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Biomedical subjects

Y Koga

Publications and source records attributed to Y Koga.

At least 505 records · Page 28Linked to original sources
PubMed1986

Comparable effects of oral diltiazem and verapamil in the treatment of hypertrophic cardiomyopathy. Double-blind crossover study.

The effects of oral diltiazem, 180 mg/day, were compared with those of oral verapamil, 240 mg/day, in 32 patients with hypertrophic cardiomyopathy (HCM), using a double-blind crossover study design. In the first treatment period, diltiazem and verapamil improved subjective complaints in 83% and 71% of those who were symptomatic in the baseline period. Maximal oxygen consumption on exercise stress test increased with verapamil by 2.9 +/- 4.2 ml/Kg/min (p less than 0.05), and tended to increase with diltiazem. Verapamil also reduced the amplitude of negative T wave. In the statistical analysis based on the crossover design, diltiazem and verapamil did not differ in global improvement, overall safety and global utility ratings. In addition, both drugs showed comparable effects on electrocardiographic and echocardiographic variables and exercise tolerance except for minor differences in diastolic blood pressure, T wave amplitude and peak exercise heart rate. On the other hand, verapamil tended to induce more serious side effects, forcing the discontinuation of medication in 3 patients. Therefore, the present study indicates that diltiazem is essentially equally as effective as verapamil and is preferable in the treatment of patients with HCM since it may exhibit fewer serious side effects.

Administration, Oral↗
PubMed1986

Production kinetics and immunochemical properties of carcinoembryonic antigen and nonspecific cross-reacting antigen synthesized by various human tumor cell lines.

The production kinetics and immunochemical properties of carcinoembryonic antigen (CEA) and nonspecific cross-reacting antigen (NCA) in various human tumor cell lines were studied. By radioimmunoassay (RIA), five CEA-producing tumor cell lines tested--2 derived from colonic (M7609 and CCK-81), one from pancreatic (QGP-1) and 2 from lung (HLC-1 and KNS-62) carcinomas--were found to produce NCA simultaneously. The cellular contents of CEA and NCA and the amounts of both antigens released into the culture medium were highly variable among the cell lines. It was a distinct contrast that one cell line (CCK-81) released very large amounts of CEA and NCA into the medium while having the smallest amounts of both antigens in the cells, whereas the others contained much larger amounts of the antigens in the cells as compared with the amounts released into the medium. For most of the cell lines, the production of both CEA and NCA increased in the stationary phase of growth as compared with the exponential phase. The production kinetics of both CEA and NCA appeared to be parallel with each other in all the cell lines, though the amount ratio of CEA to NCA produced was variable. By means of a double immunodiffusion test with polyclonal antibodies, antigenic uniformity with no unique organ-specificity was confirmed for all the CEA preparations from spent media of the cell lines, though some differences in the sugar moiety of CEA were detected by RIA using monoclonal antibodies. No antigenic differences among NCA preparations were observed. Upon sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), molecular heterogeneity was observed among CEA or NCA preparations isolated from cell lysates.

Animals↗
PubMed1986

Genetic background of high incidence of spontaneous tumors in BDX rats.

Genetic background of high incidence of spontaneous tumors in BDX rats was investigated with respect to susceptibility to physical or chemical agents and immune response. Percentages of colony forming ability of normal embryo fibroblasts from BDX rats after exposure to various doses of ultraviolet (UV) light, X-rays and Mitomycin C were almost identical to those of cells from control F344 rats. Furthermore, BDX rats showed similar level of rosette forming cells, blastogenic response, and plaque forming cell (PFC) response as compared with WKA rats used as a control, although BDX rats showed higher natural killer (NK) cell activity. These results indicate that high incidence of spontaneous tumors in BDX rats is not due to some defects in DNA repair or immune response. In 3 methylcholanthrene (MCA) carcinogenesis, however, BDX rats developed tumors very early; the mean latency periods for development of MCA-induced tumors were 135 days in BDX rats and 256 days in F344 rats. Measurement of the inducibility of specific aryl hydrocarbon hydroxylase (AHH) activity in liver microsomes revealed that BDX rats showed higher inducibility than F344 rats: the inducibilities were 23.7 in BDX rats and 5.7 in F344 rats. Higher inducibility of AHH in BDX rats seemed to be parallel to earlier development of tumors in MCA-carcinogenesis in the rats. Thus, it is most likely that high incidence of spontaneous tumors in BDX rats is due to high susceptibility to some chemical carcinogens which may be contained in foods or drinking water in a small dose.

