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Biomedical subjects

T Ota

Publications and source records attributed to T Ota.

At least 235 records · Page 13Linked to original sources
PubMed1992

Effect of intra-aortic balloon pumping after cardiac surgery: comparative study of use in coronary bypass and valve replacement.

To compare the effects of intra-aortic balloon pumping (IABP) between use for coronary artery bypass grafting (CABG) and for valve replacement, the results were reviewed in 513 patients who underwent CABG (n = 215) or valve replacement (n = 298). The rate of weaning from IABP and in-hospital survival after IABP support were excellent in CABG patients, where all 21 CABG patients (100%) and 17 out of 25 valve replacement patients (68%) could be weaned from IABP, and 19 out of 21 CABG patients (90%) and 14 out of 25 valve replacement patients (56%) survived for a long period. From comparative studies of pre- and postoperative data, the duration of IABP support in patients who could be weaned from IABP or who achieved in-hospital survival tended to be more prolonged in patients with valve replacement than in those with CABG. Among patients having IABP postoperatively, 4 CABG patients and 8 valve replacement patients had definite indications for IABP support. In the other 34 patients, preoperatively depressed cardiac function was observed in 12 patients where most of them were patients with valve replacement. Postoperative improvements in cardiac index were not as marked in patients undergoing valve replacement with IABP. The outcome for patients who had definite causes of post-operative cardiac failure, which were more numerous in the valve replacement group, was poor even if they could be weaned from much longer IABP support. In conclusion, the IABP was more effective in patients with CABG compared with those with valve replacement, because the number of patients who had a depressed cardiac function during the pre- and postoperative periods was lower in the CABG group and the incidence of serious perioperative complications was less frequent in these patients.

Adult↗
PubMed1992

[Echocardiographic assessment for surgical treatment in patients with aortic stenosis].

The diagnostic value of preoperative echocardiography was assessed in 51 patients with aortic stenosis. We measured 1) left ventricular-aortic pressure gradient (LV-Ao PG), 2) aortic valve area (AVA), 3) grade of LV hypertrophy and function, and 4) aortic annulus diameter for determining the availability and size of a prosthesis. The maximal instantaneous PG (max-PG) by continuous-wave (cw) Doppler echocardiography correlated well with the peak-to-peak PG by cardiac catheterization (cath), and their correlation equation was y = 1.49 x -48.3 with a correlation coefficient of 0.90. Excellent correlations were also found between cw-max PG and cath-max PG (r = 0.84), and between cw-mean systolic PG and cath-mean systolic PG (r = 0.80). The AVA of the echocardiogram, which was derived from the stroke volume using Gibson's M-mode echocardiographic formula and the cw-Doppler echocardiographic mean gradient, correlated well with the AVA of the cardiac catheterization using Gorlin's formula (y = 1.33 x -0.61, r = 0.79). Preoperative LV pump function, which was obtained from the M-mode echocardiogram, correlated inversely with end-systolic wall stress, and a depressed LV pump function was observed in patients with inadequate hypertrophy. In such patients, however, depressed function was alleviated after surgical treatment. Thus, we considered that cardiac catheterization for further examination is unnecessary, even in such patients. To determine the available size of the prosthesis, measurement of the inner diameter of the aortic annulus on the long-axis cross-sections was the most useful.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

[Clinical and hemodynamic sequelae of mitral prostheses evaluated by Doppler echocardiography].

To determine the relative superiority of a prosthesis in the mitral position, in vivo hemodynamics were examined by Doppler echocardiography, and the results were compared with other types of mechanical mitral valves including 63 Björk-Shiley convexo-concave (BS) values, 30 Duromedics (DM) valves, and 58 Medtronic Hall (MH) valves. For this comparison, the following indices were evaluated: peak velocity of mitral flow (PV), mitral valve orifice area (MVA), mitral valvular regurgitation, New York Heart Association (NYHA) classification, pulmonary capillary wedge pressure (PC), cardiac index (CI) and valve-related complications. On Doppler echocardiograms, PV ranged from 1.2 to 2.0 m/sec with a mean of 1.6 m/sec. There was no evident relationship between the PV and the valve size in each type of prosthesis, and no significant difference in the PVs among the valves. The mean MVA was 2.6 cm2 (25 mm DM, 25 mm MH), which was regarded satisfactory from a clinical standpoint. MVA increased with the increase in the valve size in all types of valves, and of all sizes, MVA was larger in the DM and MH groups than in the BS group. Similarly, the incidence of valvular regurgitation was relatively low in all groups, and the degree of regurgitation proved to be grade II or less in all cases. As for the clinical results, clinical symptoms (NYHA) and hemodynamic states (PC, CI) improved postoperatively, with the differences among the types of prosthetic valves being insignificant. The incidences of thromboembolism, valvular thrombosis, valve failure and prosthetic endocarditis were relatively low in all groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Flow Velocity↗
PubMed1992

[Clinical significance of rheumatoid factor--its complement activating property and isotype].

