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Biomedical subjects

Y Abe

Publications and source records attributed to Y Abe.

At least 829 records · Page 46Linked to original sources
PubMed1989

Fixation of amino acids and oligopeptides by freeze-drying in polyacrylamide gel electrophoresis.

Following polyacrylamide gel electrophoresis in an acetic/formic acid buffer, pH 2.0, in fabric reinforced gels, amino acids and oligopeptides could successfully be fixed in the gel by freeze-drying. Lyophilization of the fabric reinforced polyacrylamide gel after electrophoresis resulted in a dry film which absorbed ninhydrin solution quickly and uniformly, thus improving the detection limit for amino acids and oligopeptides with molecular weights ranging from 189-1045. Most amino acids were detected with a sensitivity of 0.1-0.25 microgram and for oligopeptides the detection limit was found to be 0.5-5 microgram.

Amino Acids↗
PubMed1989

Cell cycle-specific action of nerve growth factor in PC12 cells: differentiation without proliferation.

PC12 cells were manipulated in such a way as to permit the study of differentiation-specific responses independently from proliferative responses. Cells were starved for serum then exposed to nerve growth factor (NGF) or serum. Following addition of serum, cells incorporated thymidine in a synchronous manner. Subsequent to the wave of DNA synthesis, the cell number increased approximately two-fold. Addition of NGF to serum-starved cultures had no measurable effect on either parameter. Neurite outgrowth was more rapid and extensive and appearance of Na+ channels, measured as saxitoxin binding sites, more rapid than when NGF was added to exponentially-growing cells. Epidermal growth factor receptors were heterologously down-regulated by NGF with similar kinetics under both conditions. Induction of the proto-oncogene c-fos by NGF was also greater in the serum-starved cells than in exponentially-growing cultures. These results indicated that serum starvation resulted in synchronisation of the cultures and that NGF action may be cell cycle-specific. Analysis of the cellular response to NGF at different times during the cell cycle showed that c-fos was induced in the G1 phase but not in S or G2. Fluorescence-activated cell sorter analysis demonstrated that addition of NGF to exponentially-growing cells, resulted in their accumulation in a G1-like state. With regard to the study of the mechanism of NGF action, these results illustrate that measurements of NGF effects on specific components in the signal transduction pathway may be confounded by the use of exponentially-growing cultures.

Adrenal Gland Neoplasms↗
PubMed1989

The rate of lipid oxidation in septic rat models.

In order to examine the rate of lipid oxidation in sepsis, lipid infusion studies were carried out using two experimental models of septic rats, namely; an endotoxin group, and a cecum ligation and puncture group. Following the administration of glucose at a caloric amount equivalent to the measured resting energy expenditure (REE), the respiratory quotient (RG) values dropped promptly in the control group, but decreased only slightly in the septic groups. Following the administration of a lower dose of glucose (0.5 kcal/100 g B.W./hr), however, a lipid infusion promptly decreased the value of RQ in the septic groups. These results suggest that lipid oxidation was depressed in the septic groups and that the degree of depression was greatly influenced by the relationship between REE and the amount of administered glucose.

Animals↗
PubMed1989

Differential effects of 20-trifluoromethyl leukotriene B4 on human neutrophil functions.

A leukotriene B4 (LTB4) analog, 20-trifluoromethyl LTB4 (20CF3-LTB4), has been synthesized and evaluated with human neutrophils for effects on chemotaxis and degranulation. 20CF3-LTB4 was equipotent to LTB4 as a chemoattractant (EC50, 3 nM), produced 50% of maximal activity of LTB4, and competed with [H] LTB4 for binding to intact human neutrophil LTB4 receptors. In contrast to chemotactic activity, 20CF3-LTB4 in nanomolar concentrations exhibited antagonist activity without agonist activity up to 10 microM on LTB4-induced degranulation. The analog had no significant effect on degranulation induced by the chemoattractant peptide, N-formyl-methionyl-leucyl-phenylalanine (fMLP). Like LTB4, 20CF3-LTB4 induced neutrophil desensitization to degranulation by LTB4. The results indicate that hydrogen atoms at C-20 of LTB4 are critical for its intrinsic chemotactic and degranulation activities. The fact that 20CF3-LTB4 is a partial agonist for chemotaxis and an antagonist for degranulation suggests that different LTB4 receptor subtypes are coupled to these neutrophil functions. Desensitization of the neutrophil degranulation response to LTB4 can result from receptor occupancy by an antagonist, and therefore, the desensitization is not specific for an agonist.

