Biomedical subjects

K Fukuda

Publications and source records attributed to K Fukuda.

28 records · Page 2Linked to original sources

PubMed1978

Studies of water in biological systems by a pulsed NMR method. 1. Flow profile in a cylindrical tube.

Pulsed NMR experiments on water flowing through cylindrical tubes are discussed. Spin echo signals of proton nuclear spins in water molecules were detected RF (radio frequency) phase-sensitively in static magnetic field gradients which were superposed on a main magnetic field. Both the intensity and the RF phase of the spin echo signal depended upon the flow pattern. It is shown that the velocity distribution function was driven from the magnetic field gradient dependence of spin echo signals. Velocity distributions (or velocity profiles) of the fluid in a uniform cylindrical tube have been measured from the spin echo signals. The data on the flow behind a stenosis were widely different from the data on laminar flows.

Magnetic Resonance Spectroscopy↗

PubMed1977

Chromatin ultrastructure of lower vertebrates.

Meiotic and mitotic chromosomes from amphibians and snakes were studied by electron microscopy. By using water spreading, preceded by a mild NaCl pretreatment, we showed: 1. 'Beads on a string' arrangement of the chromatin fibres; 2. The presence of loops at pachytene chromomeres as well as during metaphase of both mitosis and first meiosis; 3. Transcriptional activity for non-ribosomal RNA on peripheral loops during the middle pachytene.

Animals↗

PubMed1977

Pregnancy and delivery in penicillamine treated patients with Wilson's disease.

Pregnancy and delivery of two patients with Wilson's disease are reported. Case 1 was a 20-year-old housewife who had been taking D-penicillamine fore more than 10 years and had remained asymptomatic except an episode of dissociative reaction. She apparently survived longer than any of her three sisters who died of the same disease. She discontinued the use of D-penicillamine by herself when she was at the 22nd week of pregnancy. Case 2 was a 32-year-old housewife who developed an episode of mental disorder of short circuit reaction type with mild neurological symptoms and Kayser-Fleischer rings after the prolonged interval of medication since the first pregnancy and delivery. Three months after the complete recovery of neuropsychiatric symptoms she was at the 12th week of pregnancy and withheld penicillamine from herself. During the pregnancy they had not revealed any exacerbation in terms of clinical and laboratory findings. Each of them was delivered of a healthy baby. Although the pregnancy and delivery of both patients were successful, the authors recommended that they should not prolong the interval of medication to protect themselves against the onset or relapse of the illness.

Adult↗

PubMed1976

Six years of experience with retrograde biopsy of intraureteral carcinoma using the Dormia stone basket.

To confirm the cause of a small defect of the ureter and to determine preoperatively the histological grade of ureteral carcinoma a new technique of intraureteral biopsy was attempted with a Dormia stone basket. Of 8 biopsies performed on 7 patients with ureteral or pelvioureteral carcinoma only 1 failed to produce a fragment of tissue. Histological diagnosis was made in each of the 7 patients and histological grading in 5. Four patients with non-malignant defects of the lower ureter also were biopsied with this technique to ascertain the feasibility of this biopsy on minimal filling defects. In each patient a tiny piece of tissue was removed. Histological diagnosis could be made in 3 cases.

Adult↗

PubMed1976

A study of the native-denatured (N in equilibrium with D) transition in lysozyme. II. Kinetic analysis of protease digestion.

Kinetic analyses of the protease digestion of several chemical derivatives of lysozyme [EC 3.2.1.17] showed that only the D(denatured) state of the protein is digested and that the reaction velocity is proportional to the equilibrium constant (KD) of the N in equilibrium with D transition of the protein. Alteration of the net charge of lysozyme by acetylation caused a shift of the N in equilibrium with D transition to the right (ten-fold increase in KD compared to that of native enzyme). Both the formation of a lysozyme-inhibitor complex and the introduction of a covalent bond in the lysozyme molecule restricted the transition. The magnitude of the N in equilibrium with D transition is related to the susceptibility of lysozyme to protease digestion and it is estimated that the N in equilibrium with D transition in proteins is generally important in the intracellular catabolism of proteins.

Acetylation↗

PubMed1976