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Biomedical subjects

K Kodama

Publications and source records attributed to K Kodama.

At least 577 records · Page 32Linked to original sources

Acute hemodynamic effects of a new inotropic agent, OPC-8212, on severe congestive heart failure.

The hemodynamic and clinical effects of OPC-8212, a newly synthesized, orally effective inotropic agent, were assessed for the first time in ten patients with severe congestive heart failure by means of right heart catheterization with a Swan-Ganz catheter. Cardiac output was determined by the thermodilution technique. Patients received a single oral dose of 6 mg/kg. To determine the magnitude and time-course of the effects of OPC-8212, measurements were made during an observation period before and 2, 4, 8, and 12 h after administration. Blood was also taken at these times for measurement of the concentration of plasma OPC-8212. No large meals were allowed during the first 4 h. After the single oral dose of OPC-8212, plasma concentrations increased rapidly, reaching an effective level after 8 h and peaking at 12 h. Hemodynamic performance improved as the mean OPC-8212 plasma level increased, with the maximum effect being observed between 8 and 12 h after acute administration of the drug. At 8 h, the cardiac index was increased from the baseline value of 2.4 +/- 0.2 (SEM) to 2.8 +/- 0.3 1/min/m2 (P less than 0.01). The stroke work index rose from 26.2 +/- 5.1 to 31.7 +/- 60 g . m/m2. The excessive pulmonary artery diastolic pressure fell from 22 +/- 2 to 17 +/- 3 mmHg at 8 h (P less than 0.001) and to 16 +/- 2 mmHg (P less than 0.001) at 12 h. The incidence of ventricular premature beats was not increased and no other side effects were observed.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Oral↗

Male siblings with Takayasu's arteritis suggest genetic etiology.

Takayasu's arteritis is a nonspecific arteritis involving the aorta and its major branches. The disease mainly affects young females and familial incidence is uncommon. In this paper, two rare cases of male siblings with Takayasu's arteritis and the results of their HLA typing are described. The HLA haplotype of the two cases was completely identical--A2-B40-Cwl and A24(9)-Bw59-Cwl, DR2, and DR4. It is reported that Bw52(5) is strongly associated with the disease. However, in our cases, Bw52(5) was not found, while DR2 and DR4, which have been reported in association with several autoimmune disease, were detected. Accordingly, in these cases, genetic factors might be associated with the pathogenesis of the disease through an autoimmune mechanism.

Aortic Arch Syndromes↗

Oral OPC-8212 for the treatment of congestive heart failure: hemodynamic improvement and increased exercise capacity.

The chronic effects of the oral administration of OPC-8212 (3,4-dihydro-6-[4-(3,4-dimethoxybenzoyl)-1-piperazinyl]-2(1H)-quinolinon e) on resting hemodynamics and exercise capacity were assessed in 15 patients with congestive heart failure (NYHA II-IV). Doses of 30 or 60 mg per day were given per os over 3.0 weeks on average (range 2-6 weeks). Multigated radionuclide ventriculography and multistage exercise testing were performed before and during OPC-8212 therapy to assess the changes in left ventricular volume and exercise capacity respectively. Systolic blood pressure showed a slight increase (from 123 +/- 3 to 129 +/- 4 mmHg) during OPC-8212 therapy, while heart rate was unchanged (69 +/- 3 vs 67 +/- 3 beats/min). The left ventricular end-diastolic volume index decreased from 127 +/- 9 to 107 +/- 7 ml/m2, and ejection fraction and the P/V index (the ratio of peak systolic pressure to left ventricular end-systolic volume index) increased during OPC-8212 therapy (from 27% +/- 3% to 30% +/- 4% and from 1.5 +/- 0.2 to 2.0 +/- 0.3 mmHg/ml/m2 respectively). NYHA functional class was improved in 9 of 15 patients, and the average peak work load achieved during exercise testing increased from 27 +/- 6 to 47 +/- 7 W. No significant adverse effect was observed in any patient. These results indicate that OPC-8212 enhances the inotropic state and, hence, reduces heart size with no change in heart rate. Moreover, it increases exercise capacity. Thus, OPC-8212 is an inotropic agent with promise for application in the long-term treatment of congestive heart failure.