We investigated the relationship between complement-activating properties of rheumatoid factors (RF) and their isotypes. Active and inactive RA patients without extra-articular symptoms (EAS) and those with EAS were studied. Patients with SLE, liver cirrhosis (LC) and normal volunteers were served as controls. Isotype of RF was measured by ELISA and complement activation (CA) of RF was measured by hemolytic assay. The CA values were significantly higher in RA patients with EAS than those in RA patients without EAS and with other diseases. The IgG and IgM-RF values were significantly higher in active RA without EAS than in inactive RA. Positive correlations between IgM-RF values and CA values were observed in RA with or without EAS, SLE and LC. The Sephadex G-200 gel filtration analysis of sera revealed CA in only 19S IgM fraction. Additionally, we purified 19S IgM-RF from sera of RA, SLE and LC patients by affinity chromatography, and found 19S IgM-RF had CA. These data suggest that serum IgM-RF may play a critical role in the pathogenesis of RA, especially in RA with EAS.

Arthritis, Rheumatoid↗
PubMed1992

Effect and limitation of intra-aortic balloon pumping following valve replacement surgery.

To evaluate the effect and the limitation of intra-aortic balloon pumping (IABP) in patients with severe left ventricular failure (LVF) following valve replacement surgery, we assessed the results of 282 patients who underwent such surgery. Among 25 patients in whom IABP was used after valve replacement, 17 patients could be weaned from IABP, and 14 of them achieved long-term survival. The durations of IABP support for patients who were weaned from IABP were shortened and were mostly within 48 hours, whereas those in patients not weaned from IABP tended to be prolonged. Among 25 IABP patients, 8 had definite causes of LVF such as perioperative myocardial infarction, but the other 17 patients experienced LVF despite uneventful operation. In the latter group of patients, preoperatively depressed left ventricular function was observed in 10 patients. In the former group of patients, the duration of IABP was much longer, and the weaning rate, as well as survival rate, was significantly poorer. On the other hand, in the latter-group patients, the duration of IABP was shortened and the survival rate was excellent. In conclusion, IABP support for patients with postoperative LVF of unknown causes, which might include patients with preoperatively depressed left ventricular function, was sufficiently effective, whereas no significant effect of IABP was noted for patients experiencing LVF after definite and serious perioperative complications.

Adult↗
PubMed1992

Preliminary criteria for classification of adult Still's disease.

We have attempted to design classification criteria for adult Still's disease by analyzing the data obtained through a multicenter survey of 90 Japanese patients with this disease and of 267 control patients. The proposed criteria consisted of fever, arthralgia, typical rash, and leukocytosis as major, and sore throat, lymphadenopathy and/or splenomegaly, liver dysfunction, and the absence of rheumatoid factor and antinuclear antibody as minor criteria. Requiring 5 or more criteria including 2 or more major criteria yielded 96.2% sensitivity and 92.1% specificity. However, an exclusion process will be needed for an accurate classification, since this disease is relatively rare.

Adolescent↗
PubMed1992

[A case of dermatomyositis associated with thymic abnormalities].

A case of dermatomyositis (DM) associated with thymic cyst with lymphoid follicle formations has been reported. A 57-year-old man developed polyarthralgia, muscle weakness, heliotrope rash and Gottron's sign. Laboratory findings showed elevated values of creatine-phosphokinase, aldolase and transaminase. He was diagnosed as DM and was treated with prednisolone 50 mg/day. Muscle weakness was improved immediately, although rash persisted unchangeably. He was examined for coexistence of malignant tumor which had been reported frequently as associated with DM. Enlargement of thymus was found by computer tomography and then thymectomy was performed. In his thymus, lymphoid follicle formations, which are as often encountered in other autoimmune diseases, were found. So far, the beneficial effect of thymectomy on the improvement of immunological abnormalities not only in patients with myasthenia gravis but also in patients with other autoimmune diseases has been recognized. In this case, intractable rash in DM improved after thymectomy. Further study needs to clarify the relationships between DM and thymic abnormalities.

