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Biomedical subjects

T Aihara

Publications and source records attributed to T Aihara.

At least 109 records · Page 6Linked to original sources
PubMed1992

Expression of recombinant human follicle-stimulating hormone receptor: species-specific ligand binding, signal transduction, and identification of multiple ovarian messenger ribonucleic acid transcripts.

The ligand specificity and biochemical properties of the human (h) FSH receptor are poorly characterized due to the low abundance of these receptors and the limited availability of human tissues. Using a fragment of rat FSH receptor cDNA, we screened a human testicular cDNA library and obtained a FSH receptor cDNA covering the entire amino acid-coding region. After transfection of a human fetal kidney cell line (293) with the hFSH receptor cDNA, radioligand receptor analysis revealed the presence of high affinity (Kd, 1.7 x 10(-9) M) FSH-binding sites on the plasma membrane. Both recombinant and wild-type hFSH displaced [125I]hFSH binding, with ED50 values of 25 and 70 ng/ml, respectively, whereas hLH, hCG, and hTSH were ineffective. Although human, rat(r), and ovine FSH as well as equine CG competed for rat testicular FSH receptor binding, only hFSH and rFSH interacted effectively with the recombinant hFSH receptor, suggesting that species-specific ligand recognition exists between human and rodent receptors. After incubation of transfected cells with hFSH, but not recombinant hLH or hCG, a dose-dependent increase (ED50, 10 ng/ml) in extracellular cAMP accumulation was observed, indicating a functional coupling of the expressed human receptor with the endogenous adenyl cyclase. In cells cotransfected with the FSH receptor expression plasmid and a luciferase reporter gene driven by the promoter of a cAMP-responsive gene, treatment with hFSH, but not hCG, resulted in a dose-dependent increase in luciferase activity. Northern blot analysis using a cRNA probe derived from the human receptor cDNA indicated the presence of multiple FSH receptor mRNA transcripts (7.0, 4.2, and 2.5 kilobases) in RNA prepared from human follicular phase ovary, but not from human corpus luteum or placenta. Additionally, two FSH-binding sites of 76 and 112 kilodaltons were detected in transfected 293 cells after ligand/receptor cross-linking and sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis. These results demonstrate the expression of functional hFSH receptor with unique ligand specificity and provide new data on the biochemical properties of the human receptor at the mRNA and protein levels.

Animals↗
PubMed1992

Sacrococcygeal chordoma with a malignant spindle cell component. A report of two autopsy cases with a review of the literature.

Two autopsy cases of sacrococcygeal chordoma which showed sarcomatous components in the primary and metastatic tumors are reported. Case 1 was a 48-year-old female who died 9 years after the development of the initial symptoms. Autopsy findings showed metastatic tumors consisted of malignant tumor cells similar to fibrosarcoma and osteosarcoma. Case 2 was a 63-year-old male who died 11 years after the development of the initial symptom. At autopsy only sarcomatous tumors resembling malignant fibrous histiocytoma (MFH) were observed in the metastatic lesions. Both cases were treated with irradiation. It is suggested that the appearance of sarcomatous tumor in current two cases of chordoma might be due to the phenomenon of tumor progression closely associated with irradiation therapy. These two cases can be categorized as "chordoma with a malignant spindle cell component" in a sense that highly malignant sarcomatous components existed in conjunction with chordoma in the primary tumors.

Autopsy↗
PubMed1991

Negative U wave during percutaneous transluminal coronary angioplasty.

