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Biomedical subjects

F Ito

Publications and source records attributed to F Ito.

At least 271 records · Page 15Linked to original sources
PubMed1980

Site of origin of calcium spike in frog muscle spindle.

In order to define the site of origin of the calcium spike along the sensory nerve terminal of the frog muscle spindle, changes in the amplitude of the spikes during long-lasting polarizations of the nerve terminal were compared with those of full-sized and abortive spikes which occurred spontaneously. The amplitude of the calcium spikes superimposed on a spindle potential was not modifiable by application of polarizing currents of 6 nA or less, as well as that of the abortive spikes; while the amplitude of the full-sized spikes depended upon the polarizations. These results suggest that the calcium spikes may initiate along the non-myelinated filaments, as in the abortive spike, in contrast with the full-sized spikes to generate at the terminal node of the myelinated axon.

Afferent Pathways↗
PubMed1980

Rectangular fluctuations in potential of the afferent nerve terminal during depolarization in the frog muscle spindle.

Rectangular fluctuations in potential are observed during application of depolarizing currents from 1.5 to 6.3 nA across the air-gap on which the myelinated segment just outside the capsule in isolated muscle spindles is laid. The rapid decay in the potential is often triggered by after-hyperpolarization following afferent discharges. The fluctuations are not affected by TTX or in Na+-free solution but are reversibly blocked by 100 microM quinine. The results suggest that the fluctuations may be due to [Ca2+]i-activated Pk.

Action Potentials↗
PubMed1980

A protein required for the initiation of DNA synthesis by RNA polymerase.

RNA polymerase of Shigella sonnei rif purified through DEAE-Sephadex A-50 could not initiate the synthesis of DNA using phage fd DNA as a template. A protein which could complement the polymerase to initiate the synthesis of DNA was recovered from the DEAE-Sephadex A-50 column separately from the RNA polymerase. There is apparently a protein which is required to synthesize a primer RNA for the synthesis of DNA other than the components of RNA polymerase holoenzyme of Shigella sonnei rif. The protein seems to be specifically required for the initiation of DNA synthesis and to have little effect on the synthesis of RNA.

Bacterial Proteins↗
PubMed1979

Alteration of hexosaminidase isozymes in human renal carcinoma.

The activity and isozyme patterns of hexosaminidase in human renal carcinoma were studied in comparison with those of normal kidney. Hexosaminidase in extracts from normal kidney and renal carcinoma tissue could be separated into two major forms [hexosaminidase A (Hex A) and hexosaminidase B (Hex B)] by Cellogel electrophoresis or by diethylaminoethyl cellulose column chromatography. All of 10 renal carcinoma tissues showed a low activity ratio of Hex A to Hex B, as compared with the ratio in normal kidney; the ratio in renal carcinoma tissue was between 0.61 and 2.21 (mean, 1.30), while that in normal kidney was between 2.50 and 4.52 (mean, 3.46). Hexosaminidase activity and the ratio of Hex A to Hex B in renal carcinoma tissue were independent of the cell type and the differentiation grade of carcinoma tissue. Hex A and Hex B of renal carcinoma tissue differed from each other in physicochemical properties such as pH dependence of enzyme activity, thermostability, and Km's for two synthetic substrates, but each isozyme maintained its same physicochemical properties whether from normal or from carcinoma tissue. The isozyme patterns of cultured renal carcinoma cells and placenta were similar to those of the carcinoma tissue. The results presented here indicate that hexosaminidase isozymes in renal carcinoma tissue express at least oncoplacental patterns.

Acetylglucosaminidase↗
PubMed1978

[Effects of local vibration exposure on the cerebral blood flow--on the relation of brain and finger blood flow to vibration frequencies (author's transl)].

The healthy young men aged from 18 to 26 years were examined whether some vibrational stimuli may affect the vasoreaction in the brain and in a finger. The vasoreaction was observed on each subject after the exposure to vibration of frequencies 32, 64, 140 and 250 Hz with acceleration level at 98 m/sec2 and compression force at the vibrating grip of 5 kg, while in the control state the vibration was exactly the same except the vibrational stimuli. Vasodilation and vasoconstriction were observed when low frequency and high frequency vibrational stimuli were given respectively. Vasoreactive pattern of the brain was almost the same as that of the finger.

Adolescent↗