Animals↗
PubMed1986

[The result of the author's screening system of scoliosis in elementary and junior-high schools].

Since 1978 school screening of scoliosis has been performed every year by the system established by the author consisting of 4 step examinations in Niigata City. The initial examination is carried out with forward bending test associated with swing maneuver by school nurses or school doctors in all school boys and girls from the 4th grade of elementary school to the 3rd grade of junior-high school. The incidence of scoliosis with deformity of more than 20 degrees has been nearly constant ranging from 0.06% to 0.09% in elementary school, and 0.35% to 0.40% in junior-high school. The author compared the number and treatment of the patients of Niigata City seen in our scoliosis clinic in the period of 7 years before and after starting this program. After this program started, the number of the patients with scoliosis of more than 20 degrees has increased by 4 times. The number of surgery in adolescent idiopathic scoliosis, on the contrary, has markedly decreased.

Adolescent↗
PubMed1986

The quality of life is sustained after operation for carcinoma of the esophagus.

An interview was conducted to determine the quality of life, both objectively and subjectively, in 64 patients without a recurrence of the disease more than one year after esophageal resection and reconstruction with a gastric tube for carcinoma of the thoracic esophagus. Despite the decrease in body weight, the patients appeared to be well adjusted and had a most optimistic attitude toward their illness. The laboratory data showed normal values, postoperatively. As there was no evidence of a diminished quality of life in these patients, we consider that physicians should recommend surgical therapy for patients with carcinoma of the esophagus.

Aged↗
PubMed1986

[Left ventricular function in hypertrophic cardiomyopathy: a Tc-99m radionuclide angiographic study during exercise].

Hypertrophic cardiomyopathy (HCM) generally shows increased systolic function of the left ventricle at rest, although patients with HCM often have decreased exercise tolerance and develop dyspnea or chest pain. The present study was to investigate of left ventricular (LV) function during exercise in 26 patients with HCM using Tc-99m equilibrium angiocardiography, and to elucidate the mechanism of impaired functional reserve during exercise. Controls consisted of 11 normal volunteers and 12 patients with chest pain syndrome who had no abnormality on coronary arteriography or left ventriculography. In patients with HCM, LV ejection fraction decreased from 65 +/- 8 (mean +/- SD)% at rest to 59 +/- 18% at peak exercise, in contrast to an increase among controls (from 56 +/- 9% to 64 +/- 9%). As compared with resting values, cardiac output increased to 168 +/- 24% at peak exercise in HCM, but the increase was significantly less than that in controls (215 +/- 47%). Stroke volume decreased gradually to 83 +/- 16% during exercise in HCM, while it increased to 114 +/- 10% at an exercise level of half intensity, and it decreased slightly to 106 +/- 16% at peak exercise. LV end-systolic volume decreased among controls to 78 +/- 27% at peak exercise, but remained unchanged in HCM (118 +/- 58%). An increase in peak ejection rate at peak exercise was less in HCM than in controls (143 +/- 26% vs 170 +/- 42%). No significant differences were observed between the two groups concerning changes in indices of LV diastolic function including LV end-diastolic volume, peak filling rate or 1/3 filling rate during exercise. In the analysis of LV function curves, pulmonary arterial diastolic pressure increased to a greater extent in HCM than in controls (19 +/- 6 mmHg vs 11 +/- 6 mmHg); whereas, an increase in the stroke work index was less in HCM (80 +/- 26 g.m/m2/beat vs 121 +/- 21 g.m/m2/beat) at peak exercise. Thus, the LV function curve shifted downward and to the right in patients with HCM. The above findings indicate that LV functional reserve during exercise is impaired, especially as to systolic function in patients with HCM, while deterioration of diastolic function may be partly compromised by elevated filling pressure.

Cardiomyopathy, Hypertrophic↗
PubMed1986

[Ischemic colitis after surgery of abdominal aortic aneurysm].

