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Biomedical subjects

M Tahara

Publications and source records attributed to M Tahara.

At least 91 records · Page 5Linked to original sources
PubMed1991

[Non-invasive evaluation of coronary reperfusion using myoglobin: significance of quantitative and semi-quantitative latex agglutination methods].

We assessed the usefulness of myoglobin measured by latex agglutination methods as a parameter for successful reperfusion of the infarct-related artery. Plasma myoglobin levels were measured for 25 patients with acute myocardial infarction in whom thrombolysis and/or percutaneous transluminal coronary angioplasty (PTCA) were performed within 8 hours after the onset of symptoms. Blood samples were obtained before and 56 +/- 26 min (mean +/- SD) after commencing treatment. Plasma myoglobin levels were measured by quantitative and semi-quantitative latex agglutination methods, which required a procedure time of about 10 min. Coronary reperfusion was achieved by thrombolysis or PTCA in 22 cases (Group 1) but was not achieved by thrombolysis in 7 cases (Group 2). Before treatment (4.2 +/- 1.2 hours after the onset of symptoms), plasma myoglobin levels measured quantitatively and semi-quantitatively were 434 +/- 330 ng/ml and 4.6 +/- 4.2 fold, respectively. After treatment, the increased rate of myoglobin was significantly higher in Group 1 (8.4 +/- 7.5 and 9.2 +/- 7.1) than in Group 2 (1.8 +/- 0.5 and 1.7 +/- 0.5). Plasma myoglobin levels measured by quantitative and semi-quantitative latex agglutination methods showed a close correlation (r = 0.91, p < 0.01). In conclusion, measurement of plasma myoglobin levels by latex agglutination methods is a rapid and reliable way to confirm successful coronary reperfusion.

Aged↗
PubMed1991

[Surgical treatment of coexistent aortic, peripheral vascular and coronary disease].

To determine the priority of the surgical treatment of coexistent aortic and coronary disease (CAD), we reviewed 19 cases of aortic aneurysm combined with severe coronary lesions who underwent operation from Jan, 1984 to Aug, 1989. There were 15 cases of abdominal and 4 cases of thoracic aneurysm. All patients had graft replacement for the aneurysm and 12 patients had elective aortocoronary bypass surgery (CABG), one had percutaneous transluminal coronary angioplasty and 6 received medical treatment for CAD. In 6 cases, CABG preceded abdominal aneurysm operation. In 3 cases of ascending thoracic aneurysm, simultaneous coronary and aortic operation were performed. There were no early and late operative death. In an attempt to reduce perioperative myocardial infarction which is one of the most frequent complications of aneurysmal operation, we performed routine coronary angiogram before operation. In 104 patients considered for elective aortic and peripheral vascular disease, coronary angiogram were performed. The incidence of coexistent coronary artery disease in peripheral vascular and aortic disease were 46.1%. The incidence of multiple vessel CAD in patients with aortic and peripheral disease were high. Our surgical strategy for coexistent aortic, peripheral vascular and coronary disease is basically staged operation and simultaneous operation are performed only in ascending and proximal arch aneurysm.

Aged↗
PubMed1991

[The effects of coronary revascularization in patients with severe left ventricular dysfunction].

To evaluate the operative risk of coronary diseased patients who had severe left ventricular dysfunction, we retrospectively reviewed the cases of 798 patients who had received A-C bypass surgery at Juntendo University between Jan. 1984 and Dec. 1989. The patients with severe left ventricular dysfunction (Ejection Fraction less than 30%) (Group-A, n = 9) were compared with the patients with moderately impaired left ventricular function (E.F. 30%-40%) (Group-B, n = 28) and normal left ventricular function (E.F. greater than or equal to 50%) (Group C, n = 34). The mean E.F. were 21.56 +/- 3.72% in Group-A, 34.28 +/- 3.17% in Group-B, 64.19 +/- 12.02% in Group-C. There were no differences between the 3 groups with regard to Cardiac Index, LVEDP, number of diseased vessels, number of grafts, aortic cross clamp time and cardio-pulmonary bypass time. The percentages of patient who needed catecholamines support in postoperatively were 77.8% in Group-A, 46.4% in Group-B and 61.8% in Group-C. There were no operative and hospital deaths in each of the 3 Groups, whereas 2 patients of Group-A died later of noncardiac disease. We propose that patients with severe left ventricular dysfunction (15 less than or equal to EF, less than 30%) benefit from CABG surgery with low risk, and that each left ventricular E.F., Cardiac Index or LVEDP alone were less significant predictors of operative results as measured by preoperative left ventricular function.

Adult↗
PubMed1991

[Pectoralis major muscle flaps for closure of the infected median sternotomy wound].

