Search PubMed⌕ Search

Biomedical subjects

K Taniguchi

Publications and source records attributed to K Taniguchi.

At least 685 records · Page 38Linked to original sources
PubMed1988

Serial analysis of spontaneous and induced ventricular arrhythmias in a canine model of myocardial infarction.

To study the time course of spontaneous and induced ventricular arrhythmias after myocardial infarction (MI), 20 dogs underwent ligation of the left anterior descending coronary artery and temporary occlusion and reperfusion of the obtuse marginal branch. There were 5 early deaths (less than 24 hours) due to spontaneous ventricular fibrillation (VF). All 15 survivors exhibited spontaneous ventricular tachycardia (VT) up to day 3 with the shortest cycle length occurring at 17 hours after MI (232 +/- 11 msec: mean +/- SEM). The grade of arrhythmia complexity was decreased after day 4 compared to day 1 (p = 0.049), and the number of ventricular premature complexes was reduced after day 6 (1700 +/- 1390/hour) compared to day 1 (9500 +/- 640/hour, p = 0.042). Serial electrophysiologic studies were carried out on days 8, 15, 22, and 29 via an implanted antitachycardia pacemaker using 1 to 3 extrastimuli and rapid ventricular pacing (RVP). On day 8, VT was inducible in 7 dogs (46%), VF in 4 (27%), and 4 dogs (27%) exhibited a negative response. On day 15, 3 more dogs became negative, and all previously negative dogs displayed negative responses. From day 15, the inducibility of VT/VF remained "constant" using RVP. However, inducibility by triple extrastimuli declined week by week until day 29. Stepwise logistic regression analysis of 20 variables selected the mass of the MI as the only independent predictor of inducible VT/VF by multiple extrastimuli and RVP after day 15 (p = 0.049). Thus significant time- and mode-dependent changes in inducibility of VT/VF occur during the early phase after MI.

Animals↗
PubMed1988

The use of evoked endocardial response for assessment of antiarrhythmic drug effects on myocardium.

The technique "asymmetric biphasic stimulation" which paces the heart and neutralizes the post-stimulus polarization at the electrode-tissue interface allows for the recording of the entire evoked endocardial response via a single electrode for both pacing and recording. Using this system the effects of antiarrhythmic drugs, procainamide and N-acetylprocainamide, on the myocardium were studied in 20 dogs. Before and during the five-step drug infusion, the evoked endocardial responses were recorded during bipolar and unipolar at the rates of 120, 150 and 200/min. The plasma concentration of the procainamide ranged from 1.7 to 32.5 mg/l and that of N-acetylprocainamide ranged from 8.1 to 116.1 mg/l. Procainamide significantly prolonged both the depolarization duration and the repolarization duration at a low plasma concentration (Class I antiarrhythmic drug property). N-acetylprocainamide significantly prolonged the repolarization duration at a low plasma concentration, while the depolarization duration was not significantly changed at a low or therapeutic plasma concentration (Class III antiarrhythmic drug property). The prolongation of the depolarization duration by procainamide and N-acetylprocainamide was rate-dependent; the faster the rate the greater the prolongation. This simple and accurate assessment of the antiarrhythmic drug effects on the myocardium may provide a future means for the pharmacologic antiarrhythmic therapy.

Acecainide↗
PubMed1988

[A clinico-statistical study of testicular tumors--a reevaluation of 90 cases at the Nagasaki University Hospital and affiliated hospitals].

We have treated 90 cases of testicular tumors at our institutes from April, 1962 to March, 1986. Of 75 which were germ cell type tumors, 35 were a seminoma, for which the 5-year survival rate was 100% for patients in stage I, and 50% for those in stage III, respectively. Forty cases were non-seminomas, and all cases determined as being in stage I survived for 5 years, whereas 47.6% cases of those in stage III survived for 4.5 years. Thirty-six percent of those with a stage I germ cell tumor were treated with a orchiectomy alone, while other cases also combined radiotherapy and/or chemotherapy. Almost all cases of an advanced tumor received combined retroperitoneal lymph node resection, radiotherapy and/or chemotherapy. Patients with an advanced nonseminomatous tumor showed better a survival rate if they were given CDDP chemotherapy.

Dysgerminoma↗
PubMed1988

Urapidil in patients with severe hypertension and in long-term treatment.

