Biomedical subjects

K Takahama

Publications and source records attributed to K Takahama.

At least 19 recordsLinked to original sources

PubMed1992

The influence of neuraminidase treatment on tracheal smooth muscle contraction.

To examine the role of sialic acid in the respiratory tract, the influence of neuraminidase from Clostridium perfringens was investigated on contractions of isolated guinea-pig and rat trachea and on histamine release from guinea-pig lung tissue. Treatment with 2.0 units/ml of neuraminidase at 37 degrees C and pH 7.4 for 30 min caused an approximately 60% removal of total N-acetylneuraminic acid, a representative sialic acid, from muscle from guinea-pig and rat trachea. Neuraminidase concentration dependently induced histamine release from guinea-pig chopped lung tissue, but has no effect on contractions produced by acetylcholine, histamine and 5-hydroxytryptamine. Pretreatment with 2.0 units/ml of neuraminidase inhibited the contraction induced by antigen (ovalbumin) or compound 48/80. These findings suggest, at least in part, that sialic acids sensitive to neuraminidase are involved in the regulation of histamine release but not tracheal contraction.

Acetylcholine↗

PubMed1992

Both beta 1- and beta 2-adrenoceptors are involved in mediating phosphatidylcholine secretion in rat type II pneumocyte cultures.

A primary culture of rat type II pneumocytes was used for the pharmacological and functional characterization of beta-adrenoceptor subtypes. The beta-adrenoceptor agonists, isoprenaline, dobutamine and procaterol concentration dependently increased the secretion of phosphatidylcholine. These effects were attenuated by propranolol. The effect of dobutamine was attenuated by atenolol, and that of procaterol by ICI 118,551. Isoprenaline-induced secretion was attenuated by the combination of the two blockers but not by each one alone. In conclusion, both beta 1- and beta 2-adrenoceptor subtypes mediate phosphatidylcholine secretion in rat type II pneumocytes.

Adrenergic beta-Agonists↗

PubMed1992

Glycyrrhizin and glycyrrhetinic acid determination from formalin-fixed tissue.

Glycyrrhetinic acid (GA), the main metabolic product of glycyrrhizin (GLY), could be detected in formalin-fixed tissue from a man who died 6 hours after therapeutic administration of a GLY-containing agent. GA was extracted from homogenized formalin-fixed liver tissue and 3 ng GA/g could be detected by HPLC. The extraction from formalin-fixed liver tissue gave the same retention time peak as the GLY control. GA could also be detected by mass spectrometry in the blood sample. This confirms that the man had received a GLY-containing agent for therapeutic use prior to his death and that GA can be determined from formalin-fixed tissue.

Anti-Inflammatory Agents↗

PubMed1992

Intestinal tuberculosis: findings on double-contrast barium enema.

Seven cases of intestinal tuberculosis in an active stage were studied by the double-contrast barium enema (DCBE) method. Formerly, diagnosis of intestinal tuberculosis in the early stage by single-contrast barium enema (SCBE) and barium meals was based on functional phenomena, such as spasm and hypermotility of the ileocecal region. Presently, this can be better accomplished by DCBE. DCBE enables the detection of shallow ulcers with their characteristic elevated margins. These ulcers are frequently slim and transversally oriented. Confluence of ulcers may create whole girdle ulcers or affect entire segments. In more advanced stages, characteristic deformities, also evident by SCBE, such as symmetrical annular stenoses, shortening, retraction, pouch formation, and the frequently observed pathology of the ileocecal valve and the cecal region, acquire a new dimension with DCBE.

Acquired Immunodeficiency Syndrome↗

PubMed1992

A sensitive sandwich enzyme immunoassay for gamma-seminoprotein and its application to sex discrimination of blood and bloodstains.

A sensitive sandwich enzyme immunoassay for gamma-seminoprotein (p30, prostate-specific antigen) is described for sex discrimination of blood and bloodstains. A polystyrene ball coated with rabbit anti-gamma-seminoprotein IgG was incubated with gamma-seminoprotein and, after washing, with affinity-purified rabbit anti-gamma-seminoprotein Fab'-horseradish peroxidase conjugate. Peroxidase activity bound to the polystyrene ball was assayed by fluorometry using 3-(4-hydroxyphenyl)propionic acid as hydrogen donor. The detection limit of gamma-seminoprotein was 0.15 pg per assay. Blood levels of gamma-seminoprotein, measured using 1-10 microliters of blood, were at least 3.3-fold higher in male adults than in female adults. The ratio of gamma-seminoprotein in terms of pg to hemoglobin in terms of mg was significantly higher in male adults than in female adults. Thus, the measurement of gamma-seminoprotein or both gamma-seminoprotein and hemoglobin was useful for the discrimination of blood and bloodstains of male and female adults, although with some limitations.