To clarify the clinical significance of the negative U wave during acute myocardial ischemia, the appearance of the U wave and ST-segment elevation on electrocardiography during percutaneous transluminal coronary angioplasty (PTCA) of the left anterior descending artery (LAD group: 11 patients) or right coronary artery (RCA group: 18 patients) was studied. During PTCA, U-wave inversion (newly developed negative U wave, and increased negativity of the pre-existing negative U wave) was observed in 37 (90%) of 41 patients in the LAD group and in 16 (89%) of 18 patients in the RCA group. The incidence of ST-segment elevation was similar to that of U-wave inversion; however, U-wave inversion appeared before detectable ST-segment elevation in 20 patients (49%) in the LAD group and in 4 patients (22%) in the RCA group. Moreover, U-wave inversion was observed frequently in a wider range of leads than ST-segment elevation. These results suggest that the U wave is a more sensitive indicator of myocardial ischemia than ST-segment elevation in some patients, and that a negative U wave may be produced by a different mechanism than that which produces ST-segment deviation, although both are related to myocardial ischemia.

Angioplasty, Balloon, Coronary↗
PubMed1991

[Tolerance to a sustained release form of isosorbide dinitrate: comparison between 20 mg four times and 40 mg twice-daily administrations].

Attenuation of antianginal effects of oral isosorbide dinitrate in a sustained release from (ISDN-SR) were studied using the treadmill exercise test in eleven patients with stable exertional angina and a positive exercise test. We compared the four-time-daily administration of 20 mg with a twice-daily regimen of 40 mg for 10 days using the double-blind, crossover method. On the 1st day of the administration, with both regimens, the treadmill walking time, the time to 1mm and 2mm ST depression, and several hemodynamic parameters increased significantly. These improvements were reduced gradually on day 5 and day 10 after the administration. In the comparison between the four-time-daily and two-time-daily regimens, the former application showed clearer antianginal and hemodynamic effects than the latter regimen, but these effects were attenuated more markedly in the four-time daily administration. With both dosage regimens, the plasma ISDN concentrations increased gradually. With the long-term four-time-daily regimen, the time-to-time changes of the ISDN concentration were smaller each day. These data suggest that tolerance to oral ISDN-SR exists even if it is applied only two time daily, but its degree is less than when a four-time-daily dose in administered.

Administration, Oral↗
PubMed1991

[Wrapping operation for Stanford type A acute dissecting aneurysms].

Four cases of Stanford type A acute aortic dissection were treated by wrapping operation. After careful dissection between the dilated ascending aorta and right pulmonary artery, 8 mm woven Dacron vascular prosthesis was passed around the aorta and tightened. Further enforcement wrapping was carried out using several prostheses from aortic root to the innominate artery. We call this technique "wrapping operation". Emergent operations were performed on all patients because of cardiac tamponade, 6.8-33 hours after the onset of dissection. Three patients are doing well 17-39 months after the operation, but only 1 patient died early postoperative period because of DIC and multiple organ failure. And 2 patients was showed closure of entry of the ascending aorta by the postoperative aortography. We think that the wrapping operation is a useful technique for the patients of ruptured Stanford type A acute dissecting aneurysms.

Aortic Dissection↗
PubMed1991

[A case of left atrial giant thrombus which appeared in a short period].

We reported a case with left atrial giant thrombus (LAGT) which appeared over a period of six months. The patient was a 65-year-old woman who came to our hospital complaining of syncopal attack. Her electrocardiogram showed atrial fibrillation with very slow ventricular response, and there was cardiac arrest for 1500 ms, mitral stenosis and regurgitation, aortic and tricuspid regurgitations were recognized in the echocardiogram. By coronary angiography, 90% stenosis in the left circumflex artery (LCX) was found, and using transseptal left atrium heart catheterization, pressure gradient from the left atrium to the left ventricle was also measured. We diagnosed that her valvular diseases were mild. To protect her from unconsciousness and heart failure, a permanent pacemaker was implanted and PTCA for LCX lesion was performed. After six months, we found LAGT by echocardiography. It is very rare that LAGT is formed in a short period. We suggested that the changes of hemodynamics caused by transseptal left atrial catheterization or the permanent pacemaker implantation effected the formation of the LAGT.

Aged↗
PubMed1991

[The step to improve the operative outcome in patients with severe valvular heart disease].

