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Biomedical subjects

H Ohmori

Publications and source records attributed to H Ohmori.

At least 253 records · Page 14Linked to original sources
PubMed1989

[Prostatic tissue and fluid levels of lomefloxacin (NY-198)].

The concentration of Lomefloxacin (NY-198), a new quinolone, in human prostatic tissue and fluid was examined. Lomefloxacin was concentrated in prostatic gland and the mean ratios of prostatic tissue levels to serum levels (P/S) were 1.39-1.83 during 2 to 6 hrs after administration. Concerning prostatic fluid concentrations, there were no significant differences between healthy volunteers and patients with chronic prostatitis. The mean ratios of prostatic fluid levels to serum levels (Pf/S) were 0.36-0.77 during 1 to 4 hrs after administration. The concentration of Lomefloxacin in the prostatic tissue and fluid is high enough to eradicate the majority of pathogens causing bacterial prostatitis.

4-Quinolones↗
PubMed1988

Development of a serum-free medium for in vitro immune responses by using beta-cyclodextrin. Demonstration of the requirements for polyamines.

A serum-free medium has been developed which is able to support primary antibody responses by cultured murine lymphocytes. This medium is based on RPMI 1640 that is supplemented with beta-cyclodextrin, insulin, transferrin, albumin, low density lipoprotein, putrescine and L-alanine as substitutes for fetal calf serum. Omission of anyone of these components resulted in a marked decrease of antibody responses. By employing the serum-free culture conditions, it was clearly demonstrated that polyamines such as putrescine, spermidine and spermine had positive effects on the development of antibody-forming cells. This serum-free medium supported the antibody response to sheep erythrocytes, trinitrophenyl (TNP)-Ficoll or TNP-lipopolysaccharide as efficiently as 10% fetal calf serum-containing medium. In addition, murine lymphocytes proliferated in response to an antigen or a mitogen equally well in these two types of medium.

Animals↗
PubMed1988

Structure of the ends of the coliphage N4 genome.

The coliphage N4 genome, a linear and double-stranded DNA of approximately 72,000 bases in length, has unique (non-permuted) direct terminal repeats of 390 to 440 base-pairs in length with 3' extensions. The very terminal sequences were determined by the Maxam-Gilbert method after 5' or 3' labeling, while sequences of internal fragments were determined by the dideoxy chain terminator method after cloning them onto M13 phage DNA. The left end of the N4 genome is relatively precise at its 5' terminus, while microheterogeneity of length exists at the 3'-terminal extensions. The predominant species had a 5 or 6 base 3' protruding sequence, 3' CATAA or 3' CATAAA. On the other hand, the right end is variable; there are at least six discrete ends differing from each other by approximately ten base-pairs and giving rise to the variability of the length of the terminal repeats. Each of the six discrete ends has a microheterogeneity of length, especially at the 3' termini. These properties of the terminal redundancy are discussed in conjunction with the mechanism whereby N4 DNA is replicated and processed.

Base Sequence↗
PubMed1988

Isolation of clones from T24 cells and test of their sensitivity to adriamycin.

Two single cell clones, CL3 and CL7, were developed from T24 cells. CL3 had abundant cytoplasmic granules, while CL7 did not have as much. CL3 and CL7 exhibited a modal number of chromosomes at 69 and 74, respectively. CL7 had a higher growth rate than CL3, as indicated by in vitro cell growth, plating efficiency, and growth of the tumors produced in nude mice. CL3 was slightly susceptible to adriamycin toxicity as compared to CL7.

Animals↗
PubMed1988

The effects of phosphorylation and dephosphorylation of brain myosin on its actin-activated Mg2+-ATPase and contractile activities.

Purified bovine brain myosin contained approximately 1 and 3 mol of protein-bound phosphate/mol myosin in the light chains and heavy chains, respectively. Large portions of this light chain- and heavy chain-bound phosphate (about 0.8 and 2.4 mol, respectively) were removed by incubation with a brain phosphoprotein phosphatase and potato acid phosphatase, respectively. Upon phosphorylation of the dephosphorylated brain myosin with myosin light chain kinase and casein kinase II, about 1.6 and 3.0 mol of phosphate was incorporated into the light chains and heavy chains, respectively, while much lower levels of phosphate were incorporated into the non-dephosphorylated brain myosin under the same conditions. The actin-activated Mg2+-ATPase activity of brain myosin rephosphorylated with myosin light chain kinase was about twice as high as that of dephosphorylated brain myosin (about 30 and 15 nmol phosphate/mg/min, respectively). On the other hand, whereas the rephosphorylated brain myosin superprecipitated rapidly with F-actin, the rate of superprecipitation of the dephosphorylated brain myosin was extremely low. Under appropriate conditions, a loose network of tiny superprecipitates, which formed initially throughout the solution, contracted to form eventually a large and dense particle. These results indicate that phosphorylation of the light chains of brain myosin is a prerequisite for the contraction of brain actomyosin. The role of phosphorylation of the heavy chains by casein kinase II remains to be elucidated.

Actins↗
PubMed1988

Mechanical stimulation and Fura-2 fluorescence in the hair bundle of dissociated hair cells of the chick.

