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Biomedical subjects

M Takano

Publications and source records attributed to M Takano.

At least 451 records · Page 25Linked to original sources
PubMed1981

Natural interferon-producing cells in mice.

When mouse lymphoid cells derived from untreated C57BL/6 mice were cocultivated in liquid cultures with L-cell monolayers for 3 h, overlaid with soft agar, and then further incubated for 12 h, protected foci of L cells against vesicular stomatitis virus infection were formed. Many strains of mice have been found to have the protected focus-forming cells on the L-cell monolayers. The formation of the protected foci was completely suppressed by addition of cycloheximide into soft agar. When anti-interferon (type I) antiserum was added to soft agar, there was a decrease in focus counts of about 80%. These experimental results indicated that the formation of protected foci by untreated mouse lymphoid cells was mediated for the most part by type I interferon that was produced without addition of special inducer. We have designated these focus-forming cells as natural interferon-producing cells (NIPC). NIPC belong to the glass-adherent fraction, and Thy-1 antigen, immunoglobulin, and Ia antigen could not be detected on the surface of the NIPC. NIPC were detected in congenitally athymic nude mice. These findings suggest that NIPC belong to the Ia-negative macrophages. Mouse lymphoid cells obtained from germfree mice could form the protected foci on L-cell monolayers and could produce interferon without the addition of a special inducer. NIPC are considered to be a cellular background for spontaneous interferon production.

Animals↗
PubMed1981

[Behavioral and electroencephalographic effects of alprazolam and its metabolites (author's transl)].

The behavioral and electroencephalographic effects of alprazolam and its metabolites were investigated in mice, rats and rabbits, and compared with the data on diazepam, lorazepam and nitrazepam. Locomotor activity of mice in an open-field situation was increased with smaller doses of alprazolam and nitrazepam but not with diazepam and lorazepam. Alprazolam increased the hyperactivity induced by methamphetamine in mice. The anticonflict effects of alprazolam in rats were more potent than those of diazepam and lorazepam. In suppressing hyperemotionality and muricide of olfactory bulbectomized rats, alprazolam was more potent than diazepam and fairly equal to that of lorazepam. Muricide of raphe-lesioned rats was markedly inhibited by alprazolam. Mescaline-induced head-twitches in mice were more markedly increased with alprazolam than with nitrazepam and diazepam. Alprazolam, diazepam and lorazepam prevented both maximal electroshock and pentetrazol convulsions in mice. Alprazolam was more potent than diazepam and lorazepam in potentiating thiopental, ether and ethanol anesthesia in mice. In the impaired rotarod performance, alprazolam was more potent than diazepam and lorazepam in mice, but was much less potent than diazepam and lorazepam in mice, but was much less potent than lorazepam in rats. In conscious rabbits with chronically implanted electrodes, alprazolam induced a drowsy EEG pattern and depressed the EEG arousal response not only to auditory stimulation but also to mesencephalic reticular stimulation. The EEG effect of alprazolam was approx. twice that of diazepam. The pharmacological activity of alpha-hydroxyalprazolam was approx. one third that of alprazolam. However, 5-chloro-2-(3-hydromethyl-5-methyl-4H-1, 2,4-triazolo-4-yl) benzophenone showed no pharmacological activity. These results indicate that alprazolam possesses pharmacologic properties characteristic to benzodiazepines and that the activity is more potent than diazepam. In addition, alprazolam seems to have a specific effect on the central serotonergic mechanisms.

Aggression↗
PubMed1980

Characterization of altered BHK cells resistant to HVJ (Sendai virus) infection.

An altered baby hamster kidney cell culture which resists the c.p.e. of HVJ (haemagglutinating virus of Japan - the Sendai strain of parainfluenza I virus) has been obtained and characterized. These cells, designated BHK-R, were originally obtained by prolonged cultivation of cells surviving HVJ infection; they have been subcultured in the presence of HVJ. No infectious virus was recovered from BHK-R cells and no evidence for the presence of HVJ antigens in the cells was demonstrated by immunofluorescent staining. When BHK-R cells were inoculated with HVJ the growth of challenge virus was suppressed and no obvious cytopathic changes were detected, while these cells normally supported the replication of mumps, influenza, Newcastle disease, vesicular stomatitis or Sindbis viruses. BHK-R cells became susceptible to HVJ infection after serial subculture in growth medium free of HVJ. It was suggested that sialic acid residues present in the surface of BHK-R cell membranes and responsible for adsorption of HVJ were split off by the action of neuraminidase of virus particles, resulting in inhibition of the attachment of challenge virus of HVJ.