In an effort to improve the operative outcome in severe valvular heart disease, we investigated the effects of low-dose infusion of dopamine and dobutamine up to the day of operation. New York Heart Association Functional Class was improved significantly before operation, as compared with at the time of admission. It was possible to perform operation on individual patients when their physical condition seemed to be at their best. In patients with fear of postoperative renal failure, hemodialysis was combined during cardiac surgery to prevent failing to renal dysfunction after operation. As the result of these procedures, we were able to obtain satisfactory result. In patients with severe valvular heart disease, the preoperative combined infusion of dopamine and dobutamine, and hemodialysis during cardiac surgery to prevent postoperative renal dysfunction seemed to improve the operative outcome.

Adult↗
PubMed1990

[Relapsed stage I neuroblastoma successfully treated by allogeneic bone marrow transplantation in second remission: case report of a 7-year-old girl].

Stage I neuroblastoma in a seven-year-girl have had local recurrence with bone metastasis. Second surgery was performed after the aggressive chemotherapy including cisplatin, VP16, cyclophosphamide, vincristine and doxorubicin. She underwent allogeneic bone marrow transplantation from her HLA identical brother, following the preparative regimen consisting of high-dose melphalan and total body irradiation (12 Gy). Clinical course after the transplantation was uneventful. She is still alive with no evidence of disease for twenty-eight months after the transplantation. It is suggested that bone marrow transplantation is an effective way of therapy even in a patient with relapsed neuroblastoma.

Adrenal Gland Neoplasms↗
PubMed1990

[Primary coronary artery dissection: its incidence and genesis studied by clinical and coronary angiographic findings].

The incidence and genesis of primary coronary artery dissection which occurred spontaneously in the coronary artery system were elucidated in this study. We examined clinical and coronary angiographic features of the patients who presented this dissection. Primary coronary artery dissection was observed in 23 (0.43%) of 5,400 consecutive patients with ischemic heart disease undergoing coronary angiography. The basic diseases were myocardial infarction in 17 cases and angina pectoris in 6. Sixteen patients (70%) had smoking habits, which might be related to this disease. The dissection of the right coronary artery in 12 cases, of the left anterior descending artery in 10, and of the left circumflex artery in only one was found. All lesions occurred in the proximal positions of the coronary branches. Seven (30%) of all cases had fixed coronary stenosis in other coronary branches. The other cases had "one-vessel" disease. Seventeen patients were treated medically, 5 had PTCA therapy and one had CABG operation. All the patients, except one who died of cancer are surviving in a 3.8-year follow-up. Patients can be divided etiologically into three groups. The first was comprised of those in the post- or peri-partum period. The second was those associated with coronary vasospasm, and the third was those with atherosclerotic coronary artery disease. The third group was the most frequent.

Adult↗
PubMed1990

[Cytogenetical study on the etiology of partial mole].

The cytogenetical etiology of partial mole (PM) was studied by means of the Q-banding technique in 49 cases during the period between Sep. 1976 and Nov. 1986. Moreover, histological examinations were performed in 39 cases concentrating on the existence of fetal components and trophoblastic hyperplasia, etc. The results were as follows. 1. Karyotype analysis showed triploidy (24 cases), normal diploidy (10 cases), trisomy (9 cases) and other anomalies (mosaic, translocation etc.) (6 cases). These results are quite different from those of many western authors, who reported that most cases of PM are triploidy. 2. The criteria of PM in Japan differ from those of WHO Scientific Group in regard to trophoblastic hyperplasia. 3. Our cases were reclassified on the basis of the definition drawn up by the WHO Scientific Group. Nevertheless, the rate of triploidy was only 54.5%, which is lower than that reported by many western authors. These results show that the development of PM cannot be explained cytogenetically at present, in contrast with complete mole.

Diploidy↗
PubMed1990

[Coronary artery disease in patients with abdominal aortic aneurysm].

