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Biomedical subjects

S Ida

Publications and source records attributed to S Ida.

At least 91 records · Page 5Linked to original sources
PubMed1984

Determination of cystamine by high-performance liquid chromatography.

A highly sensitive and specific assay method for cystamine using high-performance liquid chromatography has been developed. The method is based on postcolumn derivatization of cystamine with o-phthaladehyde in the presence of 2-mercaptoethanol and sodium hypochlorite. The separation of cystamine was achieved using a cation exchange column (ISC-05/S0504). The assay was linear over the concentration range of 2 to 200 pmol. For the application of this assay method to biological materials, the pretreatment with a cation exchange column (Dowex 50W X 8) was necessary to remove interfering o-phthaladehyde-reactive substances. Since cysteamine in biological materials was quantitatively converted to cystamine during these sampling procedures, this method was found to be suitable for assaying the cysteamine plus cystamine content in various organs and tissues. The cysteamine-cystamine content in various tissues of rat determined by the present assay method has been presented.

Animals↗
PubMed1984

Determination of hepatitis B virus DNA in serum by molecular hybridization.

Hepatitis B virus (HBV) DNA was detected by direct spotting of alkali-denatured serum on a nitrocellulose filter and molecular hybridization with cloned HBV DNA as the probe. Measurement of the autoradiographic signals as the intensity of hybridization allowed the quantitation of HBV DNA content in serum specimens in reference to cloned HBV DNA. Direct spotting of denatured serum was approximately three times as sensitive as the conventional method in which proteinase-treated serum was extracted with phenol-chloroform. The intensity of hybridization with 25 specimens of HB virion concentrates correlated well with DNA polymerase activity (r = 0.89, P less than 0.01).

Cloning, Molecular↗
PubMed1984

Alteration of cerebral taurine biosynthesis in spontaneously hypertensive rats.

Cerebral taurine biosynthesis in a spontaneously hypertensive rat (SHR) has been studied. Cysteine sulfinic acid (CSA) and cysteic acid (CA), possible key intermediates in taurine biosynthesis, were found in the rat brain, whereas no cysteamine-cystamine was detected. In the brain of SHR, a statistically significant decrease in the contents of CSA, CA, and taurine was noted in the cerebellum, hypothalamus, and striatum as compared with normotensive Wistar Kyoto rats. Similarly, it was demonstrated that the activity of cysteine dioxygenase, the enzyme catalyzing cysteine to CSA, was attenuated significantly in the same brain areas of SHR. In contrast, no alteration in the activity of CSA decarboxylase, the enzyme converting CSA to hypotaurine or CA to taurine, was observed. A decline in the percent conversion of [14C]cysteine to [14C]taurine was found also in tissue homogenates from the cerebellum, hypothalamus, and striatum of SHR, indicating that the declines in taurine content may be due to an attenuation of taurine biosynthesis, possibly at the step involving cysteine dioxygenase.

Animals↗
PubMed1984

Mast cells in bronchoalveolar lumen of patients with bronchial asthma.

Bronchoalveolar lavage was performed on patients with stable bronchial asthma to elucidate the existence and significance of mast cells in human bronchoalveolar lumen. The percentage of total mast cell population, in which 2 different types of mast cells could be identified morphologically in lavage fluids, was 0.25 +/- 0.19% (mean +/- SD) in asthmatic patients and 0.08 +/- 0.02% in control subjects. The number of mast cells in asthmatic patients was greater than in control subjects (p less than 0.05). The histamine content per mast cell in bronchoalveolar lumen was calculated to be 8.2 +/- 6.0 pg/cell in asthmatic patients and 15.3 +/- 10.8 pg/cell in control subjects, which suggests that the " releasability " of histamine is greater in asthmatic patients during asymptomatic periods than it is in control subjects, although the differences were not statistically significant. Our results suggest that an increase in the mast cell population of bronchoalveolar lumen is significant in the pathogenesis of bronchial asthma.

Adult↗
PubMed1984

A rabbit model for hypersensitivity pneumonitis.

A rabbit model of acute hypersensitivity pneumonitis was produced by immunization and subsequent inhalation of pigeon serum. The pathological features, consisting of alveolitis and interstitial granulomas, were similar to those reported previously in the experimental models. Repeated inhalation challenge of pigeon serum, however, did not develop chronic alveolitis but led to the fading of the disease. It was suggested that desensitization defined as the suppression of delayed hypersensitivity contributed to the mechanism of the fading of the disease. Repeated pigeon serum inhalation without previous immunization by the same antigen could produce a moderate interstitial pneumonitis but did not demonstrate a typical granulomatous histological change in lungs. It was necessary to use adjuvant for producing a complete animal model of hypersensitivity pneumonitis. Antigen-specific antibody response did not directly correlate with the development of the animal model of hypersensitivity pneumonitis.

