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Biomedical subjects

K Katayama

Publications and source records attributed to K Katayama.

At least 469 records · Page 26Linked to original sources
PubMed1984

Clinical characteristics of left ventricular pressure decline during isovolumic relaxation in normal and diseased hearts.

To compare two expressions of the time constant for ventricular relaxation, 39 patients with various heart diseases (six normal, six angina pectoris [AP], 13 myocardial infarction [MI], eight hypertrophic cardiomyopathy [HCM], and six congestive cardiomyopathy [CCM]) were studied. One time constant was obtained by the method of Weiss et al. (T1) and the other was the ratio of left ventricular pressure at peak (-) dP/dt (Pm) to peak (-) dP/dt (T2). The deviation of T2 from T1 was expressed as 100 X (T2 - T1)/T1 (delta %). In normal subjects, T1 was nearly equal to T2 (32 +/- 3 and 32 +/- 6 msec, respectively), resulting in a low value of delta (-1 +/- 9). However, delta values in AP (20 +/- 23, p less than 0.05), MI (24 +/- 26, p less than 0.05), HCM (37 +/- 21, p less than 0.001), and CCM (46 +/- 24, p less than 0.001) were significantly higher than in normal subjects. Thus T1, T2, or delta separated the patient groups from the control subjects, and there were significant differences between T1 and T2 among the types of heart disease.

Adult↗
PubMed1984

Coronary angiography during exercise-induced angina with ECG changes.

Coronary angiography was performed at rest and during bicycle exercise immediately after the onset of angina and significant ST segment elevation or depression in the ECG. Of 11 patients, six showed significant reduction of coronary lumen diameter at the site of organic stenosis; mean values of stenosis (range) before and during exercise were 55% (25% to 88%) and 98% (89% to 100%), respectively. Five patients did not have any diameter change of the organic lesion; mean values of stenosis (range) before and during exercise were 84% (74% to 89%) and 84% (73% to 92%), respectively. Excluding the areas of these stenoses, diameters of left main coronary artery, proximal, middle, and distal left anterior descending, circumflex, and right coronary artery segments were measured before and during exercise. Diameter in each coronary artery segment during exercise was not significantly changed from that before exercise, both in the groups with and without diameter reduction. Exercise provoked a localized worsening of coronary artery stenosis without changing the diameter in the remaining artery. These findings suggest that the worsening of stenosis might be caused by a regional abnormality of the coronary artery that is not necessarily related to the degree of organic stenosis.

Adult↗
PubMed1984

Differentiation of endopeptidases and aminopeptidases by high-performance liquid chromatography of reaction products from chromogenic peptide p-nitroanilines as substrates.

A method for differentiating endopeptidases and aminopeptidases on the basis of substrate specificity is presented. Various synthetic chromogenic substrates, succinyl-(Ala)3-p-nitroaniline, succinyl-(Ala)2-p-nitroaniline, (Ala)3-p-nitroaniline, and (Ala)2-p-nitroaniline, were incubated with various peptidases and the incubation mixtures were directly analyzed by high-performance liquid chromatography to determine the splitting patterns of these substrates by the enzymes. The substrates and hydrolyzed products containing the chromophore were separated on a reverse-phase column under isocratic conditions, and the chromophore was specifically detected in the effluent fractions by absorbance measurement at 314 nm. Endopeptidases, leucine aminopeptidase, and dipeptidyl aminopeptidase showed different patterns of cleavage of the substrates. This simple and rapid high-performance liquid chromatographic procedure is suitable for identifying the above activities in different fractions obtained during separation and purification studies. The same approach was applied to the simultaneous determination of three types of endopeptidase activities in rat tissues based on the ability of the enzymes to hydrolyze different sites in succinyl-(Ala)3-p-nitroaniline.

Aminopeptidases↗
PubMed1984

Hemodynamic effects of nitroprusside on cardiovascular system.

