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Biomedical subjects

T Miki

Publications and source records attributed to T Miki.

At least 991 records · Page 55Linked to original sources
PubMed1980

Concanavalin A agglutinability of some enveloped RNA viruses modified by host cell transformation.

The dependence on concanavalin A (Con A) concentration of agglutinability of some enveloped RNA viruses grown in transformed cells was compared with that of those grown in nontransformed cells. The avian oncoviruses were purified by centrifuging to equilibrium in a combination equilibrium: viscosity gradient of potassium tartrate and glycerol after conventional isopycnic sucrose density gradient centrifugation. Avian oncoviruses were more agglutinable with Con A when grown in transformed cells than when grown in nontransformed cells. Vesicular stomatitis virus grown in transformed cells was also more agglutinable than the virus grown in nontransformed cells. These results agree with the concept that the envelopes are modified by host cell transformation and that, therefore, viruses grown in transformed cells are expected to be more agglutinable with Con A than those grown in nontransformed cell.

Agglutination↗
PubMed1980

Cloning of replication, incompatibility, and stability functions of R plasmid NR1.

The region of R plasmid NR1 that is capable of mediating autonomous replication was cloned by using EcoRI, SalI, and PstI restriction endonucleases. The only EcoRI fragment capable of mediating autonomous replication in either a pol+ or a polA host was fragment B. SalI fragment E joined in native orientation with the part of SalI fragment C that overlapped with EcoRI fragment B, and also two contiguous PstI fragments of sizes 1.6 and 1.1 kilobases from EcoRI fragment B-mediated autonomous replication. When these individual SalI fragments were cloned onto plasmid pBR313 or the individual PstI fragments were cloned onto plasmid pBR322, none of these single fragments could rescue the replication of the ColE1-like vectors in a polA host, even in the presence of a compatible "helper" plasmid derived from a copy mutant of NR1. In contrast to the results reported for closely related R plasmid R6, EcoRI fragment A of NR1 could not rescue the replication of ColE1 derivative RSF2124 in a polA(Am) mutant or in a polA(Ts) mutant at the restrictive temperature. Although capable of autonomous replication, EcoRI fragment B of NR1 (or smaller replicator fragments cloned from it by using other restriction enzymes) was not stably inherited in the absence of selection for the recombinant plasmid. When EcoRI fragment B was ligated to EcoRI fragment A of NR1, the recombinant plasmid was stable. Thus, EcoRI fragment A contained a stability (stb) function. The stb function did not act in trans since EcoRI fragment B was not stably inherited when a ColE1 derivative (RSF2124) ligated to EcoRI fragment A was present in the same cell. A cointegrate plasmid consisting of EcoRI fragment B of NR1 ligated to RSF2124 was also not stably inherited, whereas only EcoRI fragment B was unstable when both RSF2124 and EcoRI fragment B coexisted as autonomous plasmids in the same cell. The incompatibility gene of NR1 was shown to be located within the region of overlap between SalI fragment E and the PstI 1.1-kilobase fragment. A copy mutant of NR1 (called pRR12) was found to have greatly reduced incompatibility with NR1; this Inc- phenotype is cis dominant.

Cloning, Molecular↗
PubMed1980

Fluctuation of the plasma TRH level in normal subjects in a 4-hour observation period.

Radioimmunoassayable TRH and TSH were measured in plasma samples taken at 5 min intervals for 4 hr (2100-0200 hr) from 4 normal male subjects. Three subjects showed a TSH surge at 2135 hr, 2455 hr and 0150 hr, respectively. The mean plasma TRH level of the 4 subjects was 10.3-11.7 pg/ml. Plasma TRH showed random fluctuation, which did not coincide with the nocturnal increase in plasma TSH.

Adult↗
PubMed1980

Influence of thymosin and the supernatant of cultured mouse thymus reticuloepithelial cell on mouse immune responses.

Effects of the humoral factor extracted from the calf thymus (thymosin: Goldstein et al.) and the supernatant of cultured mouse thymus reticuloepithelial cell (TRC) on immunological functions of the mouse lymphocytes were studied, and the following conclusions were drawn: Thymosin treatment did not alter the capacity to form anti-SRBC antibody in adult mice which were lethally irradiated and reconsituted with bone marrow cells. When the spleen cells from JCL-ICR mice thymectomized within 24 hr after birth were cultured with thymosin or supernatant of cultured ICR-TRC, the Thy 1 positive cells were increased. A significant increase in the mitogenic (PHA, Con A) reactivity of BALB/C spleen cells was observed when these cells were preincubated in medium containing thymosin for 24 hr. The NZB spleen cells, however, exhibited spleen cells showed a slightly potentiated response only to Con A. Similarly, thymosin enhanced the MLC reaction of the spleen cells from BALB/C mice with preincubation for 2 hr, but not enhanced that from NZB mice.

Animals↗
PubMed1980

Controlled clinical evaluation of a 10% strontium chloride dentifrice in treatment of dentin hypersensitivity following periodontal surgery.

Sixty adult patients were examined for dentin hypersensitivity prior to periodontal surgery. Stimuli used included mechanical, cold water and compressed air blasts. A subjective assessment of the degree of hypersensitivity for each stimulus was recorded. This presurgical examination revealed 249 hypersensitive areas among 60 subjects. Following surgery there was over a 100% increase in the pain (hypersensitivity) score. Desensitization with a 10% strontium chloride hexahydrate dentifrice was begun 1 week after surgical treatment. After 7 weeks of dentifrice use the pain score was reduced 75.5% in the test group. This was a reduction to a point below the preoperative level. The placebo group showed a reduction of 34.2% which was still above the preoperative level. These results agree with other clinical studies that have demonstrated a desensitizing effect of strontium chloride.

Adult↗
PubMed1979

Specialized transducing phage lambda carrying the genes for coupling factor of oxidative phosphorylation of Escherichia coli: increased synthesis of coupling factor on induction of prophage lambda asn.

Studies were made of the synthesis of the coupling factor complex (F1--F0) of oxidative phosphorylation after prophage induction of a set of Escherichia coli strains lysogenic for defective transducing phage lambda asn, lambda uncA, or lambda bglC. The transducing phages had been isolated from a strain of E. coli carrying prophage lambda cI857 S7 within the bglB gene located near the unc gene cluster [Miki, T., Hiraga, S., Nagata, T. & Yura, T. (1978) Proc. Natl. Acad. Sci. USA 75, 5099--5103]. When lysogenic cells carrying lambda asn and lambda cI857 S7 were induced at high temperature, synthesis of the F1-ATPase portion of the complex increased to severalfold that of the noninduced cells. In contrast, no increase was observed upon thermoinduction of cells carrying lambda uncA or lambda bglC. The number of membrane sites that could bind purified F1-ATPase also increased significantly upon induction by lambda asn but not by lambda uncA or lambda bglC. In addition, F1-depleted membranes prepared from lambda asn-induced bacteria required more dicyclohexylcarbodiimide to seal the proton pathway than did those from noninduced bacteria. These results strongly suggest that lambda asn carries a set of bacterial genes coding for all the F1 polypeptides (the alpha, beta, gamma, delta, and probably the epsilon subunits) and at least some of the genes involved in formation of F0 polypeptides. Although lambda uncA carries the structural gene (uncA) for the alpha subunit of F1-ATPase, it apparently does not carry the whole set of F1--F0 genes.

Adenosine Triphosphatases↗