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Biomedical subjects

K Ono

Publications and source records attributed to K Ono.

At least 793 records · Page 44Linked to original sources
PubMed1991

Potentiation by cyclic GMP of beta-adrenergic effect on Ca2+ current in guinea-pig ventricular cells.

1. Effects of cyclic GMP on L-type Ca2+ current (ICa) were investigated in myocytes isolated from guinea-pig ventricles using the patch clamp method in the whole-cell configuration combined with intracellular perfusion. 2. When ICa was increased by bath application of isoprenaline (0.001-0.1 microM) or forskolin (0.5-1 microM), or by intracellular dialysis with cyclic AMP (50-100 microM), dialysis with 10 microM-cyclic GMP resulted in an additional stimulation of ICa. Without these pre-treatments, cyclic GMP (1-100 microM) had no effect on the basal ICa. 5'-GMP was without effect. 3. The stimulatory effect of cyclic GMP was observed at concentrations higher than 0.1 microM with a maximum at around 10 microM in the pipette. The dose-response relation between isoprenaline and ICa was shifted to the left by (10 microM) cyclic GMP; the half-maximum isoprenaline concentration shifted from 16 to 4.6 nM. 4. The increase of ICa on dialysing 50 microM-cyclic AMP varied from cell to cell, probably due to a difference in phosphodiesterase activity. The cells responding weakly to cyclic AMP showed a greater response to cyclic GMP, and vice versa. In cells dialysed with hydrolysis-resistant derivatives (10-50 microM-8-(4-chlorophenylthio)-cyclic AMP or 50 microM-8-bromo-cyclic AMP), additional dialysis with cyclic GMP failed to modify ICa. Dialysis with cyclic GMP abolished the stimulatory effect of milrinone, a specific inhibitor of cyclic GMP-inhibited phosphodiesterase. These findings suggested that inhibition of cyclic GMP-sensitive phosphodiesterase was responsible for the stimulatory effect of cyclic GMP. 5. In the presence of isoprenaline, direct application of an active fragment of cyclic GMP-dependent protein kinase (PKG) failed to modify ICa in most cells. Activation of native PKG by intracellular dialysis with 8-bromo-cyclic GMP, or higher concentrations of cyclic GMP (100-1000 microM), depressed ICa in about 25% of the cells. Furthermore, dialysis of cyclic GMP reversed the increase of ICa by the non-specific phosphodiesterase inhibitor, 3-isobutyl-1-methyl-xanthine (IBMX). These findings suggested the presence of antagonistic mechanisms of cyclic GMP, which are independent from the above synergistic action. PKG may be involved in this antagonistic effect.

Animals↗
PubMed1991

[A case of smoldering adult T-cell leukemia complicated by various pulmonary infections].

A 46-year-old man was admitted to Oita Medical College Hospital on October 16, 1987, because of cough and sputum. Chest X-ray and chest CT films showed diffuse reticulonodular shadow. The specimens obtained by transbronchial lung biopsy revealed cysts of pneumocystis carinii. Abnormal lymphocytes with lobulated nuclei were found 2-7% of peripheral leucocytes. The anti HTLV-I antibody was positive. According to these data, we diagnosed the patient as smoldering adult T cell leukemia with pneumocystis carinii pneumonia. The abnormal shadow on chest X-ray disappeared after SMX-TMP and pentamidine treatment. After about 1 year, he was again admitted for high fever. Chest X-ray showed infiltration with cavity in right upper lobe. Streptococcus pneumoniae was isolated from the sputum. The infiltration shadow on chest X-ray disappeared after antibiotics treatment. However, multiple nodular shadow appeared on the chest X-ray and ATL cell infiltration was found in the specimens of transbronchial lung biopsy. ATL cells in peripheral blood also increased and serum LDH and Calcium levels were markedly high. According to these data, we diagnosed the patient as having a ATL crisis. Although chemotherapy for ATL was started, the ATL, cell infiltration shadow on the chest X-ray enlarged, and bilateral diffuse patchy shadows was appeared on the chest X-ray. He died of respiratory failure on April 26, 1989. Cytomegalovirus pneumonia and ATL cell infiltration were revealed by necropsy.

Anemia, Refractory, with Excess of Blasts↗
PubMed1991

[A study on hepatic dysfunction associated with rubella infection].

We had 11 patients with rubella infection accompanied by hepatic dysfunction from 1979 through 1989. The elevations of sGOT were moderate, but sLDH levels were high. Extra hepatic manifestations were suspected by analysis of LDH isozymes. In 9 out of 11 patients, the sGPT levels returned to normal within 8 weeks. But prolonged courses of abnormal transaminase levels were observed in 2 patients. One was accompanied by underlying chronic hepatitis type non-A, non-B, and the other was supposed to have a prolonged rubella infection. Liver biopsy specimen taken from one patient in the acute phase demonstrated a non-specific reactive hepatitis. These observations suggest that rubella infection should be taken into consideration in making the diagnosis of sporadic hepatitis type non-A, non-B.