The effects of nitroprusside (NP) on hemodynamics, especially on venous flow velocity of the inferior vena cava (IVC) were evaluated in 20 remote myocardial infarction patients. NP was given beginning at 10 micrograms/min, with subsequent increments of 10 micrograms/min every 5 minutes until the systolic blood pressure was reduced to about 30 mmHg. Pressure was measured by a catheter-tip micromanometer. Flow velocity of IVC was measured by a catheter-tip flow velocity probe. NP significantly decreased left ventricular systolic pressure, left ventricular end-diastolic pressure, mean aortic pressure, right ventricular systolic pressure, right ventricular end-diastolic pressure, mean pulmonary arterial pressure, mean pulmonary capillary wedge pressure, systemic vascular resistance index (SVRI) and left ventricular volume. Cardiac index (CI) was unchanged and stroke volume index was decreased. IVC pressure was unchanged, while right atrial (RA) pressure decreased. Subsequently, the pressure difference between IVC and RA increased significantly. The amplitude of IVC flow velocity decreased significantly. Twenty patients were classified into two groups according to whether or not the CI increased by NP. CI increased in 9 patients (group I) and decreased in 11 patients (group D). Compared to group D, control CI and the slope of end-systolic pressure-volume relation were less and the difference between IVC pressure and RA pressure was greater in group I. The patients with higher control SVRI had greater increase in CI during NP. In our study, the greater the depression of cardiac performance and the higher the SVRI, the greater the improvement of left ventricular pumping function during NP.

Adult↗
PubMed1984

[A case of alpha-fetoprotein-producing gastric carcinoma with unique macroscopical configuration].

A gastric carcinoma with unique macroscopical configuration was resected from a 63-year-old male patient. Serum level of alpha-fetoprotein (AFP) was markedly elevated (19,000 ng/ml), and AFP-positive cells were found in the carcinomatous tissues. The cytoplasm of the carcinoma cells appeared to be watery-clear by light microscopy, however, electron microscopy revealed abundant amorphous substances in their cytoplasmic matrix. The unique macroscopical configuration of the gastric carcinoma may reflect its biological resemblance to hepatocellular carcinoma. Such a case may be rare, but AFP production, per se, seems to be a rather universal phenomenon of gastric carcinomas.

Carcinoma↗
PubMed1984

[Nutritional management after massive resection of the pancreas].

Eleven patients after total pancreatectomy and 68 patients after pancreatoduodenectomy were reviewed for evaluating the importance of nutritional management after massive resection of the pancreas. Nutritional supply by IVH resulted in maintaining and improving the hepatic function under obstructive jaundice in clinical and experimental studies. Administration of elemental diet after the operation shortened the period of IVH, and had a effect to spare the requirement of exogenous insulin. One of the most important problems after pancreatectomy with extensive dissection of the lymph nodes and the nerves around superior mesenteric artery was a malnutrition which appeared frequently after long term follow-up. The malnutrition should be treated by IVH as soon as possible for preventing further aggravation of digestive and absorptive function of the alimentary tract. Oral or nasogastric tube administration of elemental diet is useful for weaning the patient from IVH, and it serves to prevent subsequent development of malnutrition. In six totally pancreatectomized patients studied, postabsorptive plasma concentration of Arg., Lys., Thr., Ala., Gly., Ser. and Pro. were greatly elevated compared to normal value, however these abnormalities were normalized by 1 to 3 mg of glucagon administration. Glucagon administration resulted in no significant change in daily nitrogen balance.

Humans↗
PubMed1983

Transport of [14C]coenzyme Q10 from the liver to other tissues after intravenous administration to guinea pigs.

