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Biomedical subjects

F Hayashi

Publications and source records attributed to F Hayashi.

At least 163 records · Page 9Linked to original sources
PubMed1987

Phosphatidylinositol stimulates phosphorylation of protein components I and II in rod outer segments of frog photoreceptors.

We studied the effect of phosphoinositides on the phosphorylation of endogenous proteins in the soluble fraction of the frog photoreceptor rod outer segments (ROS). Phosphatidylinositol (PI) stimulated the phosphorylation of two low molecular weight proteins, components I and II (12 and 11 kDa) which are known to be the preferential substrates of the cyclic GMP (cGMP)-dependent protein kinase in the ROS. Polyphosphoinositides (PPI) specifically inhibited the PI-dependent phosphorylation of these two components. On the other hand, PPI stimulated the phosphorylation of 38, 48 and 52 kDa proteins in the absence of PI. These data suggest that PI and PPI may function in the ROS by regulating the phosphorylation of some enzymes or regulator proteins in the transduction mechanism in the ROS.

Adenosine Triphosphate↗
PubMed1987

Preparation of highly concentrated super-hot [gamma-32P]ATP using small-scale ion-exchange chromatography.

In order to obtain a highly concentrated, pure and super-hot [gamma-32P]ATP, we improved the purification method of super-hot [gamma-32P]ATP which was synthesized by the method of Johnson and Walseth (1979). The super-hot [gamma-32P]ATP was synthesized in a relatively large volume (2 ml) of reaction mixture and purified using semi-micro scale anion exchange chromatography (Dowex 1 X 2, 60-70 microliters column volume). In combination with washing the reaction product with certain organic solvents, this chromatography technique makes it possible to obtain a highly concentrated and pure super-hot [gamma-32P]ATP (approx. 7,000 Ci/mmol; 20-30 mCi/ml) from [32P]Pi of any commercial source in a good yield.

Adenosine Triphosphate↗
PubMed1986

A p60v-src-related tyrosine kinase in the acetylcholine receptor-rich membranes of Narke japonica: association and dissociation of phosphatidylinositol kinase activity.

We have isolated a tyrosine-specific protein kinase from the acetylcholine receptor (AChR)-rich membranes of the electric ray Narke japonica. The enzyme is immunologically related to p60v-src, the product of the transforming gene of Rous sarcoma virus. A substantial phosphatidylinositol (PI) kinase activity was associated with this enzyme when it was purified through tyrosine-agarose affinity chromatography used previously for the purification of p60v-src. However, by subsequent chromatography on casein-agarose, most of the associated PI kinase activity was separated from the tyrosine kinase activity. The results suggest that the tyrosine-specific protein kinase in the AChR-rich membranes of N. japonica has no intrinsic PI kinase activity.

Animals↗
PubMed1986

[Antibody-dependent cell-mediated cytotoxicity (ADCC) in gastric and colorectal cancer].

Antibody-dependent cell-mediated cytotoxicity (ADCC) was studied in 20 gastric and colorectal cancer patients by the microtest plate assay with sheep erythrocytes as the target cells. In cancer patients (with both good and poor prognosis), the peripheral K-cell level showed a significant decrease as compared with that of normal subjects. No meaningful difference of the K-cell level was observed between the good and poor prognosis groups. For the purpose of the follow-up of cancer patients, the determination of the K-cell level was useful only when time-lapse examination were performed in the same case.

Adult↗
PubMed1985

Light-mediated breakdown of phosphatidylinositol-4,5-bisphosphate in isolated rod outer segments of frog photoreceptor.

When isolated frog (Rana catesbeiana) rod outer segment (ROS) fragments were incubated with [gamma-32P]ATP in the dark, only two of phospholipids, i.e., phosphatidylinositol-4-phosphate (DPI) and phosphatidic acid (PA) incorporated 32P. Upon addition of DPI (100 microM), considerable amount of 32P was incorporated into phosphatidylinositol-4,5-bisphosphate (TPI) as well as DPI and PA. Exposure of the ROS membranes to 5 sec flash of light resulted in approx. 20% decrease in the labeled TPI, while no significant effect was observed on DPI and PA. It was also observed that Ca2+ markedly accelerated the production of PA in the dark, while it reduced the 32P-incorporation into TPI. These results suggest that there is light- and/or Ca2+-dependent TPI-specific phospholipase C in ROS of vertebrate photoreceptors.