Binding, Competitive↗
PubMed1989

Cytotoxicity against various cell lines of lipopolysaccharides purified from Bacteroides, Fusobacterium, and Veillonella isolated from infected root canals.

The cytotoxicity against two mesenchymal cell lines, L-929 and WI-38, and two epithelial cell lines, KB and HeLa S-3, of lipopolysaccharide (LPS) purified from strains of Bacteroides gingivalis, Fusobacterium nucleatum, and Veillonella parvula isolated from infected root canals was investigated. The inhibition of cell growth by these LPS's was considerable for mesenchymal cell lines, but mild for epithelial cell lines. The cytotoxic effect of F. nucleatum LPS was the greatest and that of B. gingivalis LPS was the least.

Bacteroides↗
PubMed1989

Primary structure of a ribonuclease from bullfrog (Rana catesbeiana) liver.

A pyrimidine base-specific ribonuclease was purified from bullfrog (Rana catesbeiana) liver by means of CM-cellulose column chromatography and affinity chromatography on heparin-Sepharose CL-6B, which gave single band on SDS-slab electrophoresis. The primary structure of the bullfrog liver RNase was determined. It consisted of 111 amino acid residues, including 8 half-cystine residues. From the sequence, it was concluded that three disulfide bridges in RNase A were conserved in the bullfrog RNase, that a disulfide bridge in RNase A [Cys65-Cys126 (RNase A numbering)] was deleted, and that a new disulfide bridge was created in the C-terminal part of the enzyme. In this frog RNase, the amino acid residues thought to be essential for catalysis in bovine pancreatic RNase A were conserved except for Asp121 (RNase A numbering). The sequence homology of the bullfrog liver RNase with bovine pancreatic RNase A was 30.6%. The sequence of bullfrog liver RNase was very similar to those of lectins obtained from bullfrog egg by Titani et al. [Biochemistry (1988) 26, 2189-2194] and R. japonica egg by Kamiya et al. [Seikagaku (in Japanese) (1989) 60, 733; and personal communication from Kamiya, Y., Oyama, F., Oyama, R., Sakakibara, F., Nitta, K., Kawauchi, H., and Titani, K.]. The sequence homology between the bullfrog liver RNase and the two lectins was 70.2 and 64.8%, respectively.

Amino Acid Sequence↗
PubMed1989

Changes of the serum amikacin (AMK) level in patients with serious acute renal failure treated by continuous arteriovenous hemofiltration (CAVH).

This study clarified changes in the serum amikacin (AMK) levels in the blood of 5 patients (4 men and 1 woman; average age 59.2 +/- 5.9 years) with serious acute renal failure treated by continuous arteriovenous hemofiltration (CAVH). The following principal results were obtained. (A) The average remaining rate of AMK in the blood after 6 h was 60.8 +/- 5.3% and 50.4 +/- 5.3% after 12 h. The average half-life period (t1/2 beta) of AMK in the blood during CAVH was 18.3 +/- 3.4 h. (B) The remaining rate of AMK in the blood after 12 h correlated significantly with the blood urea nitrogen (BUN) level (r = 0.71, p less than 0.05) and with the volume of urine excreted per day (r = -0.71, p less than 0.05). (C) The average lowest AMK concentration after 24 h for a continuous 17-day period was 3.3 micrograms/ml. These results suggest that the administration of 100 mg of AMK once a day is useful and safe for patients with serious acute renal failure treated by CAVH and that it will not accumulate in the body.

Acute Kidney Injury↗
PubMed1989

Cardiac output, renal blood flow and hepatic blood flow in rats with glycerol-induced acute renal failure.