Selective coronary angiography to determine the prevalence of coronary artery disease (CAD) has been performed in patients with abdominal aortic aneurysm (AAA). Thirty patients in this series consisted of 26 men and 4 women with an age range of 48-87 years (mean +/- SD: 67.5 +/- 8.2 years). As the atherosclerotic risk factors, cigarette smoking was present in 19 patients (63.3%), hypertension was in 18 (60%), hypercholesteremia was in 10 (33.3%), and diabetes mellitus was in 2 (6.7%). Cerebral vascular disease was present in 11 patients (36.7%). Regarding CAD, angina pectoris or old myocardial infarction was found in 9 patients (30%), and abnormal electrocardiography (ECG) was in 16 patients (53.3%). Coronary angiography prior to operation of AAA was performed to 22 patients (73.3%), and 15 patients (68.2%) among them had significant coronary artery stenosis, and 9 patients underwent myocardial revascularization (4 CABG, 5 PTCA). CAD was frequently complicated both in patients without symptoms or ECG abnormalities and in less than 65-year patients. In order to prevent fatal myocardial infarction, we recommend routine coronary angiography to patients with AAA. And if necessary, myocardial revascularization must be indicated prior to aneurysmectomy.

Aged↗
PubMed1990

[A case of myonephropathic-metabolic syndrome after urgent aortic valve re-replacement due to prosthetic valve thrombosis].

Acute cardiac failure due to prosthetic valve thrombosis is a rare, but lethal complication after cardiac valve replacement. A 40-year-old female admitted to our hospital, because of cardiac failure after aortic valve replacement with a #21 Björk-Shiley valve in 1975. After admission, echocardiography showed thrombotic obstruction of the prosthetic valve, and we underwent urgent aortic valve re-replacement. Postoperative period, she was complicated with myonephropathic-metabolic syndrome (MNMS). But, we performed intermittent veno-venous hemofiltration (IVVH) in early period, and successfully could save her life and her lower limb.

Adult↗
PubMed1990

[Single photon emission computed tomography of the brain in Sturge-Weber syndrome using N-isopropyl-p-[123I] iodoamphetamine--a comparative study with X-ray computed tomography].

Single photon emission computed tomography (SPECT) of the brain using N-isopropyl-p-[123I] iodoamphetamine (123I-IMP) was performed in 11 children with port wine stain on the face or head, aged 1.0-14.2 years at investigation. Four cases without neurologic symptoms had no specific abnormality on SPECT and X-ray computed tomography (CT). In 4 cases of so-called Sturge-Weber syndrome with developmental quotients (DQ) or intelligence quotients (IQ) more than 80 and the neurologic symptoms consisting of seizures and hemiplegia, SPECT showed localized reduction of IMP accumulation, and CT exhibited calcification, atrophy and enhancement in 2 cases of 3 with contrast medium infusion in the same areas. In 3 cases with DQ of 50-60 and severer neurologic symptoms, SPECT showed diffuse reduction or defect of IMP accumulation in the ipsilateral hemisphere, and CT exhibited remarkable atrophy, calcifications and enhancement in 2 cases with contrast medium infusion in the same hemisphere. In one case with severe neurologic symptoms, SPECT performed at an early stage showed high IMP accumulation in the ipsilateral hemisphere.

Adolescent↗
PubMed1989

Acute myocardial infarction due to coronary spasm associated with L-thyroxine therapy.

A 63-year-old man with hypothyroidism is described. He had been receiving L-thyroxine therapy following mitral valve surgery. About three weeks into the therapy regimen, he complained of severe retrosternal chest oppression. Electrocardiographic findings and laboratory data indicated a diagnosis of acute myocardial infarction due to the L-thyroxine therapy. Emergency selective coronary angiography was performed. Comparing his coronary angiograms with those obtained before surgery indicated a severely spastic left coronary artery. We believe this is the first report of myocardial infarction due to coronary spasm, demonstrated by angiography associated with L-thyroxine therapy.