Adult↗
PubMed1991

Nerve root avulsion of birth palsy: comparison of myelography with CT myelography and somatosensory evoked potential.

Findings at myelography and computed tomographic (CT) myelography were reviewed in 21 patients (22 limbs) with birth palsy; nerve root shadows were the focus of this study. Myelography demonstrated 51 completely avulsed roots (78%) and 14 incompletely avulsed roots (22%). A traumatic meningocele was detected at 38 roots on myelograms and 51 roots on CT myelograms. Thirteen avulsed roots (eight completely and five incompletely avulsed roots) (20%) were not associated with a meningocele. In nine patients who underwent brachial plexus exploration, myelographic findings were compared with root somatosensory evoked potential (SEP). SEP was not induced at 22 of 25 completely avulsed roots and was induced at all seven incompletely avulsed roots. Myelography and SEP were consistent in 29 of 32 roots (91%). It is concluded that myelography is indispensable for preoperative evaluation of cervical nerve root avulsion of birth palsy, because CT myelography is not sensitive to nerve root avulsion without a traumatic meningocele, and SEP cannot enable one to discriminate incomplete avulsion from intact roots.

Brachial Plexus↗
PubMed1991

Neuropeptide-Y-immunoreactive chief cells in the carotid body of young rats.

The immunolight- and electron-microscopic study revealed neuropeptide Y (NPY) immunoreactivity in the chief cells and a few nerve fibers of the carotid body of young rats. NPY-immunoreactive chief cells were often seen as a single cell or a group of a few chief cells in the carotid body of young rats. The immunoreaction deposits were mainly seen in the dense-cored vesicles and diffusely in the cytoplasm of the chief cells. These findings suggest that NPY may be stored in the core of granules of the chief cells of the carotid body in young rats.

Animals↗
PubMed1991

Exocytosis in pheochromocytoma cells after exposure to a high concentration of potassium.

An electron-microscopic study revealed exocytosis of electron-dense granules in rat pheochromocytoma (PC12) cells after 1-min exposure to a high concentration of potassium medium. Numerous omega profiles indicative of the exocytosis were seen in the surface membrane of the PC12 cells. Most omega profiles showed clear or did not contain the granule contents. Sometimes, the granular, flocculent or dense materials were seen within the omega profiles that were exposed directly to the extracellular medium. Moreover, noncoated or coated omega profiles were observed. Coated vesicles were also visible under the surface membrane. The present study suggests that PC12 cells retain the exocytotic release mechanism for catecholamines.

Animals↗
PubMed1991

Complete seroconversion by low-dose intradermal injection of recombinant hepatitis B vaccine in hemodialysis patients.

The present study was undertaken to find out if the seroconversion rate of hemodialysis (HD) patients was enhanced by the intradermal (i.d.) inoculation of recombinant hepatitis B (HB) vaccine. Thirty-five HBs-Ag, HBs-Ab and HBc-Ag, HBc-Ab negative HD patients were divided into three groups: 14 patients in group I received 5 micrograms HBs Ag i.d. every 2 weeks, 13 patients in group II were given 2.5 micrograms HBs vaccine i.d. every 2 weeks, 5 times, then every week. The remaining 8 patients in group III were immunised with 10 micrograms HBs Ag every 4 weeks 5 times intramuscularly (i.m.), then 5 micrograms i.d., every 2 weeks until complete seroconversion. Antibody response to i.m. injection was poor and only 37.5% of patients developed anti-HBs at a titer of 10 mIU/ml or more at 16 weeks after the start of immunisation. However, this poor response was improved by i.d. injection. The time of seroconversion was significantly earlier and the rate of response was higher in group I. The poor response in group II was markedly improved by doubling the inoculation rate. Overall, 100% of seroconversion was finally obtained by multiple i.d. immunisation. However, the anti-HBs titers were lower in all patients and declined in some patients after the immunisation was stopped. The last seroconverted patient in each group lost protective antibody levels at the 39th week. These patients became antibody positive again at the 52nd week with a booster dose. We feel that the i.d. route remains a useful and cheaper method of obtaining prophylaxis against HBs in high-risk HD patients but it would seem to be prudent to monitor these patients serially to assess the persistence of anti-HBs in the serum.

Adult↗
PubMed1991

Selective synthesis of 2,4-bis(O-methoxypolyethylene glycol)-6-chloro-s-triazine as a protein modifier.