Ischemic colitis following aortic reconstruction for abdominal aortic aneurysm was discussed. The low morbidity rate of postoperative abdominal symptom was recognized significantly when meandering mesenteric artery (MMA) was shown clearly in angiography before surgery. When inferior mesenteric artery (IMA) was patent before surgery, furthermore when IMA was not reconstructed, it is necessary for preventing postoperative ischemic colitis that mean IMA/systemic pressure ratio is above 0.5 or 0.6.

Aged↗
PubMed1986

Lymphocyte subsets in patients with dilated cardiomyopathy and perimyocarditis.

Lymphocyte subsets were analyzed in patients with DCM, arrhythmias following influenza symptoms and acute perimyocarditis, respectively by an automated laser flow cytometry system with the use of monoclonal antibodies. A lower percentage of OKT8+ cells and a high OKT4/OKT8 ratio were found in the DCM and arrhythmias groups. No phenotypic abnormalities in the lymphocyte subsets were found in patients with acute perimyocarditis who were favorably progressing in clinical features. The results suggest that an immunological disturbance thought to play a part of the pathogenesis of DCM or heart failure may cause the abnormality of lymphocyte subsets.

Adult↗
PubMed1986

[Factors related to the pathogenesis and clinicopathological findings in dilated cardiomyopathy].

It has been suggested that various factors related to dilated cardiomyopathy (DCM) may concern its onset and/or progression. This study was performed to clarify whether these factors contribute different clinical and morphological characteristics. Subjects were 39 patients with DCM, consisting of 28 men and 11 women whose average age was 46.5 years. The subjects were divided into five groups; namely, the Familial, Myocarditic, Alcoholic, Hypertensive, and Unknown Groups. Clinical parameters including past history, blood pressure, chest radiographs, electrocardiograms, echocardiograms and left ventricular end-diastolic pressures (LVEDP) were evaluated. Morphology of right ventricular endomyocardial biopsy specimens was evaluated in terms of hypertrophy, disarrangement, fibrosis, degeneration, endocardial thickening, interstitial changes, and types of fibrosis. The results were as follows: The Familial Group was characterized by the onset at younger age, highly elevated LVEDP, a lack of myocardial hypertrophy, and proliferation of small vessels. The Myocarditic Group was characterized by the onset at young age, elevated LVEDP, severe fibrosis showing a plexiform pattern in more than half of the patients, cellular disarrangement, and cellular infiltration. The Alcoholic Group showed possible improvement clinically and fatty infiltration in half of the patients. The Hypertensive Group was characterized by high prevalence of a previous alcohol intake, high diastolic blood pressure on admission, clinical improvement, and myocardial hypertrophy with a mild degree of perivascular fibrosis. From these findings, it is thought that each factor related to DCM offers a somewhat different clinical and histological profiles and that these factors may play an important role in the onset and/or progression of DCM. Furthermore, it is highly suggestive that specific therapy against these factors or the removal of these factors is especially necessary for favorable long-term prognosis of DCM.

Adolescent↗
PubMed1986

A diphytanyl ether analog of phosphatidylserine from a methanogenic bacterium, Methanobrevibacter arboriphilus.

Several ninhydrin-positive lipids were found in methanogenic bacteria and the structure of one of them, designated as PNL2 from Methanobrevibacter arboriphilus, was identified as a diphytanyl ether analog of phosphatidylserine. The chromatographic behavior of the lipid on thin-layer plates and on a DEAE-cellulose column was identical to the ester form of phosphatidylserine. The infrared spectra showed the presence of amino, carboxyl, ether, and phosphate groups, and the absence of an ester linkage. The hydrophobic portion of the lipid was identified as diphytanyl glycerol diether on the basis of the mass spectrum of the acetolysis product and gas-liquid chromatography of the iodinated alkyl chain prepared by hydroiodic acid cleavage of PNL2. The fast atom bombardment-ionization and field desorption mass spectrum provided a molecular weight of 819 and several fragment ions consistent with the proposed structure. Hydrofluoric acid hydrolysis resulted in water-soluble products including serine, phosphoserine, and ammonia, which accounted for 95% of hydrolyzed PNL2. The lipid product of the hydrolysis was mainly the diether form of phosphatidic acid. This is the first report on the structural characterization of an amino-containing phospholipid in archaebacteria. Amino lipids have been found in many other methanogenic bacteria.

Chromatography, Gas↗