Animals↗
PubMed1985

Calcium- and calmodulin-dependent phosphorylation of diphosphoinositide in acetylcholine receptor-rich membranes from electroplax of Narke japonica.

The phosphorylation of phosphoinositides in the acetylcholine receptor (AChR)-rich membranes from the electroplax of the electric fish Narke japonica has been examined. When the AChR-rich membranes were incubated with [gamma-32P]ATP, 32P was incorporated into only two inositol phospholipids, i.e., tri- and diphosphoinositide (TPI and DPI). Even after the alkali treatment of the membrane, AChR-rich membranes still showed a considerable DPI kinase activity upon addition of exogenous DPI. It is likely that the 32P-incorporation into these lipids was realized by the membrane-bound DPI kinase and phosphatidyl inositol (PI) kinase. Such a membrane-bound DPI kinase was activated by Ca2+ (greater than 10(-6) M), whereas the PI kinase appeared to be inhibited by Ca2+. The effect of Ca2+ on the DPI phosphorylation was further enhanced by the addition of ubiquitous Ca2+-dependent regulator protein calmodulin. Calmodulin antagonists such as chlorpromazine (CPZ), trifluoperazine (TFP), and N-(6-aminohexyl)-5-chloro-1-naphthalenesulfonamide (W-7) inhibited the phosphorylation of DPI in the AChR-rich membranes. It is suggested that the small pool of TPI in the plasma membrane is replenished by such Ca2+- and calmodulin-dependent DPI kinase responding to the change in the intracellular Ca2+ level.

Animals↗
PubMed1985

[Preclinical and clinical studies on aztreonam in the field of obstetrics and gynecology].

Penetration of aztreonam (AZT) into the uterus and the adnexal tissues and usefulness and safety of AZT for obstetric and gynecologic infections were studied with the following results. By one shot intravenous injection of AZT 1 g, the uterus and the adnexal tissues showed favorable penetration with Cmax 27.0-48.5 micrograms/g, AUC 29.4-84.9 micrograms X hr/g and Tmax 0.10-0.44 hours. MIC50, MIC80 and MIC90 of AZT for Gram-negative bacteria measured prior to administration were very low being 0.10 micrograms/ml, 0.20 micrograms/ml and 1.56 micrograms/ml, respectively. Clinical effect of AZT for 30 infection cases in obstetrics and gynecology was evaluated according to an overall efficacy criteria resulting in "good" for all the cases. With regard to microbiological effect, 90.9% of the pathogens isolated prior to the administration were eliminated by AZT. During and after the administration of AZT, side effect due seemingly to AZT was not observed in subjective and objective symptoms and laboratory values.

Adult↗
PubMed1985

[Postoperative cell-mediated immunity in gastric cancer patients--with special reference to the effects of immunotherapy].

The cell-mediated immunity of gastric cancer subjects was investigated during the postoperative follow-up period from three to 12 months after surgery. The lymphocyte blastogenesis, the T cell count, the lymphocyte count and the lymphocyte percentage were significantly decreased in groups of experimental laparotomy and noncurative gastrectomy, compared with that of nonrecurrent cases after curative gastrectomy. The effects of the administration of immunopotentiators, the streptococcal preparation OK-432, and the protein-bound polysaccharide PSK, were studied in groups of curative gastrectomy. The lymphocyte blastogenesis, the T cell count and the lymphocyte count were slightly elevated in the OK-432 group.

Biological Products↗
PubMed1985

[Fundamental and clinical studies on cefpimizole in the field of obstetrics and gynecology].

Cefpimizole (AC-1370) was studied for its transference into adnexa uteri and uterine tissues as well as for its effects and safety on gynecological infections. The results obtained are as follows: Peak levels of AC-1370 were obtained in the antecubital vein and uterine artery at 10 minutes, in the tissues of adnexa uteri and uteri about 30 minutes after one shot intravenous injection of AC-1370 1 g, and relatively high concentrations were maintained for several hours. In the treatment of 30 cases of gynecological infections, the clinical efficacy of AC-1370 was assessed as effective in all cases. As for the bacteriological effects of AC-1370, 77.6% of isolated organisms were eradicated and 90% of all cases were effective. Side effects and abnormal laboratory findings due to AC-1370 were not observed during and after administration.

