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Biomedical subjects

K Katayama

Publications and source records attributed to K Katayama.

At least 487 records · Page 27Linked to original sources
PubMed1983

An improved method for the determination of gamma-carboxyglutamic acid in proteins, bone, and urine.

A method of high-performance liquid chromatographic separation of the fluorescence derivative of gamma-carboxyglutamic acid (Gla) is presented. Alkaline hydrolysates of protein samples were reacted with o-phthalaldehyde in the presence of ethanethiol for 2 min, and the fluorescence derivative of gamma-carboxyglutamic acid was resolved from the other amino acids by a short column packed with silica-based anion exchanger under isocratic conditions. By this method, as low as 200 fmol of gamma-carboxyglutamic acid can be quantitatively analyzed within 10 min. The method presented here shortened the analysis time for Gla and was at least 10 times more sensitive than the method we described previously (Anal. Biochem. 117, 259-265, 1981). The application of this method to the formic acid-soluble or insoluble gamma-carboxyglutamic acid-containing proteins in chicken bone and the concomitant increase of gamma-carboxyglutamic acid content in chicken bone with age are reported.

1-Carboxyglutamic Acid↗
PubMed1983

Importance of left atrial function in patients with myocardial infarction.

Left atrial function was evaluated in patients with and without remote myocardial infarction. The simultaneous left atrial pressure recording and left atrial and left ventricular cineangiograms were obtained with a catheter-tip micromanometer. The pressure-volume curve of the left atrium was composed of an A-loop and a V-loop. The ratio of active atrial emptying to left ventricular stroke volume in patients with myocardial infarction was significantly larger than that in normal subjects (42 +/- 12% vs 29 +/- 10%, p less than 0.05). The left atrial work was also significantly greater in patients with myocardial infarction (1690 +/- 717 mm Hg X ml) than in normal subjects (940 +/- 426 mm Hg X ml, p less than 0.05). The ratio of active atrial emptying to left ventricular stroke volume and left atrial work were significantly related in both normal subjects and patients with myocardial infarction (gamma = 0.72, p less than 0.01). The left ventricular ejection fraction correlated inversely with left atrial work (gamma = -0.5, p less than 0.05). Left atrial work also showed a significant linear correlation with left atrial volume before active atrial emptying (gamma = 0.82, p less than 0.01). We conclude that the left atrial contribution to left ventricular function is increased in patients with remote myocardial infarction. This left atrial contribution to the left ventricle is attributed to the Frank-Starling mechanism in the left atrium.

Adult↗
PubMed1983

A note on saturable and inhibitory kinetics of p-aminohippurate renal transport in rabbits.

In order to establish quantitative expressions of inhibitory kinetics in renal tubular secretion of p-aminohippurate (PAH), bolus i.v. injection and constant i.v. infusion of PAH were loaded to rabbits. Time courses of plasma concentration and urinary excretion rate were analyzed using compartment model with saturable rate process. Effects of sulfamethizole (SMZ) constant infusion and bolus injection on PAH renal excretion were also examined. Multi-compartment model for concurrent disposition of PAH and SMZ is presented. Excretory processes are composed of non-saturable filtration, saturable secretion which is subject to mutual inhibition, and reabsorption.

Aminohippuric Acids↗
PubMed1983

Pharmacologic effects of metformin in relation to its disposition in alloxan diabetic rats.

The purpose of this investigation is to elucidate the relationship between the time course of pharmacologic effects and drug disposition after administration of metformin, an oral antidiabetic drug of biguanides. Alloxan diabetic rats and normal rats were used in the experiments. After administration of metformin, plasma glucose levels, blood pyruvate levels, blood lactate levels, plasma pancreatic glucagon immunoreactivity (pancreatic GI) and plasma gut glucagon like immunoreactivity (gut GLI) were determined as well as serum concentrations of metformin. In alloxan diabetic rats, gut GLI levels were significantly correlated to the logarithm of tissue metformin levels, calculated from serum metformin levels. The blood lactate, pyruvate and plasma glucose levels were also linearly related to gut GLI levels, after metformin administration. It was also clarified that metformin did not inhibit the intestinal absorption of glucose and that metformin presumably inhibited the hepatic gluconeogenesis. It is reasonable to consider that the effect of metformin on the gut GLI level is the primal effect, and that other pharmacologic effects such as plasma glucose lowering, blood lactate and pyruvate increasing effects are the consequences of the primal effect, at least in alloxan diabetic rats. While in normal rats, plasma gut GLI levels were not significantly related to metformin tissue levels, however, plasma glucose levels were considerably correlated with the logarithm of the plasma or tissue metformin levels. These results indicated that the effect of gut GLI was entirely masked by endogeneous insulin, which might be secreted by metformin administration.