Administration, Oral↗

Clinical assessment of elastic properties of large coronary arteries: pressure-diameter relationship and dynamic incremental elastic modulus.

Vascular elastic properties in vivo (dynamic incremental elastic modulus [Ep(dyn)]) of large coronary arteries were assessed from the pressure-diameter relationships of the large coronary arteries in 46 patients with suspected ischemic heart disease. Ep(dyn) represents the vascular stiffness primarily determined by the organic sclerotic changes of the vascular wall and the vascular smooth muscle tone. Coronary arterial diameter was obtained from the magnified cine coronary arteriograms by using a computerized caliber measurement technique. The mean Ep(dyn) of the left main coronary artery and the proximal portions of the left anterior descending and circumflex coronary arteries with apparently normal angiograms were significantly (P less than 0.01) increased as the number of involved coronary vessels was increased. Mean Ep(dyn) values in multi-vessel disease were comparable with those of dilated segment by the percutaneous transluminal coronary angioplasty, indicating that the vascular sclerotic changes are not localized to the narrowed segments but diffusely distributed to the angiographically normal vascular wall. In 4 patients who had successful percutaneous transluminal coronary angioplasty, Ep(dyn) of the dilated coronary segment showed markedly higher values (0.21-0.30 X 10(6) Nm-2) than the normal values (0.16 +/- 0.06 X 10(6) Nm-2 in left anterior descending coronary artery). In contrast, there was no significant difference in Ep(dyn) values of the angiographically normal left main coronary trunk, proximal portions of left anterior descending and circumflex arteries between patients with and without vasospastic angina. During myocardial ischemia induced by ergonovine maleate, vasospastic response of the non-diseased segment was comparable with that in patients who did not have an anginal attack during the ergonovine test. Thus, in contrast to the sclerotic change, abnormal vasoconstrictive property of the coronary artery may be localized to the diseased segment.

Adult↗

Extensive sequence homology of the goldfish ras gene to mammalian ras genes.

We cloned ras-related sequences from goldfish genomic libraries constructed as recombinants using the lambda phage. Restriction enzyme mapping of the clones obtained revealed three kinds of ras-related sequences among approximately 350,000 genomic clones. One of these clones was partially sequenced. Comparison with the nucleotide sequences of mammalian ras genes showed that the determined sequences covered the predicted amino acid coding regions and parts of the intervening regions. The predicted amino acid sequences of the cloned ras-related goldfish gene suggested that the coding region is localized separately in DNA, and that its exon-intron boundaries are exactly the same as those of corresponding mammalian genes. The nucleotide and amino acid sequences of the goldfish ras-related gene may have extensive homologies to mammalian p 21 protein. Among the three mammalian ras proteins, the predicted amino acid sequence of the sequenced ras-related goldfish clone is most closely homologous (96%) to the Kirsten ras protein. Differences in the predicted amino acid sequence were greatest in the sequence predicted from the fourth exon; fewer differences were found in the sequence from the third exon, and only slight or no differences were found in the sequence predicted for the first and second exons. The 12th and 61st amino acids from the N-terminal of the protein, which are thought to be critical positions for GTP binding and catalysis, are both conserved in the goldfish protein.(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acid Sequence↗

Life events related to the inception of anxiety neurosis.

We collected the data of life events contributing to the onset of anxiety states in our series of 118 patients with anxiety neurosis by using a check list specially designed for the purpose. We found that the most significant events producing anxiety states were those concerning "illness and medical treatment" in both sexes. From these data, a suggestion was made that stressful life events directly menacing "the security of life" played the most important role in the inception of anxiety neurosis.

Adolescent↗

Noninvasive evaluation of aortic regurgitation by continuous-wave Doppler echocardiography.