Adult↗
PubMed1985

[Clinical trial of cefpiramide in the gynecological field].

Cefpiramide (CPM) was administrated intramuscularly to 27 cases of gynecological infections to evaluate its clinical efficacy and safety and the following results wee obtained. CPM was effective to all the cases of gynecological infections, and excellent was seen in 14 cases and good was seen in 13 cases. CPM eliminated 75% of clinical isolates. Laboratory tests were performed to blood samples and functions of liver and kidney before and after CPM treatment. Elevation of GPT was observed in 2 cases but required no treatment.

Adolescent↗
PubMed1984

Photochemically induced dynamic nuclear polarization study on microsomal NADPH-cytochrome P-450 reductase.

Sedimentation equilibrium experiments with NADPH-cytochrome P-450 reductase showed that increasing 1-O-n-octyl-beta-D-glucopyranoside levels promoted disaggregation of the flavoprotein. The reductase was monomeric at a molar ratio of detergent to protein above 10(3). Addition of N3-carboxymethyllumiflavin to the flavoprotein in the presence of 1-O-n-octyl-beta-D-glucopyranoside results in photochemically induced dynamic nuclear polarization (CIDNP) signals in the aromatic region. The CIDNP spectrum of the holoprotein shows sharp resonances due to histidine residues. On removal of FMN from the protein, CIDNP signals originating from a tyrosine residue appeared, suggesting that the tyrosine residue is exposed to solvent after the depletion of FMN. However, this tyrosine residue appears to become inaccessible to the external dye after full incubation of FMN-depleted reductase with FMN. This suggests that the tyrosine residue could be located in the vicinity of the FMN-binding domain which constitutes the active center of the reductase.

Animals↗
PubMed1984

Ventilatory and heart rate responses to hypoxia in well-trained judo athletes.

Twenty-four active judo athletes were examined by an isocapnic progressive hypoxia test. The results of ventilatory and heart rate responses to hypoxia were analyzed by the hyperbolic equations, VE = VO + AVE/(PETO2 - CVE) and HR = HRO + AHR/(PETO2 - CHR), respectively, where VE and HR are observed ventilation and heart rate, VO and HRO the horizontal asymptote in ventilation and heart rate for infinite end-tidal PO2 (PETO2), AVE and AHR the slope constant indicating the magnitude of hypoxic sensitivity, and CVE and CHR the vertical asymptote in PETO2 for infinite ventilation and heart rate. AVE was further re-calculated after VE was normalized for a 70 kg body mass, using an allometric coefficient, and was defined as AVEN. 1) AVE and AVEN significantly increased with increasing body weight (BW) as has been reported previously, but no such correlation was found between AHR and BW. 2) VO2 at rest was found to be positively correlated with AVE and AVEN but not with AHR. 3) The relationship between AVE and AHR was not significant. Thus, the characteristic feature seen in hypoxic ventilatory activity was not accompanied by a similar trend in heart rate response.

Adolescent↗
PubMed1984

Augmentation of CO2 drives by chlormadinone acetate, a synthetic progesterone.

We studied 10 male subjects who were administered chlormadinone acetate (CMA), a potent synthetic progesterone, to clarify the physiological basis of its respiratory effects. Arterial blood gas tension, resting ventilation, and respiratory drive assessed by ventilatory and occlusion pressure response to CO2 with and without inspiratory flow-resistive loading were measured before and 4 wk after CMA administration. In all subjects, arterial PCO2 decreased significantly by 5.7 +/- 0.6 (SE) Torr with an increase in minute ventilation by 1.8 +/- 0.6 l X min-1, whereas no significant changes were seen in O2 uptake. During unloaded conditions, both slopes of occlusion pressure and ventilatory response to CO2 increased, being statistically significant in the former but showing nonsignificant trends in the latter. Furthermore, inspiratory flow-resistive loading (16 cmH2O X l(-1) X s) increased both slopes more markedly after CMA. The magnitudes of load compensation, assessed by the ratio of loaded to unloaded slope of the occlusion pressure response curve, were increased significantly. We concluded CMA is a potent respiratory stimulant that increases the CO2 chemosensitivity and neuromechanical drives in the load-compensation mechanism.

Aged↗