2,4-Bis(O-methoxypolyethylene glycol)-6-chloro-s-triazine, a protein modifier with two polyethylene glycol chains (activated PEG2) was synthesized from monomethoxypolyethylene glycol and cyanuric chloride using zinc oxide as a catalyst by the improved method of a previous study (Matsushima et al., Chem. Lett. 7, 773, 1980). The product was identified as activated PEG2 without contamination of by-products with chromatographic and structural analysis.

Catalysis↗
PubMed1991

Effects of augmenting cardiac contractility, preload, and heart rate on cardiac output during enflurane anesthesia.

Changes in cardiac output in response to augmenting cardiac contractility, preload, and heart rate during enflurane anesthesia were examined in 12 open-chested dogs. Cardiac contractility was assessed by the slope of the end-systolic pressure-volume relation (Emax). Dobutamine (3, 6, and 9 micrograms.kg-1.min-1) was administered to augment cardiac contractility. Autologous blood (5.0 and 10 mL/kg) was infused to increase preload. Atrial pacing was used to increase the heart rate by about 30%. Cardiac output decreased from 96 +/- 4 (0% enflurane) (mean +/- SE) to 73 +/- 5 (1.7% enflurane) and to 46 +/- 7 mL.kg-1.min-1 (3.4% enflurane), concomitantly with decreases in Emax from 6.0 +/- 1.2 (0% enflurane) to 4.5 +/- 1.2 (1.7% enflurane) and to 2.5 +/- 0.5 mm Hg/mL (3.4% enflurane). Dobutamine (3, 6, and 9 micrograms.kg-1.min-1) increased Emax from 69% +/- 7% (compared to 0% enflurane with no dobutamine) to 139% +/- 15%, 167% +/- 25%, and 183% +/- 35% at 1.7% enflurane, and from 43% +/- 8% to 78% +/- 7%, 137% +/- 20%, and 157% +/- 22% at 3.4% enflurane, respectively. The decreases in cardiac output by 1.7% and 3.4% enflurane were reversed by the intravenous administration of 3 micrograms.kg-1.min-1 of dobutamine. Cardiac output was significantly increased by administration of 10 mL/kg of autologous blood at 1.7% enflurane, but did not significantly increase at 3.4% enflurane. Increasing the heart rate did not significantly increase cardiac output at 1.7% and 3.4% enflurane. The results of this study suggest that increasing cardiac contractility is the most effective therapeutic means of reversing circulatory depression during enflurane anesthesia.

Anesthesia↗
PubMed1991

Exercise-induced phospholipid degradation in the equine skeletal muscle and erythrocytes.

To understand the pathogenesis of equine exercise-induced myopathies and hemolysis, changes of phospholipid peroxidation products in the equine middle gluteal muscle and erythrocytes following the high-speed treadmill exercise were studied. In the skeletal muscle, the peroxidized phosphatidylethanolamine (PE) were increased at 24 hours after the exercise. The malondialdehydes (MDAs) were also increased as the protein-bound MDAs following exercise. In the erythrocytes, the peroxidized PE were significantly decreased at 24 hours after the exercise. The protein-bound MDAs were significantly increased at 5 min after the exercise and returned to the base values at 24 hours after the exercise. These findings indicate that the PE is more susceptible to in vivo oxidative effects than the other phospholipid classes, and the accumulation of the protein-bound MDAs is considered to play some cytotoxic roles in the equine skeletal muscle and erythrocytes following exercise.

Animals↗
PubMed1991

In situ hybridization for the detection of feline interleukin 1 alpha mRNA on the paraffin-embedded section using biotin-labeled probes.

In situ hybridization (ISH) technique with a biotin-labeled probe was established for detecting feline interleukin 1 (IL-1) alpha mRNA in necropsied specimens. Homology between human IL-1 alpha cDNA used as a probe and feline IL-1 alpha mRNA was confirmed by means of dot blot hybridization using the biotin-labeled probe. Hence, we tried by this biotinylated probe to detect mRNA of IL-1 alpha in paraffin-embedded sections. The following results were obtained for the routine procedures: 1) coating slides with poly-L-lysine and/or heating at 60 degrees C at least for 6 hours gave an excellent result for the adhesion of the tissue sections, 2) 10 micrograms/ml solution of proteinase K treatment for 30 minutes or 50 to 100 micrograms/ml solution of proteinase K treatment for 10 to 30 minutes at 37 degrees C gave the good results in the detection of ISH signal, 3) suitable denaturation time of probes at 70 to 90 degrees C was 5 to 15 minutes, and 4) effective hybridization was obtained by incubation for 24 hours at 4 degrees C, for 18 to 24 hours at 25 degrees C or for 5 to 24 hours at 37 degrees C.

Animals↗