Continuous-wave Doppler echocardiography was used to examine the aortic regurgitant flow velocity pattern in 32 patients with aortic regurgitation (AR) and 10 patients without AR. The aortic regurgitant flow velocity patterns, characterized by a rapid rise in flow velocity immediately after closure of the aortic valve, high peak flow velocity, and a gradual deceleration until the next aortic valve opening, were successfully obtained in 30 of the 32 patients with AR (sensitivity 94%, specificity 100%). The velocity decline was greater in patients with severe AR; thus, the slope of the velocity decline (deceleration) and the time to decline to half the peak velocity (half-time index) were measured from the flow velocity pattern. The deceleration became greater and the half-time index shortened in accordance with angiographic grading of AR (p less than .01). The deceleration and the half-time index also correlated well with the aortic regurgitant fraction (r = .79, p less than .01; r = -.89, p less than .01). Because the half-time index could be measured easily and independently of Doppler incident angle, it seemed a simple and accurate index of assessing the severity of AR. Thus continuous-wave Doppler echocardiography permitted the noninvasive evaluation of AR.

Adult↗

Continuous-wave Doppler echocardiographic detection of pulmonary regurgitation and its application to noninvasive estimation of pulmonary artery pressure.

Continuous-wave Doppler echocardiography was used to estimate pulmonary artery pressures by measuring pulmonary regurgitant flow velocity in 21 patients with pulmonary hypertension (mean pulmonary artery pressure greater than or equal to 20 mm Hg) and 24 patients without pulmonary hypertension. The pulmonary regurgitant flow velocity patterns, characterized by a rapid rise in flow velocity immediately after closure of the pulmonary valve and a gradual deceleration until the next pulmonary valve opening, were successfully obtained in 18 of the 21 patients with pulmonary hypertension and in 13 of the 24 patients without pulmonary hypertension. As pulmonary artery pressure increased, pulmonary regurgitant flow velocity became higher; the pulmonary artery-to-right ventricular pressure gradient in diastole (PG) was estimated from the pulmonary regurgitant flow velocity (V) by means of the simplified Bernoulli equation (PG = 4V2). The Doppler-determined pressure gradient at end-diastole correlated well with the catheter measurement of the pressure gradient at end-diastole (r = .94, SEE = 3 mm Hg) and with pulmonary artery end-diastolic pressure (r = .92, SEE = 4 mm Hg). The peak of Doppler-determined pressure gradient during diastole correlated well with mean pulmonary artery pressure (r = .92, SEE = 5 mm Hg). Thus continuous-wave Doppler echocardiography was useful for noninvasive estimation of pulmonary artery pressures.

Adolescent↗

Beneficial effects of atrioventricular sequential pacing on cardiac output and left ventricular filling assessed with pulsed Doppler echocardiography.

There has been increased interest in the beneficial effects of atrio-ventricular (AV) pacing over ventricular (V) pacing. This study attempted to evaluate the changes in cardiac output and left ventricular filling dynamics when the pacing mode was switched from V pacing to AV pacing. Study population consisted of 26 patients with multiprogrammable AV pacemakers. Cardiac output was determined as a product of echocardiographically determined cross sectional area of the aortic annulus and Doppler-determined velocity integral of left ventricular outflow over systole. Left ventricular peak rapid filling rate (PFR) and peak atrial filling velocity to peak rapid filling velocity ratio (A/R) were determined from measurements at the mitral annulus. Cardiac output showed a significant improvement when the pacing mode was switched from V to AV pacing, and the percent change ranged from 3 to 73% (average 26%). The improvement in cardiac output brought about by AV synchrony was greater in patients with smaller PFR (r = -0.71, p less than 0.01) and larger A/R ratio (r = 0.77, p less than 0.01). On the other hand, PFR was greater with V pacing than with AV pacing. Greater increment of the PFR was produced by the loss of atrial contraction in patients with smaller PFR (r = -0.82, p less than 0.01) and larger A/R ratio (r = 0.76, p less than 0.01). Thus, AV pacing provides a great improvement in left ventricular filling, i.e., cardiac output, which cannot be obtained with V pacing even with the compensatory enhancement of left ventricular rapid filling. These beneficial effects of AV pacing seemed to be greater in patients with impaired left ventricular rapid filling.

Adolescent↗

Relationship between hyperinsulinemia and risk factors of atherosclerosis.