Adsorption↗
PubMed1980

Mutation induced by drying of Escherichia coli on a hydrophobic filter membrane.

Drying of Escherichia coli to a required cellular water level was conducted on a hydrophobic membrane at the corresponding relative humidity. Mutation from an arginine auxotroph to the prototroph was induced by drying to a water activity (aw) of 0.53 and below, but not to an aw of 0.75 and above. The critical aw below which mutation occurred in the course of drying was similar to that for induction of deoxyribonucleic acid (DNA) strand breakage in the bacteria. Some ultraviolet or gamma-irradiation-sensitive strains, e.g., strains of carrying recA, recB, and uvrA recA were more sensitive to drying than the wild-type strains or strains carrying uvrA and polA. The DNA strand breakage of every strain was observed to be to a similar extent after drying to an aw of less than 0.53. The drying-resistant strains repaired the damaged DNA partially during postdrying incubation in a growth medium but not in phosphate buffer solution, while the drying-sensitive strains could not at all. Significant mutation on drying occurred in the wild-type strains, strains carrying uvrA and polA, but not in strains carrying recA. It is, therefore, concluded that the mutation is caused by errors in rec-dependent repair of the drying-induced breakage in DNA.

Centrifugation, Density Gradient↗
PubMed1980

Enumeration of immune interferon-producing cells induced by allogeneic stimulation.

We succeeded in enumerating interferon-producing cells induced by allogeneic stimulation, and proved that they were indeed T lymphocytes. The peak level of these cells in spleen was attained on day 5 after immunication, was maintained for about 2 days, and declined thereafter. Titers of interferon produced in vitro by sensitized spleen cells were maximum on day 7. This suggests that the maturation of immune interferon-producing cells follows cell proliferation after antigen stimulation.

Animals↗
PubMed1980

Generation and maintenance of immune interferon-producing cells induced by allogeneic stimulation in mice.

When spleen cells derived from C57BL/6 mice immunized with L cells 7 days previously were cocultured with antigenic cells, immune interferon appeared in the culture fluid. We analyzed the tissue distribution of the immune interferon-producing cells (IIPC) which appeared in various lymphoid organs after allogeneic stimulation. Although fluid from cocultures of L-cell-sensitized thymocytes and L-cells could not detect interferon activity consistently, small numbers of IIPC could be detected by using the enumeration method of IIPC. The generation, maintenance, and nature of IIPC emerging in the spleen were different depending on how the host mice were immunized. Multiple antigenic stimulations were more effective and induced longer-lasting immune interferon production than a single stimulation. IIPC induced by a single stimulation appeared to be sensitive to cortisone, vinblastine, and cyclophosphamide and were relatively short lived. In contrast, IIPC induced by multiple stimulations seemed to be partially resistant to these drugs and long lived. When mice were immunized with intact L-cells, carrageenan, a known antimacrophage agent, had no effect on immune interferon production. However, when mice were immunized with solubilized L-cell antigen, this drug displayed a suppressive effect on immune interferon production.

Animals↗
PubMed1980

Purification and biochemical characterization of nuclear ribonucleoprotein antigen using purified antibody from serum of a patient with mixed connective tissue disease.