Administration, Oral↗
PubMed1982

Studies on reduced and oxidized coenzyme Q (ubiquinones). II. The determination of oxidation-reduction levels of coenzyme Q in mitochondria, microsomes and plasma by high-performance liquid chromatography.

Reduced and oxidized coenzyme Q10 (Q10H2 and Q10) in guinea-pig liver mitochondria were rapidly extracted and determined by high-performance liquid chromatography (HPLC). The percentages of Q10H2 as compared to the total (sum of Q10 and Q10H2) were increased by the addition of respiratory substrates such as succinate, malate and beta-hydroxybutyrate (State 4). The levels of Q10H2 in State 4 were increased more extensively with electron-transport inhibitors such as KCN, NaN3 and antimycin A. These results indicate that the method for determining Q10H2 and Q10 by HPLC is quite useful for investigation of the physiological function of coenzyme Q in mitochondria and other organelles. The reduced and oxidized coenzyme Q levels of rat liver mitochondria, which contain both coenzyme Q9 and coenzyme Q10, were measured simultaneously. The results suggest that coenzymes Q9 and Q10 play a similar role as an electron carriers. The liver microsomes of guinea-pig contained approx. 133 nmol total coenzyme Q10 per g protein. The Q10H2 levels of microsomes were increased from 46.5 to 67.5 and 64.8% with NADH and NADPH, respectively. The plasma levels of total coenzyme Q were 0.92 microgram/ml for man, 0.35 microgram/ml for guinea-pig and 0.27 microgram/ml for rat. The reduced coenzyme Q were also present in those plasma samples. The levels of reduced coenzyme Q were 51.1, 48.9 and 65.3%, respectively.

Animals↗
PubMed1982

Radioimmunoreactive serum elastase levels and histologic changes during experimental pancreatitis in rats.

A radioimmunoassay system showed elastase levels of 128 to 232 ng/mL in normal rat serum. The average normal value was approximately 64-fold greater than the minimal detectable amount. No cross-immunoreactivity was found with human elastase 1, porcine elastase, and trypsin. The elastase and amylase levels in rat serum were measured during pancreatitis induced by trypsin (group 1) and normal saline solution (group 2). Within 15 minutes the serum elastase and amylase levels increased significantly and remained elevated. The serum elastase levels in group 1 were significantly higher than in group 2. Hemorrhagic pancreatitis was found in group 1 and edematous pancreatitis was found in group 2 five hours after induction of pancreatitis. Elastase levels in these tissues were significantly lower than those in normal tissue. The levels in ascitic fluid were higher than those found in serum.

Acute Disease↗
PubMed1982

Assessment of left ventricular relaxation in the diseased heart in man.

To examine the exponential nature of the left ventricular pressure (LVP) fall during isovolumic relaxation (IRP) in 59 patients (normal (N), 6; angina pectoris (AP), 13; myocardial infarction (MI), 24; and congestive (CCM, 6) and hypertrophic (HCM, 10) cardiomyopathies), LVP and dP/dt were measured by a Millar's catheter-tipped transducer. In P vs time relation during IRP was reasonably fitted by a straight line (r greater than 0.97) in all cases. Time constant (msec) in CCM (56.9 +/- 10.7), HCM (44.8 +/- 12.4) and MI (43.8 +/-7.4 higher (p less than 0.05) than in N (30.3 +/- 5.5), and peak (-) dP/dt (mmHg/sec) was lower (841 +/- 171, 1152 +/- 397 and 1270 +/- 211, respectively; p less than 0.05) than in N (1885 +/- 150), suggesting impaired LV relaxation in these groups. However, (-) dP/dt upstroke pattern was exponential only in both N and 8 of the AP. The (-) dP/dt upstroke in the remaining groups lost its exponential nature, showing rather a down ward-convex curvature which was especially prominent in CCM. This indicates non-exponential fall of LVP during IRP. Thus, the present results suggest that impaired relaxation disturbs the exponential nature of LV relaxation.

Adult↗
PubMed1982

Synthetic [Asu1,7] eel calcitonin increases phosphorus content in the hepatic bile of intact and nephrectomized rats.

The effect of synthetic [Asu1,7] eel calcitonin (CT) on phosphorus content in the hepatic bile was investigated in intact and nephrectomized rats. The subcutaneous administration of CT (80 MRC mU/100 g BW) produced a significant fall in the serum inorganic phosphorus concentration and a corresponding increase in the amount of phosphorus in the liver and kidney. These changes were observed even at the lowest dose of CT (40 MRC mU/100 g BW). The phosphorus contents in the spleen, heart, lungs and muscle were not significantly changed by CT administration. CT also provoked a marked elevation of phosphorus excretion into the bile. In nephrectomized rats, CT (80 MRC mU/100 g BW) caused a significant decrease in serum inorganic phosphorus concentration and a remarkable increase in liver phosphorus content. CT markedly increased phosphorus excretion into the bile of nephrectomized rats. These results support the theory that the hypophosphatemic effect of CT may be, at least partly, based on its action on liver in addition to kidney. This effect of CT on the liver may be the cause of increased excretion of phosphorus into the bile.