Dermatomyositis↗
PubMed1991

A Waldenström's macroglobulin with anti-G3m(b1) antibody activity.

A human monoclonal macroglobulin (IgM, K) from a patient (KI) with Waldenström's macroglobulinemia was shown to have antibody activity against a human IgG (Gm) allotype. In hemagglutination tests, only one anti-D serum with G3m(b0b1) reacted with macroglobulin KI. Antiglobulin specificity of macroglobulin KI was determined to be an anti-G3m(b1) antibody by hemagglutination inhibition tests. Fab fragments from macroglobulin KI could react with human IgG3 protein possessing G3m(b1), but Fc fragments could not react. Gm phenotype in IgG isolated from serum KI was determined to be Gm(a,z,g,b0,s,t,u). This is the first report of a Waldenström's macroglobulin with antiglobulin specificity against a Gm allotype.

Aged↗
PubMed1991

Mechanism of action of ginsenoside Rh2: uptake and metabolism of ginsenoside Rh2 by cultured B16 melanoma cells.

The uptake and metabolism of ginsenoside Rh2 (Rh2) by B16 melanoma cells were studied. In a medium containing 2% fetal calf serum, the uptake of Rh2 reached a maximum of 3 nmol/10(6) cells at 3-6 h after Rh2 (12.5 microM) was added, but gradually decreased to 0.8 nmol/10(6) cells. In these cells, protopanaxadiol (PPD), which is an aglycon of Rh2, increased inversely with the decrease in Rh2 as a result of deglycosylation by the cells. When PPD (8 microM) was added to the medium, the uptake reached a plateau of 2.4 nmol/10(6) cells, within 0.5 h. The association constant of Rh2 (1.74 +/- 1.08 x 10(6) M-1) for bovine serum albumin (BSA) was significantly higher than that of PPD (9.90 +/- 1.10 x 10(4) M-1). In a serum-free medium, both Rh2 and PPD were incorporated within 1.5 h. The uptake rate constant of Rh2 (1.20 +/- 0.20 h-1) was not significantly different from that of PPD (1.02 +/- 0.15 h-1), but the release rate constant of PPD (2.12 +/- 0.38 h-1) was significantly lower than that of Rh2 (3.03 +/- 0.57 h-1). These differences in affinity for BSA and the release rate constants were thought to be the cause of the difference in uptake kinetics between these drugs. The effects of Rh2 and PPD on the cells were identical, and there was no difference in the lag periods before the appearance of their effects, despite their differing rates of uptake.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1991

B-B cell interactions in the spontaneous activation of B cells in autoimmune NZB mice.

We analyzed the mechanism of spontaneous B cell activation in lupus mice by using anticlass-II antibody in vitro. The in vitro culture of B cells from old NZB mice markedly produced Ig without any stimulation, while B cells from NZW mice did not. The addition of anticlass-II antibody (anti-Iad antibody) to the culture inhibited Ig production of NZB B cells in a concentration-dependent manner. On the other hand, the addition of anticlass-I antibody (anti-H-2Dd antibody) and anticlass-II antibody with different specificity (anti-Iak) gave no effect on the Ig production of NZB B cells. When mitomycin C-treated B cells were added to in vitro culture of responder B cells as a stimulator, Ig production of responder B cells was enhanced in a concentration-dependent manner. However, the enhancing effect of the stimulator B cells was abrogated by the pretreatment with anticlass-II antibody. The stimulator B-cell activity to NZB B cells was marked in NZB B cells, moderate in NZB/W F1 B cells, and weak in NZW B cells. Furthermore, the stimulator B-cell activity with regard to NZB B cells was marked in old female NZB B cells, moderate in old male NZB B cells, and weak in young NZB B cells. The expression of class II antigens on the surface of old female NZB B cells was significantly higher than that of old male NZB and young NZB B cells. These results suggest that in lupus mice the spontaneous B-cell activation is induced by an abnormal B-B cell interaction mediated by class II antigens.

Animals↗
PubMed1991

Suppressive effect of hyperbaric oxygenation on immune responses of normal and autoimmune mice.

We studied the effect of hyperbaric oxygenation (HBO) on immune responses in normal and autoimmune mice. Mice were exposed to HBO in an animal chamber at a pressure of 252.5 kPa for 1 h and once a day for 5 days. The immunization of C3H/He mice with sheep erythrocytes induced marked anti-sheep erythrocyte antibody response on day 7. However, this response was markedly suppressed in HBO-treated mice. The suppression is dependent on the duration of HBO and it works on the early and the late stage of antibody responses. HBO suppresses the development of both sheep erythrocyte-specific B cells and helper T cells after the immunization. Then, we tried to expose autoimmune mice to HBO. Spontaneous immunoglobulin production of NZB and MRL/lpr spleen cells was also significantly suppressed by HBO. Furthermore, long term HBO exposure results in the suppression of the development of autoimmune symptoms such as proteinuria, facial erythema and lymphadenopathy in MRL/lpr mice. All these results suggest that HBO is applicable for the treatment of autoimmune diseases.