Adolescent↗

PubMed1992

Removal of extracellular Mg2+ suppresses sulfation of glycoconjugates secreted from rabbit trachea in culture.

The influences of extracellular Ca2+ and Mg2+ concentrations on the basal secretion of glycoconjugates from rabbit trachea in organ culture were examined. Over 80% of the 35S-labeled and [3H]glucosamine-labeled glycoconjugates secreted by the trachea were digested upon incubation with chondroitinase ABC. The basal secretion did not occur in the medium at 4 degrees C, indicating an energy-dependent process. The basal secretion at 37 degrees C of 35S-labeled glycoconjugates was prominently suppressed in Mg(2+)-free Tyrode solution but not in Ca(2+)-free Tyrode solution containing ethyleneglycol bis(2-aminoethylether)tetraacetic acid (EGTA). In contrast, the basal secretion of [3H]glucosamine-labeled glycoconjugates was not affected by the Mg2+ concentration in the medium. The results suggest that extracellular Mg2+ largely contributes to sulfation of glycoconjugates basally secreted from rabbit trachea.

Animals↗

PubMed1992

A sandwich enzyme immunoassay for liver-specific antigen and its forensic evaluation.

We attempted to develop a method for the determination of liver injuries, using a liver-specific antigen as a marker. The liver-specific antigen (LSA) was purified from the human liver and the antibody to the human LSA only reacted with the liver extract using the immuno-dot-blotting technique. Depending on the immunohistochemical study, the LSA was found to be located within the cytoplasm of hepatocytes. A sensitive and specific sandwich enzyme immunoassay was then developed for the measurement of LSA. The detection limit of human LSA was 1 fmol/tube (52 pg/tube) and this assay was not affected by hemolysis. The LSA levels in serum and blood from healthy subjects were distributed within a range below the detection limit. The LSA levels in the blood from cadavers whose livers had been damaged, were markedly elevated in comparison with the normal levels found in other cadavers (10-140 fold). No cross-reaction was observed with the liver extracts from several species (mouse, rat, guinea pig and rabbit). These results suggest that the measurement of LSA levels in blood will become a useful marker for the detection of liver injury.

Biomarkers↗

PubMed1992

[Trace analysis for drugs and poisons in human tissues].

Despite continuous developments of analytical techniques in terms of sensitivity and accuracy, uncountable increase in number of chemical substances are brought into the field of forensic sciences to be analyzed. Based on the idea that progress in analytical technique to cope with the change of situation is always required, a research team including 10 members was organized to set up the most advanced methods at present to analyze the important drugs and poisons in biological materials for forensic purposes. Stimulant drugs such as methamphetamine and amphetamine were studied on the improvement of extraction procedure prior to mass spectrometric analysis. A conventional solvent extraction method was replaced by an extraction technique using Extrelut column. The technical procedure was simplified and the accuracy of measurement was improved. The changes in CO-Hb concentration in the whole blood in storage was examined with regard to the lapse of time and temperature, where a differential spectrophotometry was used. Useful information could be obtained from practical aspects. Analytical conditions of gas chromatography were revised on volatiles including alcohols, especially as to column conditions. The use of capillary column was recommended for sensitivity and peak separation. The optimum conditions for detecting barbiturates in the blood were examined. The combination of Sep-pak C18 cartridge with a capillary column for gas chromatography using nitrogen phosphorus detection was found preferable. Mass spectrometry of various kinds of local anesthetics was studied. Quantitative analysis of the drugs was examined on gas chromatography with a surface ionization detector. Three types of insecticides including organophosphorus, chlorinated and fluorine compounds were analyzed by gas chromatography/mass spectrometry in order to establish a sensitive and selective method. The detection limits, calibration and reproducibility were examined. Herbicide, paraquat, was examined on the sensitivity, recovery, required time and costs in connection with methods of pretreatment and analytical procedure. A secondary spectrophotometry was found useful practically. Antimony in biological tissues was analyzed, using a flameless atomic absorption spectrometer with carbon tube atomizer. The time for analysis was reduced, and sensitivity was improved. Immunoassay method was examined from general aspects on drugs and hormones. Using antibodies specific to haptens, the dynamics of such antigens as drugs and hormones in the body tissues were observed. Interfering substances at the time of toxicological analysis were checked in order to obtain reliable information. Exact identification was found possible by using gas chromatography/mass spectrometry. As described above, the research was made from the practical aspects of forensic toxicology, and meaningful results could be obtained from each study.