In order to evaluate the usefulness of urapidil in the treatment of severe hypertension and in the long-term treatment of essential hypertension, two open multicentre studies were performed. In one study, 34 outpatients with diastolic blood pressure exceeding 105 mmHg following treatment with a combination of a diuretic and a sympatholytic or a diuretic and a beta-blocker were additionally given 15-60 mg urapidil twice a day for 8 weeks or more. The responder rate was 73.5%. The pulse rate did not change throughout. Side effects such as dizziness and malaise were observed in five patients (14.7%), but they were slight and did not require withdrawal of treatment. The other study included 95 outpatients with essential hypertension (World Health Organization stages I or II), 15-60 mg urapidil twice a day for 1 year or more in monotherapy (n = 48) or in combined therapy with a thiazide (n = 47). Under both therapies, diastolic blood pressure was reduced significantly at week 4, further reduced at week 12 and remained stable until week 52. Responder rates were 82.9% in monotherapy and 78.4% in combined therapy. Two patients (4.2%) taking monotherapy and six patients (12.8%) taking combined therapy were withdrawn due to inadequate blood pressure control or to side effects. These results indicate that urapidil is useful in severe and in long-term hypertension.

Adrenergic beta-Antagonists↗
PubMed1988

T lymphocytes emigrating from the thymus to the spleen during postpartum regulate serum immunoglobulin levels in mice.

We noted an increase of a splenic T-cell population in early postpartum normal mice, but not in thymectomized (Tx) postpartum mice. The T-cell population consisted mainly of Lyt-1+2- cells and exerted suppressive activity in in vitro assays. To determine the in vivo function of these emigrant T lymphocytes during postpartum, we investigated the effect on immunoglobulin levels in the sera of mice, from pregnancy through the postpartum stages. A reduction in serum IgG1 levels in the late postpartum period was subsequent to the transitory elevation of IgG1 levels in early postpartum. However, this reduction of IgG1 was not seen in Tx mice at the late postpartum stage. To confirm the relationship between emigrant T cells and the immunoglobulin level, an adoptive transfer experiment was done. The level of IgG1 was reduced in the sera of recipients to which enriched splenic T cells from 3-day postpartum mice had been transferred. The data from the adoptive transfer experiment provided evidence that the increased T-cell population in mice in the early postpartum period regulates the IgG1 level in the serum. It was also recognized that T lymphocytes with the Lyt-1+2-phenotype, which emigrated from the thymus to the spleen after delivery, were able to suppress the IgG1, IgG2a,IgG2b levels in the serum. In addition, the appearance of the suppressive function of the Lyt-1+2- cells in these IgG subclasses required co-operation with the Lyt-1-2+ cells. Therefore, the thymus-dependent emigrant cells in the periphery in early postpartum mice may play a significant role in controlling immunoglobulin levels in the serum.

Animals↗
PubMed1988

AK cells were developed from NK cells during in vitro culture of allogeneic or F1 anti-parental stimulation: functional conversion in recognizing H-2 expression of target cells accompanied by phenotypical conversion.

In vitro sensitization of (CBA x A)F1 spleen cells for 3 days with allogeneic C57BL cells raised the killer activity to the NK-sensitive YAC-1 target. When (A x C57BL)F1 spleen cells were cultured with parental C57BL cells, the lytic activity to YAC-1, P815 and EL-4 targets occurred on Day 6 after the culture. Phenotypical analyses showed that these culture-activated killer (AK) cells were derived from asialo-GM1+Thy-1-NK cells; however, they expressed Thy-1 antigen but not asialo-GM1 antigen at the effector cell level. Generation of the AK cells was not evident in cultures of spleen cells from mice with a neonatally induced tolerance to stimulator antigen and in those from T-cell-depleted mice. The supernatant of allostimulated culture, which contained a low concentration of IL-2, rendered the above cells capable of evoking AK activity. The H-2-reduced target cells were sensitive to NK cells, but less sensitive to AK cells; on the contrary, the H-2 highly expressed cells (interferon-treated cells) were less susceptible to NK cells but highly susceptible to AK cells. Thus, the relation between NK susceptibility and susceptibility to AK cells is inverse. Our study shows that stimulation with lymphokines causes a functional conversion accompanied by a phenotypical conversion of NK cells. With reference to immunosurveillance, these observations lead to the idea that NK and AK cells represent two functionally distinct but complementary systems involved in cell-mediated immunosurveillance.

Animals↗
PubMed1988

[Minimal requirement for successful late results of valve replacement for aortic regurgitation and aortic stenosis].

This study was consisted of 69 patients undergoing aortic valve replacement for chronic aortic regurgitation (AR) and 29 patients, for aortic stenosis (AS) between 1978 and 1985. There was no operative death. There were 7 late cardiac deaths in AR patients, with preoperative left ventricular end-systolic volume index (LVESVI) greater than 200 ml/m2. None of the 55 patients with an LVESVI less than 200 m/m2 died of cardiac-causes. In AR patients with preoperative LVESVI greater than 200 ml/m2, despite the postoperative reduction of the wall stress, the ejection fraction failed to return to normal, indicating that irreversible myocardial dysfunction was responsible in these patients. There were two cardiac-related deaths in 29 AS patients, who had preoperative LVESVI greater than 100 ml/m2. In postoperative AS patients with LVESVI greater than 100 ml/m2, postoperative contractile function of the left ventricle was poor. In conclusion, minimal preoperative left ventricular function for satisfactory late results and reversal of functional results may be at a lower level was LVESVI 200 ml/m2 in AR patients and 100 ml/m2 in AS patients.