Cardiac output (CO), renal blood flow (RBF) and hepatic blood flow (HBF) were measured by the microsphere method before (control) and at 4 and 10 h after the induction of acute renal failure by intramuscular injection of glycerol in water-drinking, long-term saline-drinking and long-term captopril (converting enzyme inhibitor)-drinking rats. At 4 h after glycerol injection, CO, RBF and HBF significantly decreased in all three groups. At 10 h after glycerol injection, CO, RBF and HBF recovered to 88% of the respective control levels in only the saline-drinking rats, whereas CO, RBF and HBF further decreased to 53, 38 and 58% of the control levels, respectively in the captopril-drinking rats. At this time, not only acute renal failure but also hepatic disorder developed in the water-drinking and captopril-drinking rats as indicated by elevations of serum creatinine, urea nitrogen, alanine aminotransferase and other blood chemistry levels. The development of acute renal failure was not suppressed by captopril, but by long-term saline load. Thus, we conclude that the decrease in CO is an important variable of the early decrease in renal and hepatic perfusion in glycerol-induced acute renal failure, and that the early recovery of HBF as well as RBF may play an important role in preventing the development of acute renal failure.

Acute Kidney Injury↗
PubMed1989

Epidermal growth factor receptors in plasma membranes of normal and diseased human thyroid glands.

We studied the characteristics of epidermal growth factor (EGF) receptors in plasma membrane fractions derived from normal and diseased human thyroid tissues. The mean maximal specific binding of EGF to membrane fractions of normal thyroid tissue (n = 25) was 1.46 +/- 0.47 (+/- SD) fmol/mg protein. The maximal specific binding was higher than the upper limit of the normal range (2.40) in 12 of the 39 (31%) differentiated carcinomas, 2 of the 3 (67%) undifferentiated carcinomas, and 1 squamous cell thyroid carcinoma. In contrast, the maximal specific binding in samples derived from adenomas (1.13 +/- 0.91), adenomatous goiters (0.92 +/- 0.56), and hyperplastic (Graves') thyroids (1.57 +/- 0.61) was not different from that in normal thyroid tissue. Scatchard plot analysis revealed that all thyroid membrane fractions had two classes of specific receptors for EGF. The mean association constant for the high affinity EGF receptors in normal thyroid tissue was 7.9 +/- 2.9 (+/- SD) X 10(9) mol/L-1, and the capacity was 22.9 +/- 7.0 fmol/mg protein. The capacity of the high affinity receptors was higher (P less than 0.05) in differentiated carcinoma (37.2 +/- 25.5) and undifferentiated carcinoma (32.7 +/- 11.6) than in normal thyroid tissue. In one squamous cell carcinoma, the capacities for the two classes of binding sites were about 15-fold greater than in normal thyroid tissue. In contrast, the association constants of the high affinity receptors from carcinomas (differentiated, 6.9 +/- 2.8; undifferentiated, 11.8 +/- 4.1; squamous cell, 8.2) were similar to that of normal thyroid tissue. In the thyroid tissues from eight patients with Graves' disease the capacity of the high affinity binding sites (37.5 +/- 12.3 fmol/mg protein) was higher than that in normal tissue, but the affinity (4.4 +/- 1.6 X 10(9) mol/L-1) was less, and the maximal specific binding was similar in the two types of tissue. These results suggest that a significant increase in the number of high affinity EGF receptors may play a role in the pathogenesis of human thyroid carcinoma.

Binding Sites↗
PubMed1989

[Study of infective complications in elderly patients with leukemia].

Elderly patients (more than 60 years old, n = 45) with leukemia who presented from 1976 to June 1987 were studied. Twenty-two were classified as the typical type and 23 were the atypical type (hypoplastic n = 10, low percentage n = 13) from the bone marrow findings at the time of diagnosis, among these 45 patients 102 infections, 48 of which occurred in patients with typical type leukemia, 31 infections occurred in hypoplastic leukemia and 23 in low percentage leukemia. Respiratory infections were the most common, regardless of the type of leukemia. The following pathogens, the majority of them were gram negative bacteria, were isolated before the administration of antimicrobial agents. Thirty infections were caused by multiple pathogens (typical 14, hypoplastic 10, low percentage 6). Of those 40% were caused by gram negative pathogens, 30% were due to both gram negative and positive pathogens. The causes of death in 37 patients included bleeding (n = 150 and infections (n = 13). Typical leukemia (n = 8) was the most common among patients who died of infection.

