Search PubMed⌕ Search

Biomedical subjects

S Kondo

Publications and source records attributed to S Kondo.

At least 1,063 records · Page 59Linked to original sources
PubMed1985

Calcium binding and conformation of regulatory light chains of smooth muscle myosin of scallop.

Calcium binding was studied with two regulatory light chains (RLC-a and RLC-b) of smooth muscle myosin of scallop. With the equilibrium dialysis method, the binding of 0.98 mol Ca2+ per mol of RLC-b was observed with a dissociation constant of 2.3 X 10(-5) M. Similar values for RLC-b, 1.9 X 10(-5) M, and RLC-a, 1.5 X 10(-5) M, were obtained by measuring the difference absorption spectrum induced by Ca2+. The difference molar absorption coefficient at 288 nm was 159 and 209 M-1 X cm-1 for RLC-a and RLC-b, respectively, while it was -34 M-1 X cm-1 for the regulatory light chain of striated muscle myosin of scallop (RLC-st). Proton NMR spectra of the three light chains were very similar to each other and were broader than those of other Ca2+ binding proteins, parvalbumin and calmodulin. The regulatory light chains may be more rigid than in these Ca2+ binding proteins. CD spectra were measured for the three light chains, and the estimated helix contents were 27, 29, and 24%, respectively, for RLC-a, RLC-b, and RLC-st. All these results in comparison with the primary structures led us to suppose that the polypeptide of regulatory light chains is folded in such a way that domain 4 becomes near to the calcium binding site of domain 1. The decrease in intact light chains on trypsin digestion was determined for the gel electrophoretic patterns. RLC-a was 6 times more susceptible to the tryptic digestion than RLC-b.(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acid Sequence↗
PubMed1985

Effects of autonomic drugs on in vivo recording of electromyograms of canine renal pelvis and ureter.

The effects of the autonomic drugs (noradrenaline, isoproterenol and acetylcholine) and the urine volume change on the pacemaker of ureteral peristalsis were studied by our new method of the in vivo recording of electromyograms (EMGs) of canine renal pelvis. The EMGs of the pelvicalyceal region showed a two phasic slow-rising potential of amplitude of 20 microV and discharge interval of 5 s and was different from propagated waves and therefore considered to be the pacemaker potentials. In the diuretic state the pacemaker potentials kept a constant discharge interval. On the contrary, the discharge interval of the ureter EMG became shorter and finally corresponded to the pacemaker EMG one to one. These results suggest that the urine transport in the diuretic state is controlled by the change of efficiency of the peristaltic propagation and not by the changes of the discharge of the pacemaker itself. Noradrenaline promoted the ureteral peristalsis and isoproterenol inhibited the ureteral peristalsis. These two drugs had no effects on the pacemaker potentials. Acetylcholine had a great variety of the effects on the ureter EMG and the pacemaker EMG separately. These results suggest that the pacemaker of the ureteral peristalsis is controlled under the influence of the parasympathetic system and the ureter is controlled under the influence of both the sympathetic and parasympathetic system.

Acetylcholine↗
PubMed1985

[Radiographical changes in the elbow joints of chainsaw operators].

The purpose of this study is to clarify the relation between the labor history of chainsaw operators and changes in their elbow joints. Osteophytic and degenerative changes on X-ray films of the elbow joints were compared quantitatively between chainsaw operators and a control group of age-matched road maintenance workers. Subjects were divided into three groups according to length of chainsaw use. Although no statistically significant differences were found among the three groups, radiographical examination showed significant changes (p less than 0.05) in the subjects as compared with the controls. Because of other labor factors that were not considered, the existence of a dose-response relationship between elbow damage and length of chainsaw use cannot be confirmed from this study, but such a relationship is suggested.

Age Factors↗
PubMed1985

Relationship between pelviureteral peristaltic frequency and urine flow change evoked by autonomic drug administration.

Parallel recording of renal pelvic pressure, ureteral electromyogram and urine volume was carried out in dogs given intravenous injections of noradrenaline, isoproterenol or acetylcholine. With noradrenaline, an increase in urine volume was observed coincidentally with an elevation of renal pelvic pressure and an increase in frequency of ureteral peristalsis. In response to isoproterenol, the urine volume diminished in harmony with flattening of pelvic pressure waves and the disappearance of ureteral peristalsis. Conversely, ureteral peristalsis increased in frequency immediately after the administration of acetylcholine, while the urine volume diminished.

Acetylcholine↗
PubMed1985

Changes in the ureteral peristaltic rate and the bolus volume in gradual and rapid urinary flow increase.

The electromyogram and bolus volume of ureteral peristalsis were measured during gradual and rapid urinary flow increase, using 16 mongrel dogs. When the urine flow was increased rapidly by administration of diuretics, the ureteral peristaltic rate always increased first, then the urine bolus volume increased and finally the ureter became a urinary column without forming the urine bolus. When the urine flow was increased gradually by intravenous drip infusion of saline solution, the ureteral peristaltic rate and urine bolus volume did not always increase in spite of urinary flow increase. The peristaltic rate and bolus volume helped each other for effective urinary transport, as both of them not only always increase but also one of them occasionally decreased.

Animals↗
PubMed1985

Effects of dobutamine on cyclic AMP content in canine upper urinary tract tissue.

There was no regional difference in tissue cAMP content throughout the upper urinary tract specimens obtained from dogs immobilized by pancuronium bromide (0.1 mg/kg, i.v.). The cAMP content was increased in all regions examined 5 min after administration of dobutamine (1 mg/kg, i.v.) and pancuronium bromide. The increase was much higher in the pelvicalyceal region than in the other upper urinary tract tissue. The responsiveness of the pelvicalyceal region where pacemaker cells for ureteral peristalsis exist is considered to be higher than that in the other upper urinary tract tissue in respect to dobutamine-induced cAMP increase.

Animals↗
PubMed1985

[Automated autoradiographic grain counting of DNA repair in cultured human fibroblasts after ultraviolet irradiation].

Measurement of autoradiographic grains produced by the decay of incorporated radioisotopes is often used for a quantitative assay of the rate of DNA replication and DNA repair in cells or tissues. However, visual grain counting by microscopic observation is time-consuming and tedious process. Recently, Kraemer et al. reported that automated measurement of grains in cultured human cells may be facilitated by using appropriate grain counting instruments. Under their experimental conditions using Kodak NTB-3 emulsion, instrument-determined grain number per nucleus was proportional to visual counts up to 30 grains, and then leveled off at much larger visual counts. The saturation phenomenon was due to counting-loss by the instrument caused by overlapping of neighboring grains. To prevent the counting-loss, we have used in the present study Japanese Sakura NR-M2 emulsion which is less sensitive to radiation exposure than Kodak NTB-3, thereby yielding smaller size of grains per radioactive decay. Samples were prepared from cultured skin fibroblasts derived from normal individuals and xeroderma pigmentosum (XP) patients defective in DNA repair. These cells were irradiated with 254 nm UV incubated for 3 h with culture medium containing 3H-thymidine, and autoradiograms were made by dipping in Sakura NR-M2 emulsion. The number of grains as well as grain surface area per nucleus was measured by using ARTEK CYTO TALLY MODEL 900 counting instrument, and compared with visual counts. The results showed that, under our optimum condition, the instrument-determined number of grains was directly proportional to visual counts, at least up to 150 grains per nucleus, with a correlation coefficient of 0.971.(ABSTRACT TRUNCATED AT 250 WORDS)

Autoradiography↗