After intravenous injection of [14C]coenzyme Q10 into guinea pigs, the blood level of radioactivity declined rapidly within 30 min. However, radioactivity in the blood subsequently increased, reached a peak at 8 h after the injection and thereafter decreased slowly. Since the liver uptake of radioactivity at 30 min after the injection was 87.8% of the dose and the increase of blood level was also seen in guinea pigs with bile duct fistula, it was concluded that the radioactivity taken up by the liver was redistributed to the blood and then transferred to other tissues. Tissue radioactivity levels were highest in the liver and spleen at 30 min after the injection and decreased thereafter. The levels in the blood and kidney peaked at 8 h, while those in the heart and brain peaked at 24 h and subsequently decreased. In contrast, the level in the adrenal gland was still increasing at 168 h after the injection; it rose sharply from 30 min, and at 24 h was higher than the level in any other tissue. Electrophoretic analysis showed that the radioactivity in serum at 8 h after the injection was associated with lipoproteins. It was confirmed by thin layer radiochromatography that the radioactivities in serum and liver at various times were due to coenzyme Q10 and coenzyme Q10 hydroquinone.

Animals↗
PubMed1983

Kinetics of d-tubocurarine disposition and pharmacologic response in rats.

After bolus intravenous dosing of d-tubocurarine (d-TC) to rats, the twitch heights of the tibialis anterior muscle indirectly stimulated were followed, and its decrease was defined as pharmacologic response of d-TC. The relation between dose and response intensity was found to be well described with Hill's equation. According to a theory proposed by Smolen, Hill's equation was also applicable to the biophase d-TC concentration-response relation; the time courses of the relative biophase d-TC concentration indicated linear kinetics with dose levels less than or equal to 0.15 mg/kg and the occurrence of dose-dependent disposition with 0.30 mg/kg. After bolus i.v. dosing of 3H-d-TC, plasma d-TC concentration obeyed a dose-independent two compartment model with doses less than or equal to 0.15 mg/kg, but not with 0.30 mg/kg. This finding matched the above estimated with pharmacologic data. The active metabolite was not found in plasma and urine. The extent of d-TC plasma protein binding was independent of the wide range of plasma levels and its mean (+/- SD) value was 30.5 (+/- 3.8). Plasma d-TC levels and pharmacologic response intensity were well correlated by Hill's equation and a three compartment model (the general two and the biophase compartments) in the dose range less than or equal to 0.15 mg/kg.

Animals↗
PubMed1983

Elastase-like enzyme in the aorta of spontaneously hypertensive rats.

In an attempt to obtain information regarding vascular elastase in arterial hypertension, we examined biochemical changes in elastase-like enzyme activity, and the intravascular localization of elastase by immunohistochemical techniques in the aorta of spontaneously hypertensive rats (SHR). In the biochemical study, aortic elastase-like enzyme activity was significantly higher in SHR than in controls. Using an antibody against rat pancreatic elastase raised in the rabbit, it was demonstrated immunohistochemically that the enzyme was localized in the endothelial cells and subendothelial spaces in the aorta of control animals. In SHR, elastase was also demonstrated in medial smooth muscle cells and particularly in the modified smooth muscle cells in areas of intimal thickening. Some vacuoles in the smooth muscle cells also showed positive enzyme staining. Elastase seems to play an important role in the development of hypertensive vascular changes.

Animals↗
PubMed1983

Coronary arteriography and left ventriculography during spontaneous and exercise-induced ST segment elevation in patients with variant angina.

The present study is an angiographic demonstration of coronary artery spasm during both spontaneous and exercise-induced angina in three patients with variant angina. In each case, clinical, ECG, coronary angiographic, and left ventriculographic observations were made at rest, during spontaneous angina, and during exercise-induced angina. The character of chest pain was similar during spontaneous and exercise-induced episodes. ST segment elevation was present in the anterior ECG leads during both episodes. The left anterior descending coronary artery became partially or totally obstructed during both types of attacks. When coronary spasm was demonstrated during both types of attacks, left ventriculography disclosed akinetic or dyskinetic wall motion in the area supplied by the involved artery. In those patients with reproducible exercise-induced ST segment elevation and chest pain, thallium-201 scintigraphy showed areas of reversible anteroseptal hypoperfusion. Thus in selected patients exercise-induced attacks of angina were similar to spontaneous episodes.

Angina Pectoris, Variant↗