Animals↗

PubMed1991

Stimulation of pulmonary surfactant secretion by activating neutrophils in rat type II pneumocytes culture.

The influence of activating neutrophils on the secretion of phosphatidylcholine (PC), the predominant component of pulmonary surfactant, was examined using primary culture of rat type II pneumocytes. Simultaneous addition of neutrophils and opsonized zymosan, but not neutrophils or opsonized zymosan alone, to type II pneumocytes caused a significant increase in PC secretion without affecting the release of lactate dehydrogenase, a marker of cytotoxicity. The increase in PC secretion was dependent on the number of activating neutrophils. In addition, pretreatment of culture with the combination of superoxide dismutase and catalase inhibited the increase in PC secretion. These findings indicate that activating neutrophils stimulate the secretion of pulmonary surfactant and that the stimulation is mediated by oxygen radicals.

Animals↗

PubMed1991

Isolation and characterization of liver-specific antigen.

The purpose of this work is to develop a method to determine liver injuries using liver-specific substances. Initially, the liver-specific antigen (LSA) was purified from the human liver. The human LSA found in the Sephadex G-100 gel filtration first peak, has been isolated and characterized from normal human liver water-soluble proteins. Purification of LSA was carried out by consecutive gel filtration, ammonium sulfate precipitation, and anion and cation ion exchange chromatography, while simultaneously monitoring its reactivity using the antibody against the first peak fraction of the human liver extract through Sephadex G-100 after absorption with serum and kidney extract. This antigen was found to have a single band in SDS electrophoresis (PAGE) and the M.W. of approximately 52 KD. By IEF electrophoresis, the isoelectric point of some constituents were found to be pI 5.8-5.9. In addition, the antibody to this antigen was examined for organ specificity using the immunoblotting technique against the human kidney, lung, heart, spleen, pancreas, skeletal muscle, brain extracts and serum, respectively. The immunogenicity and characteristics of this antigen were found to be different from other specific antigens in the liver, which have been previously reported.

Forensic Medicine↗

PubMed1990

Piperidine discriminates between the transient and the persistent components of the ACh-induced chloride current in Aplysia neurons.

ACh-induced Cl- -current (ICl) is well known to desensitize with two components: an initial fast phase followed by a second, more slowly developing phase. In the present study, the influence of piperidine, a normal constituent in vertebrates and invertebrates, on ACh-induced ICl in isolated neurons of Aplysia was investigated by using the concentration clamp in combination with the voltage clamp technique. Pretreatment with piperidine in doses greater than 2 X 10(-4)M depressed the transient ACh-induced ICl but had little effect on the persistent ICl. Kinetic study of the desensitization phase of ACh-induced ICl showed that the slow time constant of the desensitization phase of ACh-induced ICl was not altered by pretreatment with piperidine. The present results indicate that piperidine can discriminate between the fast transient and slow persistent components of ACh-induced ICl in Aplysia neurons, and also suggest that two components of the desensitization phase of ACh-induced ICl function in an independent manner.

Acetylcholine↗

PubMed1990

Pulmonary surfactant secretion in the type II pneumocytes in inflamed condition.

Basal PC secretion in the type II pneumocytes from bronchitic rats was the same as that in the type II pneumocytes from normal rats. Neutrophils activated by opsonized zymosan or PMA, stimulated PC secretion in type II pneumocytes without causing any cell damage. The stimulation required close accession or attachment of neutrophils and type II pneumocytes and was not affected by the pretreatment with either SOD, catalase, AA861 or alpha 1-antitrypsin.

Animals↗

PubMed1990

Voltage clamp analysis of the kinetics of piperidine-induced chloride current in isolated Aplysia neurons.

The effect of piperidine (Pip) on isolated Aplysia neurons was investigated using the voltage clamp and concentration clamp techniques in which neurons were perfused internally and externally with Na+,K+ free solution. Pip induced a Cl-current (ICl) in a dose-dependent manner for doses ranging from 10(-4) M to 10(-2) M. The dose-response curve gave an apparent dissociation constant of 8.4 x 10(-4) M and a Hill coefficient of 1.7. The current-voltage relationship was linear in the voltage range examined (-70 to +30 mV). The equilibrium potential for Pip induced current was close to the calculated equilibrium potential for chloride ions (ECl), (-10.7 mV). The activation phase of the ICl was characterized by a single exponential at all concentrations. The time constant of this phase decreased with increasing concentrations of Pip but did not depend on the membrane potential. The deactivation phase of the ICl proceeded on a single exponential curve at concentrations of Pip less than 5 x 10(-4) M, but on a double exponential at concentrations of 5 x 10(-4) M and higher. The deactivation time constant also decreased with increasing concentrations of Pip, but showed no potential dependence. Pip- and ACh-induced IClS were not blocked by 10(-4) M atropine. However, Pip-induced ICl was abolished with 10(-4) M d-tubocurarine (dTC), and the ACh-induced ICl was depressed by the same dose of dTC. These results suggest that Pip acts on at least two components of the nicotinic receptor-Cl channel complex in Aplysia neurons to elicit the ICl.

