profiles of canrenoic acid and its biotransformed product. Canrenone in the rat.

Pharmacokinetic profiles of canrenoic acid (CRA) and canrenone (CR), the reversible metabolite of CRA, were studied in the rat after intraportal (pv) administration in comparison with those after intravenous (iv) administration using an interconversion model. In the clearances for the irreversible loss. CL20 of CR was larger than CL10 of CRA. Nevertheless, the real plasma clearance of CR was less than that of CRA. The distribution volume V1 of CRA was almost close to the real distribution volume Vss.real.D of CRA at the steady state. The hepatic available fraction of CRA, FH1 and sequential hepatic available fraction of generated metabolite, FH2, were estimated. Simultaneous computer multi-line fitting of plasma concentration-time data was carried out and the adequacy of pharmacokinetic parameters in this model was tested using the iterative nonlinear least-squares regression program, MULTI.

Animals↗
PubMed1990

Alteration of natural killer cell subsets (two color analysis) and their activity in peripheral blood in inflammatory bowel disease.

The natural killer (NK) activity and NK cell subsets in peripheral blood were evaluated in patients with inflammatory bowel disease (IBD), by using 51Cr release cytotoxicity assay and two color flowcytometry analysis. The peripheral blood NK activity was significantly lower in IBD than that in normal controls. This decrease of the NK activity was independent on the disease activity of IBD but dependent on the steroid medication. The total population of NK cells (Leu 7+ or 11c+ cells) did not change in IBD as compared with those of normal controls. However, the proportions of Leu7+11c- cells and Leu7-11c+ cells in IBD were higher and lower, respectively as compared with those of normal controls. These findings suggest that the maturation step of NK cell lineages might be impaired in IBD. The decrease of NK activity in IBD was supported by the change in the proportion of NK cell subsets described above. It was thought that such a change in NK cell subsets might be a specific finding in IBD patients, because it was not observed in patients with non-IBD colitis.

Adult↗
PubMed1990

[Study on the usefulness of haptoglobin used on endoscopic injection sclerotherapy].

The effect of haptoglobin (Hp) used on endoscopic injection sclerotherapy (EIS) was evaluated by examining the increase of serum free hemoglobin (FHb) and the changes of renal function. In control group, the increase of serum FHb (delta FHb) was paralleled with the volume of 5% ethanolamine Oleate (EO) injected intravariceally, and free Hp (FHp) was disappered in this group soon after EIS. On the contrary, in the group treated with Hp, neither the increase of FHb nor decrease of FHp were recognized. The significant increase of urine beta 2 microglobulin and NAG was recognized in control group. Therefore, if Hp is used at initial EIS, it would be prevented that serum FHb due to intravascular hemolysis increases, consequently the possibility of renal dysfunction.

Adult↗
PubMed1989

Comparative pharmacokinetics of acetohexamide and its metabolite, hydroxyhexamide in laboratory animals.

The pharmacokinetic profiles of the hypoglycemic agent, acetohexamide (AH) and its major active metabolite, hydroxyhexamide (HH) were studied in three species of laboratory animals after intraperitoneal (ipl) administration in comparison with those after intravenous (iv) administration of AH and of the preformed metabolite HH. Reductive biotransformation of AH to HH was reversible in rats and guinea pigs, while it was irreversible in rabbits. The parameters of reversible drug-metabolite pharmacokinetics were calculated, including essential clearances of reversible and irreversible elimination, volumes of distribution at the steady state and sojourn times or turnover rates of the metabolite pair. An interconversion model, which incorporated a first-pass metabolism, was applied to the disposition kinetics of AH and HH, and the available fractions of AH and generated metabolite HH in each species were elucidated.

Acetohexamide↗