Aged↗
PubMed1989

[Double tracer whole body autoradiography using a short-lived positron emitter and a long-lived beta emitter].

We investigated glucose and amino acid metabolism in tumors and other organs using whole body autoradiography with a short-lived positron emitter and a long-lived beta emitter. The radioactive compounds used were 2-deoxy-2-[18F]-fluoro-D-glucose (18F-FDG) with a half life of 109.8 min and L-[methyl-14C]-methionine (14C-MET) with a half life of 5,730 years. A Donryu rat weighing about 150 g was subcutaneously inoculated at the back with experimental tumors of AH109A and AH272. 74 MBq (2 mCi) of 18F-FDG and 740 kBq (20 microCi) of 14C-MET was administered and after 30 min, the rat was sacrificed. Whole body frozen sections were obtained using autocryotome. For the 18F-FDG autoradiogram, the frozen sections were exposed to an X-ray film for 6 h. After seven days, these frozen sections were again exposed to 14C-MET for a week. Cross-contamination was minimized by adjusting the exposure time, the interval of exposures and the administered dose. The accumulation of the tracers was represented as the optical density ratio of the tissue of interest to the muscle. The tumor ratios were 12.5 for 18F-FDG and 8.6 for 14C-MET showing the highest accumulation in the whole body autoradiogram. In contrast the inflammatory tissue ratios were 1.27 for 18F-FDG and 0.77 for 14C-MET showing very low amino acid metabolism. With the present double tracer whole body autoradiogram, 18F-FDG accumulation was seen in the brain and the heart but not to the liver as against 14C-MET accumulation which was seen to the liver but not to the brain and the heart.

Animals↗
PubMed1989

Effect of deuterium oxide (D2O) on the IgE-mediated Ca2+ influx, arachidonic acid and histamine release in rat basophilic leukemia cells.

Deuterium oxide (D2O), which is known to stimulate microtubule aggregation, enhanced the IgE-mediated 45Ca2+ influx, (14C)-arachidonic acid and histamine release in rat basophilic leukemia cells (RBL-2H3) in the same dose-dependent manner (up to 90% (v/v]. We compared the interaction between D2O and a variety of groups of pharmacological agents. A microtubule depolymerizing agent, demecolcine, which inhibited the IgE-mediated (14C)-arachidonic acid and histamine release without affecting 45Ca2+ influx, was counteracted by 45% D2O. Taxol, a microtubule stabilizing agent, which had an inhibitory effect on the above three steps, was also reversed by 45% D2O. These results would support the previous data on the interaction between D2O and microtubules and would further suggest that the status of microtubule aggregation may be related to the secretory process. Calmodulin inhibitors (W-7, trifluoperazine) blocked the IgE-mediated 45Ca2+ influx, (14C)-arachidonic acid and histamine release in the same dose-dependent manner, but were counteracted by 45% D2O. In contrast, the effects of proteinase inhibitors (TPCK, TLCK), an adenylate cyclase inhibitor (ddAdo), a phosphodiesterase inhibitor (aminophylline), a phospholipid methylation inhibitor (DZA + Hcy) and microfilament blockers (cytochalasin B and D) were not counteracted by 45% D2O. These results would suggest that D2O may be associated with calmodulin directly or indirectly possibly through some relationship between calmodulin and microtubules.

Animals↗
PubMed1989

[Studies on the method of sterilization with ethylene oxide gas. 2. Residual EO gas on sterilized objects].