1. Hair cells were dissociated from the inner ear of a chick and were loaded with the esterified form of the Ca2+-sensitive dye Fura-2. Fura-2 fluorescence was monitored by exciting at wavelengths of 340 and 380 nm in order to monitor intensity changes related to the intracellular Ca2+ concentration. The 340 and 380 nm fluorescence images and the ratio images between them (340 nm/380 nm) gave a good representation of the general shape of the hair cell and the hair bundle. 2. Fluorescence intensities were changed following depolarization of the membrane by high-K+ saline. The 340 nm fluorescence increased while that at 380 nm decreased. These fluorescence changes were probably due to changes in the intracellular Ca2+ concentration. 3. Fluorescence ratio images were observed while applying mechanical stimulation to the hair bundle. The intensity ratio was increased in the hair bundle and in the cell body by the depolarizing stimulation of displacing the hair bundle towards the taller stereocilium, while it was decreased by the hyperpolarizing stimulation of displacing the hair bundle towards the shorter stereocilium. 4. Manganese ions do not pass through the Ca2+ channel but carry transduction current and quench the fluorescence of Fura-2. Quenching was most prominent within the hair bundle when mechanical stimulation was applied by a puff of Mn2+ saline. 5. Smaller-amplitude mechanical stimulation was applied to the hair bundle by a sinusoidal stimulation. The fluorescence intensity ratio was increased about the hair bundle's insertion into the cuticular plate. 6. A belt-shaped depression area emerged in the fluorescence ratio image near the hair bundle's insertion into the cuticular plate when Mn2+ saline was puffed from a distant location, so that the displacement of the hair bundle was produced only by the fringe of the Mn2+ flow. 7. The ratio demonstrated a peak near the hair bundle's insertion into the cuticular plate in Mn2+-free saline exactly where a depression emerged in Mn2+ saline in the same hair cell. A sinusoidal stimulation was applied in both experiments. 8. It is concluded that the fluorescence intensity changes in the hair bundle are due to the influx of Ca2+ or Mn2+ ions through the mechano-electrical transduction channel. The intensity ratio changes observed near the hair bundle's insertion into the cuticular plate might indicate that this is the site of the mechano-electrical transduction.

Animals↗
PubMed1988

Amiloride blocks the mechano-electrical transduction channel of hair cells of the chick.

1. Effects of amiloride, applied extracellularly, on mechano-electrical transduction (MET) currents were investigated in dissociated hair cells of a chick with a whole-cell patch-electrode voltage clamp technique. Amiloride blocked the MET channel. The blocking was reversible and was both dose and voltage dependent and specific to the MET channel. The voltage-dependent Ca2+ channel of the basolateral membrane was not affected within the concentration range studied (up to 0.7 mM). 2. The limiting conductance of the MET at large negative membrane potentials decreased with increasing amiloride concentration. A dose-response relationship of the relative MET conductance (defined as the ratio of the MET channel conductance in the presence of amiloride to that without) at membrane potentials more negative than -50 mV had a Hill coefficient of 1, and a dissociation constant (KD) of 5 x 10(-5) M. 3. When amiloride was applied, the MET conductance increased as the membrane was depolarized, and the limiting value at positive membrane potentials was close to that of the control. The relationship between the relative MET conductance and the membrane potential was S-shaped. The conductance vs. voltage relationship was shifted in a positive direction along the voltage axis as the amiloride concentration was increased. 4. The blocking effect of amiloride on the MET channel was apparently independent of the mechanical gating of the channel. The voltage-independent block at or near the resting membrane potential and a voltage-dependent lifting of the block at depolarized membrane potentials could be explained quantitatively by a kinetic model which postulates one blocked state and two open states which have different amiloride affinities.

Action Potentials↗
PubMed1988

[Phase II study of 5-FU tablet in bladder tumor].

A phase II study of 5-FU tablet at a dose of 200 to 300 mg/day (b.i.d. or t.i.d.) for 28 patients with tumor of urinary bladder was undertaken by a cooperative study group consisting of 7 institutions including Okayama University. The clinical response rate in 25 evaluable cases was 20.0 (5/25) (CR: 2 cases, PR: 3 cases, MR: 4 cases, NC: 11 cases and PD: 5 cases). Efficacy rates of 5-FU tablet were higher in patients having smaller lesions or those who received no previous chemotherapy. Some adverse effects were observed in 6 of 27 cases (22.2%), all of which were gastrointestinal symptoms. Abnormal laboratory tests were seen in 18.5%, but all of these abnormalities were mild. 5-FU tablet administered to patients with tumor of urinary bladder was found to be highly distributed in tumor tissue. It is considered from the above results that 5-FU tablet is one of the useful agents for tumor of urinary bladder.

Administration, Oral↗
PubMed1988

[Clinical studies on the measurement of urinary tissue polypeptide antigen (TPA) levels using Prolifigen TPA kit "Daiichi"-II in urothelial cancers].

We have investigated the clinical significance of urinary tissue polypeptide antigen (TPA) as a tumor marker for urothelial cancers. Urinary TPA levels were determined by the immunoradiometric assay of Prolifigen TPA Kit "Daiichi"-II in 486 healthy controls and 1835 patients with various diseases including 526 with urothelial cancers and 140 with prostatic cancer. The mean value of urinary TPA was 199 +/- 213 (1SD)U/1 in 486 healthy controls. 95% of them having a level below 600 U/l. Therefore, 600 U/l was applied as a cut-off level. Positive rates of urothelial cancers and reactivated prostatic cancer were 57.6% (148 of 248 cases) and 45.5% (5 of 11 cases) respectively. On the other hand, the false positive rate of most urological benign diseases was only about 20% except for the acute stage of urinary tract infections and upper urinary tract stones with hydronephrosis. There was no significant difference in the positive rate between urinary TPA level and urinary cytology in urothelial cancers. The combination of both tests raised the positive rate to 73.1%. Therefore, urinary TPA may be useful in the monitoring of urothelial cancers, and the combination of urinary TPA and urinary cytology may increase the diagnostic accuracy.

Antigens, Neoplasm↗