A case of post-sternotomy mediastinitis due to methicillin-resistant Staphylococcus aureus after aortocoronary bypass procedure was treated with debridement, open clean packing, and delayed wound closure by the technique of pectoral muscle flap mobilization. The cosmetic and functional results were excellent. This technique seems to be a very effective method of treatment for the serious complication of deep sternal infection with mediastinitis after cardiac operation.

Aged↗
PubMed1990

Resorthiomycin, a novel antitumor antibiotic. I. Taxonomy, isolation and biological activity.

Resorthiomycin, a novel antitumor antibiotic, was isolated from the fermentation broth of a strain of Streptomyces collinus by ethyl acetate extraction, silica gel chromatography and HPLC. Resorthiomycin exhibited an in vitro cytotoxic activity against mouse leukemia L5178Y cells (IC50, 15.5 micrograms/ml) and also inhibited the clonogenic activity of a multidrug-resistant mutant of human hepatoma PLC/PRF/5 cells to a greater extent than that of the parental cells. On the other hand, this antibiotic does not possess any antibacterial or antifungal activity.

Animals↗
PubMed1990

Resorthiomycin, a novel antitumor antibiotic. III. Potentiation of antitumor drugs and its mechanism of action.

Resorthiomycin suppressed the clonogenic activity of a multidrug-resistant mutant cell line of Chinese hamster V79 cells more potently than its parental cells. Moreover, resorthiomycin at 40 micrograms/ml potentiated the cytotoxic activity of vincristine and actinomycin D on V79 cells over 3-fold. Uptake of [3H]actinomycin D into V79 cells was stimulated 2-fold by 40 micrograms/ml of resorthiomycin during 2 hours incubation. On the other hand, incorporation of [3H]thymidine and [3H]uridine into mouse leukemia L5178Y cells was inhibited in a dose-dependent manner at resorthiomycin concentrations ranging from 5 to 40 micrograms/ml. In ATP-depleted L5178Y cells, membrane transport of [3H]thymidine and 2-[3H]deoxyglucose was strongly suppressed by resorthiomycin. These results suggest that resorthiomycin acts on the plasma membrane and perturbes some membrane function.

Animals↗
PubMed1990

[Platelet activation during thrombolysis and percutaneous transluminal coronary angioplasty in the acute phase of myocardial infarction].

To clarify the mechanism of recanalization and reocclusion in thrombolysis and percutaneous transluminal coronary angioplasty (PTCA), the plasma concentrations of beta-thromboglobulin (beta-TG), thromboxane B2 (TXB2) and platelet aggregation adenosine diphosphate (ADP) (2 microM/ml, collagen 2 micrograms/ml) were assessed in 11 normal subjects and in 19 patients with acute myocardial infarction whose infarct-related vessels were recanalized by thrombolysis and/or PTCA. In patients with acute myocardial infarction, the plasma concentrations of beta-TG and TXB2 were significantly higher than those in normal subjects (beta-TG: 128 +/- 132 ng/ml vs 38 +/- 17 ng/ml, TXB2: 131 +/- 154 pg/ml vs 36 +/- 18 pg/ml). Collagen-induced platelet aggregation decreased significantly in patients with acute myocardial infarction; whereas, ADP-induced platelet aggregation showed no significant difference. Infarct-related vessels recanalized by thrombolysis (seven patients: group 1) and PTCA (seven patients: group 2) were patent on the follow-up angiograms. Infarct-related vessels were reoccluded in five patients immediately after PTCA or during the follow-up angiography (group 3). Beta-TG and TXB2 did not change before and after recanalization in groups 1 and 2, but increased significantly after recanalization in group 3 (beta-TG: 155 +/- 185 ng/ml----269 +/- 233 ng/ml, TXB2: 104 +/- 87 pg/ml----169 +/- 91 pg/ml). Platelet aggregation did not differ significantly among the three groups. We concluded that platelets are not activated during thrombolysis and/or PTCA in cases without reocclusion, while platelets are markedly activated during PTCA in cases with reocclusion. Thus, it is suggested that platelet activation plays an important role in the mechanism of reocclusion.

Adenosine Diphosphate↗
PubMed1989

Decrease in neonatal suckled milk volume in diabetic women.