We have achieved a high degree of purification of nuclear ribonucleoprotein antigen from calf thymus nuclear extract through antibody affinity chromatography. Antibody to nuclear ribonucleoprotein was purified from the serum of a patient with mixed connective tissue disease and Sepharose 4B was covalently coupled with the purified human antibody. The sodium thiocyanate eluate from the affinity column contained active ribonucleoprotein antigen and the specific activity of the antigen in this eluate was 488 times higher than the original nuclear extract. The protein component of the eluate consisted of six polypeptides determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Two of them were shown to be antigenic by a hemagglutination inhibition test. The molecular weights of these two peptides were approximately 13,000 and those of the other four were 13,000, 13,000, 30,000, and 65,000. The ribonucleic acid component of the eluate was shown by urea-polyacrylamide gel electrophoresis to contain five polynucleotides. Two of the five, estimated to contain 40 and 60 nucleosides, had antigenic activity. The other three polynucleotides which had more than 77 nucleosides had no antigenic activity. No modified nucleosides were found in these ribonucleic acid molecules. Even in this highly purified ribonucleoprotein antigen, Sm antigen was detected by immunodiffusion. This evidence indicated that there are some molecular associations between ribonucleoprotein and Sm antigens as has previously been suggested.

Amino Acids↗
PubMed1979

The analysis of alkaline phosphatase isoenzyme using 4-methylumbelliferyl phosphate as substrate on a cellulose acetate membrane.

A new procedure is established for the analysis of alkaline phosphatase isoenzymes. The electrophoretic separation on cellulose acetate membrane coupled with the detection of alkaline phosphatase activity with 4-methyl-umbelliferyl phosphate as a substrate is described. The proposed method would be useful for the analysis of sample of micro-scale quantities and low activities.

Alkaline Phosphatase↗
PubMed1979

Protection of mice against virulent virus infection by a temperature-sensitive mutant derived from an HVJ (Sendai virus) carrier culture.

Experimental infection with HVJ (haemagglutinating virus of Japan-the Sendai strain of parainfluenza 1 virus) in mice was studied. Aerosol infection of newborn mice with the wild-type virus (HVJ-W) retarded the development of body weight and killed the animals within a few weeks. Large amounts of virus were isolated from both the lungs and the nasal turbinates of infected mice. In contrast, newborn mice exposed by inhalation to a temperature-sensitive (ts) mutant (HVJ-pB) derived from an HVJ carrier culture showed no clinical signs and grew equally well as mock-infected animals. No infectious virus could be recovered from the lungs although the ts mutant grew to moderate titre in the nasal turbinates. The prior inoculation of newborn mice with the ts mutant virus induced a state of significant resistance to subsequent challenge with the virulent wild-type virus. No replication of challenge virus in both lungs and nasal turbinates could be detected and the animals were protected a lethal infection. It is suggested that an avirulent temperature-sensitive mutant which has lost the capacity to replicate in the lower respiratory tract but is still capable of multiplying in the nasal turbinates may be a promising candidate for use in live vaccines especially against the infectious disease of the lower respiratory tract.

Animals↗
PubMed1979

Deoxyribonucleic acid strand breaks during drying of Escherichia coli on a hydorohobic filter membrane.

Cells of Escherichia coli mounted on a hydrophobic filter membrane were dried under various vapor pressures. A mutant defective in deoxyribonucleic acid repair (uvrA recA) was more sensitive to drying at a water activity of 0.53 or below than the parent strain but not at a water activity of 0.75 and above. Sucrose gradient studies showed that single- and double-strand breaks of deoxyribonucleic acid occurred at a water activity of 0.53 or below, but no breaks could be observed at a water activity of 0.75 or above. These results were observed in all cells rehydrated with 0.03 M tris (hydroxymethyl) aminomethane-hydrocholoride buffer solution at 0 or 37 degrees C, in the presence or absence of oxygen, with saturated water vapor or with a hypertonic solution followed by a gradual dilution. Freezable water was detected in the cells only at a water activity above 0.75 by differential scanning calorimetry. Removal of unfreezable water of cells in the drying, therfore, might induce deoxyribonucleic acid strand breaks.

DNA Repair↗
PubMed1979

Examination of latent infection in germfree mice for some murine viruses.

Sera from some groups of germfree mice were examined for reactivity against Sendai, reo 3, Theiler's GD VII, ectromelia, and mouse hepatitis virus antigens. Of 51 sera collected in September and October 1976 and in August and September 1977 from one germfree mouse breeding colony, there was no positive reaction against all the antigens tested. Moreover, the attempt of virus isolation from homogenates of various organs including lungs, liver, kidneys, and intestines of 6 germfree mice was unsuccessful.

Animals↗