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Biomedical subjects

T Maeda

Publications and source records attributed to T Maeda.

At least 1,153 records · Page 64Linked to original sources
PubMed1986

Histochemical studies on human placental and chorionic monoamine oxidase.

A new coupled peroxidation method for detection of monoamine oxidase was applied to human chorionic and placental tissues of various weeks of gestation. With this new method, the precise localization of monoamine oxidase activity could be determined and the two isotypes of the enzyme could be identified using selective inhibitors. Significant monoamine oxidase activity was observed in syncytiotrophoblasts of fine villi and budding villi. Monoamine oxidase activity in chorionic and placental tissues remained similar in intensity and localization throughout pregnancy. Only one type of monoamine oxidase, type A, was found in the placenta. The functional role of monoamine oxidase is discussed.

Chorion↗
PubMed1986

[Localization of cholinergic neurons in the cat lower brain stem].

The localization of cholinergic neurons in the cat lower brain stem was determined immunocytochemically with a monoclonal antibody against choline acetyltransferase (ChAT), the acetylcholine synthesizing enzyme. ChAT-positive neurons were observed in four major cell groups: cranial nerve motor and special visceromotor neurons: parasympathetic preganglionic visceromotor neurons; neurons located in the ponto-mesencephalic tegmentum including area X (or pedunculopontine tegmental nucleus), nucleus laterodorsalis tegmenti (Ldt) of Castaldi, and peri-locus coeruleus alpha (peri-alpha); and neurons located in nucleus reticularis magnocellularis (Mc) and adjacent nucleus reticularis gigantocellularis (Gc) of the medulla.

Animals↗
PubMed1986

[Studies on oral-adjuvant chemotherapy of uterine cervical cancer after surgical treatment].

To improve the postoperative survival rate of patients with cervical cancer, those with clinical stage Ib or above were treated with adjuvant chemotherapy (oral Tegafur). The drug sensitivity of cultured cervical epidermoid cancer cells was tested with 5-fluorouracil (5-FU), an active derivative of Tegafur. The cumulative rate of recurrence of the group treated with adjuvant chemotherapy was 28.4% (19/67 cases), significantly lower than that of the untreated control group 69.8% (44/63 cases) (p less than 0.01). The rate of recurrence for the two groups was evaluated with Cox's regression models. The rate of recurrence of the treated group was about 50% that of the untreated group. The drug sensitivity of the cultured cancer cells was investigated with a colony forming assay, and a dose-response curve was obtained for the time-dependent anticancer drug. The inhibition of DNA synthesis peaked after 24 to 72 hours of incubation with 5-FU at 0.1 to 0.5 micrograms/ml, but the peak appeared in 4 to 8 hours at 1.0 to 10.0 micrograms/ml. Morphologic changes occurred after 192 hours of incubation at 0.1 microgram/ml. Investigation of the drug sensitivity by cell kinetics disclosed prolongation of the cell cycle after 144 hours at 0.1 microgram/ml and inhibition of cell cycle progression after 48 hours at 10.0 micrograms/ml. Thus, adjuvant chemotherapy with Tegafur reduces the rate of recurrence to about 50% in postoperative patients with cervical cancer. This finding was also supported by an experimental study.

Adenocarcinoma↗
PubMed1986

[Indications for aortocoronary bypass operation in elderly patients: medical point of view].