To clarify the influence of diseases with hormonal disturbance on puerperal lactation, we studied the amounts of milk obtained by suckling and manual extraction during the first 6 days after delivery and the rate of breast-feeding in 40 patients with diabetes mellitus, 40 with hyperthyroidism, 28 with hypothyroidism and 57 with ovulatory disturbance, and in 40 healthy women. The mean body weight of the patients with diabetes mellitus was 7 kg more than those in other groups, and delivery occurred one gestational week earlier than in other groups. The amounts of suckled milk produced by patients with diabetes mellitus and hypothyroidism were significantly (p less than 0.05) less than those in other groups; there was no significant difference in milk productions in the other groups. One month after delivery, 35.5% of the babies in the diabetic group were receiving complete breast-feeding, which was significantly (p less than 0.05) lower than the percentages (52-55%) in the other groups. These data suggest that neonatal suckled milk volume in diabetic women is decreased, and that hypothyroidism may influence the initiation of lactation even when the patients are euthyroid due to treatment.

Adult↗
PubMed1989

[The evaluation of simple estimation method of prostate size by transabdominal ultrasound].

We evaluated 107 patients who were diagnosed as benign prostatic hypertrophy preoperatively and underwent transurethral resection of the prostate. We obtained the maximum cross section of the adenoma by transabdominal scanning using a real-time large-sized convex scanner and a 3.5 MNz. transducer. Regarding the adenoma as an ellipsoid with revolution around its transverse axis, 2 diameters (breadth and height) were measured with transverse scan (a and b, respectively). We then calculated the values of the estimated size of the adenoma according to the formula for a spheroid. V = (pi/6) ab2. Thus the calculated weight were correlated with the resected weight of the specimen after a complete transurethral resection of the prostate. As a result, the sonographic estimation provided a high correlation coefficient: r = 0.956. The result suggested that our method of transabdominal ultrasonography in the preoperative evaluation of the prostatic size was rapid, simple and noninvasive, was well adapted for screening sufferers from prostatic diseases, and gave preoperative information for transurethral resection of the prostate and other surgical operation.

Aged↗
PubMed1986

Transplantability and sensitivity to natural killer cells of aclarubicin-resistant murine lymphoma.

DBA/2 mice implanted i.p. with an aclarubicin (ACR)-resistant subline of L5178Y cells survived 4- to 5-fold longer than those with the parental cells; and animals with the Adriamycin- or bleomycin-resistant subline displayed an intermediate survival period. The i.p. treatment of mice with cyclophosphamide markedly enhanced i.p. growth of the ACR-resistant cells, suggesting that a certain host defense mechanism participates in the lower transplantability. In vitro, the ACR-resistant subline showed much higher sensitivity to natural killer cells. The i.p. pretreatment with anti-asialo-GM1 antibody markedly reduced the mean survival period of mice implanted i.p. with the ACR-resistant cells, suggesting that natural killer cells play an important role in the defense against transplantation of the ACR-resistant cells.

Aclarubicin↗
PubMed1985

Production of systolic anterior motion of the mitral valve in dogs.

Production of an experimental preparation of systolic anterior motion (SAM) of the mitral valve was attempted for the purpose of clarifying its causal factors. Fourteen thoracotomized dogs under pentobarbital anesthesia were administered dobutamine, and the echocardiogram, left ventricular pressure, and aortic pressure of each were simultaneously recorded. In two of the dogs in which SAM was produced, two-dimensional echocardiograms were also obtained. Although SAM was absent in all 14 dogs before the administration of dobutamine, it appeared in nine of them after the drug was given. In seven of these dogs, the magnitude of SAM and outflow pressure gradient varied in a dose-dependent manner. No signs of asymmetric septal hypertrophy were observed in any of these dogs. SAM tended to occur even when there was no reduction in preejection period when narrowing of the left ventricular outflow tract was observed. On the two-dimensional echocardiograms, the position of coaptation of the mitral valve was shifted closer to the base of the anterior leaflet in the presence of dobutamine-induced SAM than before the drug was administered. Although the left ventricular cavity became narrow, it was not completely obliterated. This study demonstrates that experimental preparations of SAM can be produced by the administration of dobutamine with a relatively high success rate in normal dogs, and that experimental SAM is accompanied by an outflow tract pressure gradient.

Animals↗
PubMed1985

[Malignant change of duodenal adenoma--a case report and review of the literature].

A 69-year-old woman with a large crater-forming carcinoma of the duodenal bulbus which was associated with a prominent tumor of tubulovillous adenoma in immediate proximity is reported. Histologically, an adenoma-carcinoma sequence was strongly suggested. A review of the literature from both Japan and other countries, after reclassification of histologic patterns, suggested that tubulovillous adenoma in the duodenum may be predominant as compared with that of the colon.

Adenoma↗
PubMed1985

[Noninvasive estimation of pressure gradient in the left ventricular outflow tract: an experimental study].