Aerosols↗
PubMed1984

[Susceptibility of bacteria isolated from lower respiratory tract infections to antibiotics (1982)].

Two hundred seventy-six bacterial strains were isolated as possible causative pathogens mainly from sputum in 248 patients with lower respiratory tract infections at 12 medical institutions in various parts of Japan during the period from September 1982 to March 1983. Of these, 272 isolates including 28 Staphylococcus aureus strains, 38 Streptococcus pneumoniae strains, 107 Haemophilus influenzae strains, 68 Pseudomonas aeruginosa strains, 17 Klebsiella pneumoniae strains, 9 Escherichia coli strains and 5 strains of other species were tested in vitro for MICs of various antibiotics, and their drug sensitivity distributions determined. Data were also analyzed for distribution of cases by clinical entities, age and sex, interrelations between the types of infections and the species and frequency of isolation of organisms, and relations of the antimicrobial regimens at collection of clinical specimens to the species and frequency of isolation of the organisms. It engenders great interest that there was a significant increase in frequency of S. aureus isolation within 7 days after antibiotic therapy, compared to pretreatment isolation frequency, in the 1982 series. This seems to deserve further investigation in detail. The H. influenzae strains isolated with the highest frequency in 1981 and those in 1982 were examined as to susceptibility to several representative antibiotics, with interdrug comparisons: ABPC vs. SBPC, CTM vs. CMZ, and CMX vs. LMOX. The isolates demonstrated high degrees of susceptibility to these drugs and there was no conspicuous change in bacterial sensitivity to the drugs.

Adult↗
PubMed1984

[Antibiotic sensitivity of Branhamella catarrhalis isolated from respiratory tract infections].

The efficacy of antibiotics including some newly developed penicillins and cephems on clinically isolated Branhamella catarrhalis was evaluated in vitro. Among 44 strains of B. catarrhalis which were isolated from expectorated sputum of patients with respiratory tract infections 36 strains were proved to produce beta-lactamase. MICs of penicillins for beta-lactamase positive strains ranged from less than or equal to 0.05 to 3.13 micrograms/ml, while those for beta-lactamase negative strains were all less than 0.05 microgram/ml. MICs of cephems, on the other hand, ranged more variably, especially among beta-lactamase positive strains. The most effective cephem we tested was LMOX which could inhibit all the strains of B. catarrhalis at the concentration of 0.05 microgram/ml or less. Aminoglycosides as well as macrolides also showed sufficiently low MIC values. We therefore concluded that the confirmation of beta-lactamase production by B. catarrhalis seems to be indispensable for the determination of an antibacterial activity of beta-lactam antibiotics.

Amoxicillin↗
PubMed1984

Effect of influenza virus infection on allergic sensitization to aerosolized ovalbumin in mice.

An IgE antibody specific to ovalbumin was produced when C3H mice were first infected with influenza A virus before challenge with the aerosolized antigen. No antibody could be detected in those animals without preceding viral infection. Antigen inhalation immediately after virus infection could not induce the IgE antibody. A time lag of at least 2 days was required to sensitize the infected mice with inhaled antigen. The study revealed that allergic sensitization could be elicited only during the acute stage of the infection, but not in the convalescent stage. We concluded therefore that the inflammation of respiratory mucous membrane might allow inhaled antigens to penetrate the barrier, resulting in reaginic antibody production that has the capacity to serve as an allergic response.

Administration, Intranasal↗
PubMed1983

Simultaneous determination of cysteine sulfinic acid and cysteic acid in rat brain by high-performance liquid chromatography.

A sensitive and specific assay method for cysteine sulfinic acid (CSA) and cysteic acid (CA) using high-performance liquid chromatography has been developed. The method includes post-column derivatization of various amino acids with o-phthalaldehyde in the presence of 2-mercaptoethanol. The column packed with cation-exchange resin (ISC-07/S1504, Shimadzu Scientific Instruments, Inc., Kyoto, Japan) was used for obtaining general separation of amino acids except CSA and CA, while the separation of CSA and CA was achieved using a strong-base anion exchange (ISA-07/S2504, Shimadzu Scientific Instruments) column. The fluorescence peak area for CSA was linear between 20 pmol and 5 nmol, whereas that for CA was 10 pmol to 5 nmol. The regional distribution of CSA, CA, and other amino acids in the rat brain was studied using this new assay method.

Amino Acids↗
PubMed1983

Taurine biosynthesis in frog retina: effects of light and dark adaptations.