Aortic Valve Insufficiency↗
PubMed1988

Progression of aortic stenosis in the elderly detected by noninvasive methods.

One hundred eighty consecutive male patients, mean age of 64.6 years, who were referred to cardiac catheterization for the evaluation of aortic stenosis (AS), were studied using a noninvasive scoring system. The system is based upon 7 variables including: 1) LVH by ECG, 2) aortic valve calcium by chest x-ray, 3) loudness of A2, 4) Q to peak of murmur, 5) T time of the carotid pulse, 6) LV ejection time and 7) LVH by echocardiography. The scoring system has a range from 0 to 16, and a score greater than or equal to 5 indicates severe AS (valve area less than or equal to 1.0 cm2). Eighteen patients had hemodynamic studies on two occasions. In 3 years progression of stenosis was evident by an increase in the mean aortic valve gradient from 23 +/- 3.4 mmHg to 44 +/- 4.2 mmHg (p less than 0.005). The aortic valve area decreased from 1.4 +/- 0.1 cm2 to 0.76 +/- 0.07 cm2 (p less than 0.005). Noninvasive scores increased in these patients from 2.1 +/- 0.5 to 7.6 +/- 1.0 (p less than 0.005). Fifty-one patients had repeated noninvasive studies. Twenty-two patients, who had mild AS at the initial evaluation, attained a score of greater than or equal to 5 in 3 years, indicating probable progression to severe AS. The mean initial score was 2.3 +/- 0.4, and the score at the end of the mean follow-up period of 3 years was 8.0 +/- 0.6 (p less than 0.005).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1988

Behçet's disease associated with aortic and mitral regurgitation: report of two cases.

Two rare cases of complicating valvular lesions in Behçet's disease are reported. Case 1: A 45-year-old man with combined aortic and mitral regurgitation had perforation of both valves. Six months after aortic valve replacement (AVR) and mitral valvuloplasty, an aortic paravalvular leak developed again, and was treated by surgery using an artificial graft with a prosthetic aortic valve. Case 2: A 40-year-old man with congestive heart failure and inflammatory signs had aortic and mitral regurgitation. Although cardiac medications for heart failure and treatment with methylprednisolone were started, he eventually had successful aortic valve replacement. Valvular disease complicating Behçet's disease is rare; only 15 cases, including our two, have so far been reported. Its rarity is partly because Behçet's disease predominantly involves the venous system, not the arterial system.

Adult↗
PubMed1988

Evaluation of long-term results of bicuspidalization annuloplasty for functional tricuspid regurgitation. A seventeen-year experience with 133 consecutive patients.

Between 1968 and 1985, 133 consecutive patients underwent bicuspidalization annuloplasty for moderate to severe functional tricuspid regurgitation associated with mitral or combined mitral and aortic valve disease. Over this period, the incidence of tricuspid valve replacement was only 2.3% (3/136 patients). There were 18 early deaths (13.5%) in the entire series--three (5.0%) of 60 patients in the last 5 years of the study--and 10 late deaths (8.7%). Actuarial survival rate for the entire series, excluding early deaths, was 91.0% +/- 3.0% at 10 and 17 years. There were seven reoperations (6.1%) on the tricuspid valve, needed because of residual or recurrent mitral valve lesions after the initial operation. Actuarial rates of freedom from reoperation on the tricuspid valve were 93.6% +/- 3.0% (10 years) and 69.7% +/- 16% (17 years) for the entire series: 78% +/- 10% (15 years) for the open mitral commissurotomy plus tricuspid annuloplasty group (44 patients); 90% +/- 9.0% (15 years) for the mitral plus tricuspid annuloplasty group (10); 75.2% +/- 22% (17 years) for the mitral replacement plus tricuspid annuloplasty group (58); and 92.6% +/- 7.0% (16 years) for the combined aortic and mitral valve surgery plus tricuspid annuloplasty group (21). Ninety-eight percent of the survivors were in New York Heart Association class I or II postoperatively. Of 21 randomly selected patients investigated by pulsed Doppler echocardiography, 14 (67%) had no regurgitation or grade 1/4 tricuspid regurgitation and the remaining seven (33%) had grade 2/4 regurgitation postoperatively. Our experiences suggest that bicuspidalization annuloplasty can be a reliable method in the vast majority of patients with functional tricuspid regurgitation.

Actuarial Analysis↗