The relationship between systolic anterior motion of the mitral valve (SAM) and left ventricular outflow pressure gradient (PG) was examined in five dogs with experimentally-produced SAM. A total of 155 heart beats including 29 post-extrasystolic beats with various PG were analyzed. Correlations of PG with the time from the onset of left ventricular ejection to the onset of SAM-septal contact (SSC), SSC divided by ejection time (ET) (SSC/ET), and SSC/ET multiplied by the pre-ejection period (PEP) (PEP X SSC/ET) were obtained. The relation between the natural logarithm of PG (InPG) and SSC/ET was expressed by the linear regression equation: InPG = -5.16X + 5.19, with the correlation coefficient (r) of -0.88 for total 155 beats (r ranged from -0.75 to -0.96 for each dog), and the relation between InPG and PEP X SSC/ET by the formula of InPG = -0.075X + 5.35, with the r of -0.91 for total 155 beats (r ranged from -0.84 to -0.95 for each dog). These results indicated that the time from the onset of aortic ejection to the onset of SAM-septal contact is strongly dependent on the degree of PG.

Animals↗
PubMed1984

[Minute gallbladder cancer--case report with suggestions regarding a possibly unique histogenesis].

A 35-year-old woman with minute gallbladder cancer is presented. Cholecystectomy for gallstones resulted in recurrent colic lasting for a few years. Examination of the resected bladder under a dissection microscope disclosed a minute polypoid tumor with cylindroid appearance measuring 2.0 X 0.5 mm; it was located on a thin membraneous stalk in the neck region. Histologically, the tumor consisted chiefly of well-differentiated adenocarcinoma, in its periphery there were adenomatous residues; the stalk was free of neoplastic change. Blood group substances were completely absent in the cancerous tissues, they were present in adenomatous tissues. We hypothesize that the present cancer derived from the minute gallbladder adenoma via malignant change at an early stage development, suggesting a unique mode for an adenoma-carcinoma sequence in the gallbladder. The present case is believed to be the smallest cancer among reported cases and we propose to define minute gallbladder cancer as that less than 5 mm in maximum diameter.

Adenocarcinoma↗
PubMed1983

Fiberoptic bronchoscopic photoradiation in experimentally induced canine lung cancer.

The potential of diagnostic and therapeutic applications of a system using hematoporphyrin derivative (HpD) and laser photoradiation for the localization and treatment of canine lung cancer experimentally induced in the bronchi was studied. Seven cases of canine invasive squamous cell carcinoma were used in this experiment. A dose of 2.5-3.0 mg/kg body weight HpD was administered intravenously in each dog forty-eight hours prior to examination for fluorescence. The violet light source was a krypton ion laser beam. The beam was transmitted via a quartz fiber inserted through the fiberoptic bronchoscope, and an image intensifier was used to detect the fluorescence from the bronchial foci. An argon dye laser was used for treatment of the foci with red light. Six of seven dogs with squamous cell carcinoma revealed fluorescence at the foci. Conversely, the bronchi of controls, consisting of normal dogs, showed no fluorescence. Three dogs with squamous cell carcinoma received treatment. The therapeutic system consisted of photoradiation with an argon dye laser beam also transmitted via a quartz fiber inserted through the fiberoptic bronchoscope and a dose of 2.5-3.0 mg/kg body weight HpD was administered intravenously 72 hours before the procedure. All carcinoma cases showed complete responses.

Animals↗
PubMed1983

A regurgitant jet and echocardiographic abnormalities in aortic regurgitation: an experimental study.

Acute aortic regurgitation was created experimentally in 21 mongrel dogs to examine the relationship of the regurgitant jet to observed echocardiographic findings. The direction of the regurgitant jet was studied by echo contrast injections in the aortic root. Diastolic fluttering of the anterior mitral leaflet (AML) was noted in all 21 dogs irrespective of direction of the jet. Diastolic fluttering of the interventricular septum (IVS) was noted in six of the seven dogs with a tear of the noncoronary cusp and in one of seven dogs with lesions in the left coronary cusp. In all seven dogs with echocardiographically demonstrated IVS fluttering, a regurgitant jet impinged on the anterior part of the IVS. Amplitude of the AML excursion was not significantly different from control when the lesions involved the noncoronary or the left coronary cusps. However, all seven dogs that had a lesion in the right coronary cusp demonstrated a significant reduction in the amplitude of the AML excursion. The regurgitant jet in these dogs impinged uniformly on the AML. We conclude that diastolic fluttering of the AML is uniformly observed and unrelated to the direction of the regurgitant jet, diastolic fluttering of the IVS is caused by the regurgitant jet impinging upon the IVS, and amplitude of the AML may be reduced as a result of a jet impingement of the AML.

Animals↗