The retinal uptake and metabolism of cysteine, a precursor for taurine biosynthesis, were analysed using the bull frog. The [14C] cysteine uptake into isolated retina had some specific properties: It was rather temperature independent, required Na ions, was inhibited by ouabain but not by dinitrophenol, and exhibited saturation kinetics composed of two components. When retinal homogenate was incubated with 12-30 microM of L-[U-14C]cysteine, the accumulation of labeled alanine, cysteine sulfinic acid (CSA), cysteic acid (CA), hypotaurine, and taurine was detected. The metabolic conversions of [14C] cysteine to labeled alanine, hypotaurine, and taurine were linear over 90 minutes. Prolonged light adaptation (3 weeks) induced a significant reduction in the formation of labeled CA, CSA, hypotaurine, and taurine from [14C] cysteine. On the other hand, it was found that in dark-adapted retinae, the formation of labeled taurine from [14C] cysteine increased significantly in spite of the reduction in the formation of labeled CA. These results indicate that biosynthetic pathways exist for taurine from cysteine in frog retina, and that these metabolic pathways are involved in the regulation of retinal taurine content under continuous visual adaptation.

Adaptation, Physiological↗
PubMed1983

Cell-bound and circulating IgE antibody to herpes simplex virus.

Mice immunized with ultraviolet-inactivated herpes simplex virus (HSV) or injected with infectious virus developed IgE-specific antibody to HSV. Cell-bound IgE was detected by measuring the release of histamine from peritoneal mast cells challenged in vitro with virus antigens. Circulating IgE antibody was detected by sensitizing rat basophilic leukaemia (RBL-2H3) cells with sera from HSV-immunized mice and then challenging these cells with virus or control antigens to release histamine. IgE antibody may contribute to the pathogenesis of virus infections.

Animals↗
PubMed1983

Stress-induced alterations in metabolism of gamma-aminobutyric acid in rat brain.

The effect of a stressful manipulation on the metabolism of gamma-aminobutyric acid (GABA) in the rat brain was studied. Application of an immobilized stress to animals induced a significant increase in the striatal and hypothalamic GABA contents without affecting those in other central structures examined. It was also found that the increase in striatal GABA level preceded that in the hypothalamus. This increase in steady-state levels of GABA in the striatum and hypothalamus disappeared at 12 h after the termination of the application of stress for 3 h, which exhibited a maximal stimulatory action on the GABA contents in both central areas. The activity of L-glutamic acid decarboxylase was found to be significantly elevated in the striatum and hypothalamus following the stress application with a concomitant decrease in the content of L-glutamic acid, which is converted to GABA by the catalytic action of the latter enzyme. The in vivo turnover of GABA in the brain was estimated by taking advantages of the postmortem accumulation of GABA following decapitation and of the selective inhibitory action of a low dose of aminooxyacetic acid on the GABA degrading system, respectively. Analysis using these two different methods revealed that the cerebral turnover of GABA in vivo was not significantly altered under stressful situations despite of the increase in its steady-state level. These results suggest that central GABA system may respond to the input of painful stimuli resulting from the application of a severe physical and psychological stressor, in addition to the well-known functional alterations in catecholamine neurons. The functional significance of these alterations in the central GABA neurons is also discussed.

Animals↗
PubMed1983

[Effects of 4-(o-benzylphenoxy)-N-methylbutylamine hydrochloride (MCI-2016) on monamine metabolism in the brain].

Effects of MCI-2016 on the uptake, contents and turnover rate of monoamines were studied in the rat brain. MCI-2016 exhibited more potent inhibitory effect on the noradrenaline (NA) uptake than on dopamine (DA) and serotonin (5-HT) uptake. Especially, the inhibitory effect of MCI-2016 on the NA uptake in the hypothalamus was comparable to that of imipramine with the IC50 value of 4 X 10(-8) M. The levels of NA and its metabolite, MHPG-SO4, in the whole brain were significantly increased by 30 mg/kg, i.p. of MCI-2016. The peak effects were reached between two to 4 hrs after administration. The increase in 5-HT contents at the cortex were also observed by MCI-2016 (30 mg/kg, i.p.), with little changes in 5-HIAA contents. The levels of DA, HVA and DOPAC in the whole brain were not significantly influenced by MCI-2016. The turnover rate of NA was facilitated by 61.1% by 15 mg/kg, i.p. of MCI-2016. DA and 5-HT turnover rates were little affected by the same dosage of MCI-2016. In the case of imipramine (15 mg/kg, i.p.), however, it didn't increase the NA turnover, and in addition, it inhibited the 5-HT turnover. The increase in NA turnover rate induced by MCI-2016 was antagonized by 54.5% by 30 mg/kg, i.p. of atropine. Physostigmine (1 mg/kg, i.p.) also increased NA turnover rate which was also partially (62.6%) inhibited by atropine. These results may suggest that the effects of MCI-2016 on noradrenergic mechanisms were qualitatively different from those of tricyclic antidepressants. In addition, the results with atropine on the turnover rate may in part suggest a possible participation of the cholinergic mechanism on the turnover increasing effect of MCI-2016.

Animals↗