In order to study the relationship between hyperinsulinemia and atherosclerosis, an examination was made on the relationship of hyperinsulinemia to the risk factors of atherosclerosis, using as subjects a total of 2,927 composed of Japanese resident in Hawaii and Los Angeles and Japanese resident in Hiroshima whose age ranged from 40 to 79 and who underwent oral glucose tolerance test in our Hawaii-Los Angeles-Hiroshima medical study between 1978 and 1982. The subjects were classified into five groups of comparable size according to fasting insulin level, studied on the various risk factors of atherosclerosis in each group. The results of this study showed that the hyperinsulinemia group had in comparison with the four other groups a higher mean body mass index, mean serum total cholesterol value and mean serum triglyceride value, and further had a higher prevalence of hypertension, diabetes mellitus, ECG abnormalities, hypercholesterolemia and hypertriglyceridemia. Moreover, the mean serum HDL-cholesterol value was lower in the hyperinsulinemia group than in the other four groups. A similar examination was made with subgroups with normal body weight, and almost the same results were obtained. The above results suggest that hyperinsulinemia is rather strongly implicated in the development of atherosclerosis via a number of relationships though not specifically indicating that hyperinsulinemia independently is a risk factor of atherosclerosis.

Adult↗

The effects of intravenous infusion of solutions with different colloid osmotic pressures on rat mesenteric lymph pressure.

The effects of intravenous infusion of solutions of varied colloid osmotic pressure on mesenteric lymph pressure were measured by a glass micropipette. The lymph pressure was 4.0 +/- 1.6 cm H2O between the second and third valve of rat mesenteric lymphatic vessels with diameter of 101 +/- 25 micron (mean +/- SD). Intravenous infusion of 1 ml/100g body weight (B.W.) of isotonic saline, 5% glucose solution, and 20% glucose solution increased the lymph pressure by 1.6 +/- 0.5 cm H2O, 1.5 +/- 0.3 cm H2O and 2.0 +/- 1.0 cm H2O, respectively. Infusion of 2 ml/100g B.W. of the same solutions increased the lymph pressure by 3.3 +/- 1.3 cm H2O, 3.3 +/- 1.6 cm H2O and 3.7 +/- 0.8 cm H2O, respectively. Infusion of hydroxyethyl starch solution, with colloid osmotic pressure of 25 mmHg, minimally altered the lymph pressure. One ml/100g B.W. infusion of low molecular weight dextran solution, with colloid osmotic pressure of 162 mmHg, decreased the lymph pressure by 1.3 +/- 0.9 cm H2O, and 2 ml/100g B.W. infusion of this solution decreased the lymph pressure by 2.0 +/- 1.0 cm H2O. The different effects on lymph pressure derive from the differences in colloid osmotic pressure of these solutions in conformity with the Starling hypothesis.

Animals↗

Stable integration of woodchuck hepatitis virus DNA in transplanted tumors and established tissue culture cells derived from a woodchuck primary hepatocellular carcinoma.

The fate of integrated woodchuck hepatitis viral (WHV) DNA was systematically investigated in DNA samples from primary hepatocellular carcinoma (HCC) of woodchucks, solid tumors transplanted in athymic mice derived from a primary HCC of woodchuck, and an established cell line of tissue culture originating from the transplanted tumor. In four of five woodchuck primary HCCs, WHV DNA integration was demonstrated in addition to various amounts of extrachromosomal replicative intermediate WHV DNA. The integration pattern of the primary HCCs does not indicate a common integration site on the host chromosome. The integration pattern in the established cells is identical to that in the transplanted tumor and similar but slightly different from that of the primary HCC. No extrachromosomal or replicative intermediates of WHV DNA were detected in the transplanted tumors or in the established cells of tissue culture. There are three integration sites on the chromosomes of the established cells. Results of Southern hybridization and restriction maps of cloned fragments suggest that all of these integrated WHV DNA sequences are not a complete genome but a part of the genome. A small portion corresponding to the cohesive region of the genome was not detected in all of these integrated WHV DNA. A positive role of WHV DNA integration on the generation of HCC is strongly suggested by the high incidence of WHV DNA integration in woodchuck primary HCCs and the stable maintenance of a certain mode of WHV DNA integration in the hepatoma-derived cell populations during passages of transplantation or serial growth of tissue culture.

Animals↗