Animals↗

PubMed1990

Anti-allergic effect of N-acetylneuraminic acid in guinea-pigs.

The in-vivo anti-allergic effect of N-acetylneuraminic acid (NANA) in guinea-pigs passively sensitized with anti-ovalbumin rabbit serum has been studied. NANA (20 mg kg-1 i.v.) inhibited bronchial anaphylaxis and the release of histamine into bronchoalveolar lavage fluid. NANA dose-dependently inhibited heterologous passive cutaneous anaphylaxis and haemorrhaging in the passive Arthus reaction. However, it did not inhibit the release of histamine from sensitized minced lung tissue.

Anaphylaxis↗

PubMed1990

[Changes in lipid peroxides content and antioxidant enzyme activities on airway surface in SO2-induced bronchitic rats].

The changes in lipid peroxides (LP) content and antioxidant enzyme activities were investigated on airway surface during the aggravating process of bronchitis induced by SO2 exposure in rats. LP content in broncho-alveolar lavage fluid (BALF) has gradually increased from 3 weeks after starting of SO2 exposure. Whereas, the activities of antioxidant enzymes, superoxide dismutase and glutathione peroxidase, increased at 1 week and then gradually reduced from 3 weeks. The ratio of LP to each antioxidant enzyme activity in BALF of the exposed rats was higher than that of normal rats. Morphological changes of the lung, a decrease of PaO2 and an increase of PaCO2 of blood depended on the increase of LP on airway surface. These findings indicate that LP may be involved in the development of bronchitis.

Animals↗

PubMed1990

Influence of corticosterone on tracheal mucociliary transport in pigeons.

The effects of corticosteroids on tracheal mucociliary transport (MCT) were examined in pigeons. Intramuscular administration of corticosterone had no effect at 1.0 mg/kg, while at a larger dose of 5.0 mg/kg, it slightly, but significantly increased the MCT rate. Metyrapone significantly decreased the MCT rate, and the inhibitory action was blocked by 1.0 mg/kg corticosterone. The present study suggested that corticosteroids modulated the mucociliary clearance, especially under some diseases associated with a decreased level of endogenous corticosteroids.

Animals↗

PubMed1989

Increased production and/or secretion of pulmonary surfactant in rats by long term sulfur dioxide exposure.

Influence of long term SO2 exposure on the pulmonary surfactant in rats was studied by means of chemical analysis and microscopic verification. At a time after termination of the exposure period, the general symptom in rats was similar to that of bronchitis. The content of disaturated phosphatidylcholine, a main functional component of the pulmonary surfactant, significantly increased not only in broncho-alveolar lavage fluid but also in pulmonary microsomal fraction by long term SO2 exposure. Microscopic verification of alveolar type II cells from the bronchitic rats demonstrated the development of rough surface endoplasmic reticulums and an increase of the number of osmiophillic bodies. The results suggest that pulmonary surfactant production and/or secretion are activated in rats with bronchitis caused by long term SO2 exposure.

Animals↗

PubMed1989

Protective effect of surface-active phospholipids against the acid-inducing inhibition of the tracheal mucociliary transport.

Little is known about the physiological role of surface active phospholipids (SAP) in the central respiratory tract. In the present study, the effect of SAP on acid-inducing inhibition of particle transport by the tracheal mucociliary function was investigated in unanesthetized pigeons. SAP and acids were directly nebulized to the surface of the trachea. The composition of SAP was based on that of the pulmonary surfactant. The experiment was carried out under application of acetylcholine providing a constant mucociliary transport. SAP significantly diminished HCl- and H2SO4-inducing inhibitions of the mucociliary transport. Benzalkonium chloride also reduced the inhibition. The results suggest that SAP may be a protecting factor of the mucociliary clearance and that SAP may be connected with hydrophobicity not only of the alveolar surface but of the tracheal epithelium.

1,2-Dipalmitoylphosphatidylcholine↗