Animals↗
PubMed1991

Binding position of azathioprine with bovine serum albumin determined by measuring nuclear magnetic resonance relaxation time.

The interaction between azathioprine (AZ) and bovine serum albumin (BSA) is mainly due to hydrophobic binding according to the dependence of the binding constant on the ionic strength obtained by equilibrium dialysis. The binding constant and partition coefficient of AZ were smaller than those of warfarin, phenylbutazone and ibuprofen. Little variation in the proton chemical shift of AZ was observed whether there was an absence or presence of BSA (7.25 x 10(-5) M). The spin-lattice relaxation time (T1) of AZ decreased in the presence of BSA to 6-22%. The spin-spin relaxation rate (1/T2) of AZ increased 16-24 times for the methyl group and the imidazole ring and 8-13 times for the purine ring in the presence of BSA. The ratio of the spin-spin relaxation rate of the free AZ to the bound AZ ((1/T2)b/(1/T2)f) of the methyl group and the imidazole ring was 2-3 times larger than that of the purine ring. The binding of AZ to BSA was concluded to be mainly at the methyl group on the imidazole ring of AZ.

Animals↗
PubMed1991

[Left ventricular failure following valve replacement surgery in patients with mitral stenosis--its genesis, prognosis, and the method for the preoperative prediction].

To detect the genesis and the prognosis of left ventricular failure (LVF) following the valve replacement surgery to mitral stenosis (MS), preoperative values and postoperative courses were assessed in 90 patients with MS. The criteria for LVF were as follows: postoperative severe left ventricular (LV) dysfunction which required intra-aortic balloon pumping (IABP) support with large doses of catecholamine. Among these 90 patients, LVF had occurred in 13 patients, of which 6 had a definite cause of LVF (group A), but the other 7 patients failed to LVF despite uneventful operation (group B). Comparing the pre- and postoperative values in these two groups, the duration of IABP support was much longer in group A, and the weaning rate from IABP was also poor in this group. Long-term survival was achieved only by one patient in group A, whereas 5 out of 6 patients of group B survived long-term postoperatively. Evaluating the preoperative LV function in group B patients, depressed LV function [%fractional shortening (%FS) less than or equal to 27%] was observed in 5 patients. Among these 5 patients, three had low cardiac output; in other two, preoperative %FS was severely depressed. In such patients, the responses to preoperative dobutamine administration tests were poor, and the values of %fibrosis of the LV myocardium, which was demonstrated by intraoperative biopsy, was greater in them. In conclusion, the causes of postoperative LVF following the mitral valve replacement to MS was divided into two categories: one due to perioperative complication and another due to preoperatively impaired LV function.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

[A case of successful treatment of aneurysms of the suture line following Bentall's operation].

A 33-year-old male who had received Bentall's operation 10 years ago was admitted to our hospital with severe chest pain. The pseudoaneurysm at the right coronary ostium was observed on angiography and CT scan. He underwent the repair of the anastomosis between the graft and the right coronary ostium under extracorporeal circulation. Although he was discharged from the hospital asymptomatically, he was again admitted to our hospital with severe chest pain and back pain 4 months after re-operation. Aneurysmal formation of the ascending aorta due to blood leakage from the distal anastomotic suture line was observed and the graft was compressed by hematoma on angiography and CT scan. He underwent re-operation of the distal anastomosis of the graft, and could be discharged from the hospital uneventfully.

Adult↗
PubMed1991

[Surgical treatment for the association of cardiovascular disease and cholelithiasis].

Six cases of the association of cardiovascular disease and cholelithiasis were treated in our surgical ward. Simultaneous operation was carried out for four of them, and two-stage operation was performed in the remaining two cases. As the time of the simultaneous operation, reconstruction of the abdominal aorta and cardiac surgery was firstly done, and cholecystectomy was secondly performed after closing the retroperitoneum or the median sternotomy. All of these cases were discharged from hospital uneventful. In conclusion, cholecystectomy could be safely performed at the same time of the aortic reconstruction and cardiac surgery without any high risk for the patients.

Adult↗