Aorto-coronary (A-C) bypass operations were performed in 20 patients aged 68 to 78 years, and the indications for this operation were discussed retrospectively. The subjects consisted of 14 patients successfully operated and six patients unsuccessfully operated (death 3, graft occlusion 2, perioperative infarction 1). The results were as follows: Average age: There was no difference between the successful group (71.1 +/- 3.3 years; mean +/- SD) and the unsuccessful group (70.3 +/- 2.9 years). Coronary arteriographic findings: The average number of narrowed branches (greater than or equal to 75% stenosis) was 4.3 +/- 3.0 in the successful group (triple vessel disease in 12 cases and double vessel disease in four) and 2.7 +/- 0.5 in the unsuccessful group (triple vessel disease in four and double vessel disease in two), showing no significant difference between the two groups. Nine patients (64.3%) in the former group and one (16.7%) in the latter group had significant left main coronary artery disease (greater than or equal to 50% stenosis). Hemodynamic findings: Ejection fractions of less than 40% existed in three patients (50%) solely in the unsuccessful group; two of whom died. Left ventricular end-diastolic pressures of 30 mmHg or more existed in two cases (33.3%) only in the latter group. Other cardiac findings: Left ventricular end-diastolic dimension of 55 mm or more was found in one (7.1%) successful case and four (66.7%) unsuccessful cases. 201Tl-scintigrams showed a dilated left ventricular cavity in one case (7.1%) in the former group and two (33.3%) in the latter. Functions of other organs: Forced expiratory volume 1.0% or % vital capacity less than 70% was recognized in two cases (33.3%) only in the latter group. A level of serum creatinine more than 1.5 mg/dl was seen in only one case in the latter group. A case with advanced diabetes mellitus was present in the unsuccessful group, and this patient died of diabetic coma. A-C bypass operations are indicated for elderly patients when they have good cardiac function and have no complications of the kidneys, lungs and other organs. It is presumed that grafting the main coronary branches, thereby shortening the time of cardiopulmonary arrest prevents postoperative complications.

Aged↗
PubMed1986

[Functional significance of left ventricular distortion in patients with right ventricular volume or pressure overloading].

To evaluate the effects of left ventricular (LV) distortion on its pump function, the LV cavity shape was analyzed by two-dimensional echocardiography in normal subjects and in patients with right ventricular (RV) volume or pressure overload. The functional significance of LV distortion in the short-axis sections was evaluated by an index of the efficiency of ejection (E) of endocardial circumferential fiber length (ECL) shortening in reducing LV cavity area during systole; E = measured systolic area reduction/ideal systolic area reduction X 100 (%), where an ideal area at end-diastole or end-systole was computed for the measured ECL, assuming its shape to be perfectly circular (ideal area = ECL2/4 pi), and then an ideal systolic area reduction was determined. E at the chordal level was termed Ech. In patients with atrial septal defect (ASD), the LV cavity was distorted at end-diastole and became more circular at end-systole. Since this characteristic change during systole diminished the E, and the values of E at the chordal level (Ech) were significantly lower in ASD than those in normal subjects (89.4 +/- 4.4% vs 98.3 +/- 0.8%, p less than 0.001), strongly suggesting impairment of the efficiency of LV pump function in ASD. In patients with pulmonary hypertension, the LV cavity was more distorted at systole, and a decrease in cavity area at end-systole with the distorted LV contributed to increased systolic area reduction. Thus, the values of Ech in this group exceeded 100% in five of nine patients (103.8 +/- 12.3%). In other words, when marked RV systolic overload exists, an increase in LV systolic area reduction due to progressive LV compression will occur against LV systolic pressure. This phenomenon suggests the existence of "cardiac massage on the LV by the RV with elevated pressure". In conclusion, it was strongly suggested that the efficiency of LV pump function is modulated by RV overload through dynamic changes in the LV shape.

Adolescent↗
PubMed1986

[Echocardiography in a case of acute tuberculous pericarditis which progressed to constrictive pericarditis].

A case of acute tuberculous pericarditis with massive pericardial effusion progressed to constrictive pericarditis under echocardiographic observation during one year. This 59-year-old man was hospitalized because of dyspnea. On admission, his physical examination revealed a paradoxical pulse, engorged jugular veins, hepatomegaly, and pitting edema in the pretibial regions. Chest radiography revealed an enlarged cardiac silhouette and a marked left pleural effusion. His echocardiogram showed a massive pericardial effusion. A biatrial echogram recorded by esophageal echocardiography showed a massive pericardial effusion anterior to the right atrial free wall. Echocardiography performed four months after commencing therapy revealed a reduction in the pericardial effusion, and normal motion of the interventricular septum and posterior wall. However, the motion of the interatrial septum was already abnormal and the excursion of the right atrial free wall was markedly reduced. These finding were similar to those in constrictive pericarditis, as previously reported. Eleven months after admission, both conventional and esophageal echograms showed findings typical of constrictive pericarditis. Thus, in this case, the abnormal biatrial dynamics were recognized earlier than the abnormal left ventricular wall motion.

Echocardiography↗