Ethylene oxide gas (EO gas) adsorbed onto sterilized objects was quantitated in an effort to take a safety measure against residual EO gas following its use in sterilization. We measured residual amounts of EO gas adsorbed onto laboratory wares, small medical tools and appliances just after post-sterilization airation to examine whether they were rendered entirely free from EO gas by the process. The results led us to arrive at the following conclusions: 1. EO gas was recognized to remain on sterilized objects even after allowing them to stand for about 16 hours following airation. 2. The amount of residual EO gas was smaller on metallic products and larger on rubber products (notably rubber gloves). An exceedingly high concentration of EO gas was noted to remain on a tooth-brush, among other plastic materials. These facts seem to indicate that the amount of residual EO gas is closely related to the texture and shape of materials to be sterilized. 3. As regards the potential toxicity of residual EO gas. However, their sensitivity was proved to be questionable, judgment on a result being subject to considerable individual variations. 4. Nevertheless, it is incontestable that these devices can at least provide a rough estimate of unavailing since monitoring by direct measurement of residual EO gas is virtually infeasible from a practical point of view.

Dental Instruments↗
PubMed1989

[Automatic control of total artificial heart to simulate the hemodynamics under natural heart circulation].

We developed control system of total artificial heart (TAH) during exercise simulating the circulatory response of natural heart. The following procedures were taken to develop this system. 1) Measurement of hemodynamics and physical activity rate (PAR) of natural heart goats during treadmill exercise. 2) Estimation of cardiac output from PAR using a non-linear model. 3) Development of a pneumatic artificial heart (AH) driver with high speed controllability and a control unit to deliver CO calculated from PAR beat by beat. 4) Evaluation of the physiological condition of the TAH goat during exercise controlled by this system. Using this control method, CO of TAH goats was similar to that of natural heart goats during treadmill exercise. Hypertension was observed during exercise. This hypertension was considered to be derived from two causes. One was high inflow and outflow resistance of cannulae between AH pump and living body. The other was the disorder of peripheral circulatory control mechanism in TAH animal. Such as increased sympathetic activity, insufficient secretion of atrial natriuretic polypeptide (ANP) and decreased sensitivity of peripheral circulatory system with ANP.

Animals↗
PubMed1989

Relationship between histologic type of primary lung cancer and carbon-11-L-methionine uptake with positron emission tomography.

L-[Methyl-11C]-methionine [( 11C]methionine) has proved to be one of the useful amino acids for the diagnosis of human cancer. We examined whether there was any correlation between [11C]methionine uptake and histologic type of primary lung cancer. Sixteen patients with nine squamous cell carcinoma, five large cell carcinoma, one small cell carcinoma, and one adenocarcinoma were studied using positron emission tomography (PET). All patients had high accumulation of [11C]methionine in lung tumors. We evaluated [11C]methionine uptake into the tumor by a semiquantitative value, DUR (Differential Uptake Ratio). There was significant difference (p less than 0.01, Mann-Whitney test) of [11C]methionine uptake between large cell carcinoma (3.98 +/- 0.27) and squamous cell carcinoma (2.92 +/- 0.30). The result suggested that there was correlation between [11C]methionine accumulation and the histologic type of lung cancer. This indicates a new potential applicability of [11C]methionine PET for the study of lung cancer.

Adenocarcinoma↗
PubMed1989

[Study of development of autoantibody to beta-adrenergic receptors in asthmatics].

An (125I) iodohydroxybenzyl pindolol (125IHYP) binding inhibition assay was performed. Various dilutions (1:5-1:500) of sera from asthmatics and controls were incubated with canine lung membranes for 60 minutes at 30 degrees C. 125IHYP was added to the membranes for 30 minutes at room temperature in the presence and absence of 10 microM 1-propranolol, and the samples were washed through a Gelman (Type A-E) glass fiber filter using a washing buffer. Radio activity was measured with Aloka gamma counter. In the presence of various serum dilutions from asthmatics, 125IHYP specific bindings of 0.16 fmol to 4.38 fmol were measured. 125IHYP binding was inhibited in a dose-related and nonspecific manner. Serum, albumin, L-histidine and L-cysteine also inhibited 125IHYP specific binding to beta-receptors. Percentages of inhibition of serum from asthmatics on 125IHYP specific finding to beta-receptors were -17.6% to +9.3%, which were compared with identical dilutions of control serum. There was no significant difference in 125IHYP binding inhibition assay between asthmatics and controls. From these results, development of autoantibody to beta-adrenergic receptors could not be detected in this study.

Animals↗