Angiography↗
PubMed1989

Magnetocardiographic studies of ventricular repolarization in old inferior myocardial infarction.

Isomagnetic maps of 50 normal subjects (control group) and 23 patients with old inferior myocardial infarction (IMI group) were recorded in order to analyse T wave abnormalities in inferior myocardial infarction. The T wave of the magnetocardiogram (MCG) in the control group showed negative deflections in the left upper portion and positive deflections in the right lower portion, thus resulting in a T vector directed leftward and inferiorly. The T wave of the IMI group was flat or positive in the left upper portion and flat or negative in the right lower portion, suggesting a T vector directed superiorly. In addition, opposing dipoles were observed in 36.4% of the IMI group; i.e. one directed superiorly, presumably due to inferior myocardial ischaemia, and the other directed inferiorly due to normal repolarization. Localized T vector abnormalities could be detected by the MCG in some cases, in which coronary T waves of the standard electrocardiogram had returned to normal. Furthermore, multiple dipoles were more frequently observed in the isomagnetic map than in the isopotential map (5 vs. 15; P less than 0.01). These results suggest that the MCG is helpful in diagnosing myocardial ischaemia when this is not detectable on the electrocardiogram.

Adult↗
PubMed1989

[Electrocardiograms during acute occlusion of the left circumflex artery as compared with that of the right coronary artery].

To assess the characteristic electrocardiographic (ECG) ST changes during acute occlusion of the left circumflex artery (LCX), we observed ECG changes during percutaneous transluminal coronary angioplasty (PTCA) of the LCX and compared the results with those obtained during right coronary angioplasty. Results were as follows: 1. In the 30 patients who had LCX angioplasty (group LCX), ST-segment elevation occurred most frequently in lead V6 (67.7%) and in lead III (46.7%), but rarely in leads and aVL. ST depression occurred most frequently in lead V3 (80.0%) and in lead V2 (73.3%), but rarely in other leads except for leads I and aVL (23.3%, 33.3%). 2. Four types of ST change in lead combinations were observed. These included: (1) ST elevation in the inferior leads (II, III and aVF), (2) ST elevation in the lateral leads (V5 and V6), (3) ST depression in the anterior leads (V2-V4) and (4) ST depression in the high lateral leads (I and aVL). In group LCX, nine cases (30.0%) manifested all four changes, and six cases (20.0%) revealed only ST depression in the anterior leads without ST changes in other leads. 3. ST depression in the anterior leads and ST elevation in the inferior and lateral leads were observed in nearly equal frequency in patients who received PTCA at the proximal site (Seg. 11) and at the distal site (Seg. 13) in the group LCX. However, ST depression in the high-lateral leads was more frequently observed in the distal than in the proximal cases (66.7% vs 33.3%).(ABSTRACT TRUNCATED AT 400 WORDS)

Acute Disease↗
PubMed1989

Chronic effects of nicorandil on exercise tolerance in patients with stable effort angina pectoris.

To examine the chronic effects of nicorandil, a new coronary vasodilator, on exercise tolerance, we gave this drug for ten days at 15 mg/day orally in three divided doses to 10 patients with stable effort angina. An increase in exercise capacity by more than 1 stage of modified Bruce's protocol was observed in 6 of 10 patients on the 5th and 10th day after the administration. The exercise duration was significantly prolonged from 294 +/- 86 sec (mean +/- SD) before the administration to 363 +/- 106 sec and 405 +/- 139 sec on the 5th and 10th day after the administration, respectively. With nicorandil administration, the time to 0.1 mV of ST-segment depression was also significantly delayed from 3.1 +/- 1.9 minutes to 4.5 +/- 2.6 minutes on the 10th day. On the other hand, systolic blood pressure, heart rate and pressure rate product did not demonstrate any significant change before and after the administration. These results indicate that oral nicorandil of 5 mg 3 times a day can chronically increase exercise tolerance without decreasing myocardial oxygen consumption in patients with stable effort angina.

Adult↗