Animals↗
PubMed1982

Scanning electron microscopic studies on stigmas in rat ovaries.

Ultrastructural observations on stigmas in rat ovarian follicles have been performed by scanning electron microscopy. Stigmas were classified into two types under a dissecting microscope; extensively bulging vesicles (bleb-type stigmas) and small, flat avascular areas (flat-type stigmas). The bleb-type stigma had lost its surface epithelial cells extensively, and the flattened and densely arranged fibroblasts without fibrous structures were exposed. These fibroblasts had short, serrate, cytoplasmic projections where multivesicular structure-like granules were seen. By contrast, on the flat-type stigma a small region of exposed stroma was covered with fibrous structures. Removal of the fibrous structures by the HCl-collagenase method revealed that the exposed stroma consisted of stellate fibroblasts surrounding a small opening through which a few granulosa cells were about to discharge. When the cumulus mass was protruding, it was surrounded by the fibrous structures. These findings indicate that both the stellate fibroblast formation and the presence of fibrous structures are needed for the release of ova through the stigma.

Animals↗
PubMed1982

[Phase II study on peplomycin for esophageal cancer].

For the purpose of verifying the effectiveness of peplomycin, one of the derivatives of bleomycin, against carcinoma of the esophagus and the safety of it, the analysis of the data for total 113 cases collected from 25 institutions in Japan was made. The results are as follows. It was effective in 19 out of 74 evaluable cases of carcinoma of the esophagus (25.7%). In case of treatment with peplomycin alone, it was effective in 6 out of 39 cases (15.4%). In case of the combination treatment with peplomycin and some other therapy, it was effective in 13 out of 35 cases (37.1%). As for the side effects, the incidence of fever was the highest in both the cases of peplomycin alone and the combination treatment such as 39.6% and 37.0%, respectively. Anorexia, nausea, vomiting, respiratory symptoms and tiredness were found in relatively many cases. In the clinical laboratory tests, the vital capacity after the treatment tended to be lower than that before the treatment, but there was little change in the hematological tests, pulmonary function test and renal function test.

Adult↗
PubMed1982

[Gonadotropin and plasma cyclic nucleotides].

Plasma cyclic nucleotides in some physiological conditions were measured in normal women and the changes of cyclic AMP were studied after the loading of gonadotropins in normal and castrated women. We demonstrated a circadian rhythm of cyclic AMP and its variation during menstrual cycle in normal women and also demonstrated its significant increase in pregnant women. But there was no significant variation of plasma cyclic GMP levels in those physiological conditions. Plasma cyclic AMP was increased by the simultaneous administration of HMG and HCG in both normal and castrated women. However, individual administration of HMG or HCG demonstrated that it was HCG that caused that increase in plasma cyclic AMP even in castrated women. To examine the extragonadal effects of HCG, cortisol, triiodothyronine (T3), thyroxine (T4) in the plasma were measured after the loading of HCG. The plasma cortisol level was influenced by HCG in neither normal nor castrated women. HCG did not cause any change of T3 or T4 in normal women; however it caused a marked increase in T3 with a small decrease in T4 in castrated women.

Chorionic Gonadotropin↗
PubMed1982

[Failure of positive feedback in hypothalamo-pituitary-system in aged women and its recovery with estrogen treatment].

The positive feedback function of the hypothalamo-pituitary system in aging women was investigated by means of intravenous injection of conjugated estrogens. Marked LH surge was observed in both sexually mature young (20-35 y.o.) and premenopausal (35-49 y.o.) women after the intravenous injection of 20mg of conjugated estrogens. However, merely a small LH surge was observed in postmenopausal climacteric (50-55 y.o.) women, and no LH surge in aged (over 56 y.o.) women. In the patients with hypergonadotropic hypogonadism who are in the same age as sexually mature women, no LH surge was induced by conjugated estrogens. But positive feedback test done after oral administration of conjugated estrogens (1.25 mg/day) for 14 days showed positive reaction in both the aged women and the patients with hypergonadotropic hypogonadism in whom no LH surge had been observed before estrogen priming. The present results suggest that the dysfunction of positive feedback in aged women is mainly due to the decreased levels of estrogen produced by the ovaries but not the primary organic or functional changes of the hypothalamus or the pituitary.

Adult↗