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Biomedical subjects

K Ogino

Publications and source records attributed to K Ogino.

At least 127 records · Page 7Linked to original sources
PubMed1993

[Damage to cultured corneal endothelium caused by ultrasound during phacoemulsification].

An experimental study was performed to estimate the degree of corneal endothelial damage caused by ultrasound during phacoemulsification. Cultured corneal endothelium prepared from bovine eyes was exposed to ultrasound. Dead cell rates were determined by counting the number of cells positively stained by trypan blue under various conditions of ultrasonic radiation. Dead cell rate increased from 13 +/- 2% to 39 +/- 4% (n = 5, Mean +/- S.D.) as ultrasonic duration was prolonged from 15 seconds to 45 seconds. Dead cell rate increased from 6 +/- 1% to 39 +/- 4% as ultrasonic power increased from 60% to 100%. Dead cell rate increased from 8 +/- 1% to 44 +/- 11% as the distance of the phaco tip decreased from 7 mm to 4 mm. Dead cell rate increased from 4 +/- 2% to 35 +/- 7% as the angle of the phaco tip increased from 30 degrees to 90 degrees. We confirmed that endothelial damage depended on ultrasonic duration, ultrasonic power, the distance of the phaco tip, and the angle of the phaco tip. We suggest that the endothelium is damaged mainly by shock waves emanating from the phaco tip.

Animals↗
PubMed1993

[Effects of typhoon-caused power failure on medical care facilities].

In the evening of September 27, Typhoon 19 passed Yamaguchi prefecture. The wind velocity exceeded anything that the local meteorological observatory has ever recorded so far in this area. When the typhoon was off shore near Yamaguchi prefecture, the gale brought down many electric-light poles around Hofu city with power failure in Hofu city continuing for more than a week. At the same time the total number of emergency patients in Hofu area was the most in the prefecture. Because the power failure continued for many days, there was more indirect damage attributable to this power failure than the damage related directly to the typhoon. The capacity of the emergency electric power generator equipment installed in the Central prefectural hospital in Hofu city is the largest in Yamaguchi prefecture. Even while electric power failed completely in the Hofu city area, treatment of most of the emergency patients at this hospital was possible. There is no hospital that has as large an electric generator as the Central hospital has. Had this typhoon hit in another area, the ensuring confusion which might have occurred at hospitals in that area would have put many patients in danger with the power failure in many hospitals. Power consumption needs in hospitals have increased over that expected on the time the hospital was built. Therefore, the electric power generators installed in hospitals are of the times very small and unable to cope with massive electrical outage.

Disasters↗
PubMed1992

Zinc hydroxide stimulates superoxide production by rat alveolar macrophages.

The effect of zinc hydroxide on superoxide (O2-) production by rat alveolar macrophages was determined by chemiluminescence and by cytochrome c reduction. Zinc ions had no effect on the chemiluminescence of unstimulated alveolar macrophages. By contrast, zinc hydroxide (ZnOH2), a neutralized form of zinc ions, increased the chemiluminescence level and O2- release. Increased O2- release was inhibited by pertussis toxin, isoquinoline sulfonamide and pretreatment with EGTA. These findings indicate that zinc hydroxide formation from zinc compounds can stimulate the O2- production by alveolar macrophages by receptor-mediated and Ca(2+)-dependent process.

Animals↗
PubMed1992

Antiulcer mechanism of action of rebamipide, a novel antiulcer compound, on diethyldithiocarbamate-induced antral gastric ulcers in rats.

The mechanism of the inhibitory action of rebamipide, a new mucosal protective drug, was studied using rats with diethyldithiocarbamate-induced gastric antral ulcers. Rebamipide reduced ulcer formation and inhibited the elevation in lipid peroxide concentration in the gastric mucosa. Rebamipide inhibited both luminol- and lucigenin-dependent chemiluminescence of neutrophils activated by formyl-methionyl-leucyl-phenylalanine. Rebamipide did not alter the reduction of cytochrome c induced by the xanthine-xanthine oxidase system or the NADPH-dependent microsomal lipid peroxidation in the liver. These findings suggest that rebamipide prevents diethyldithiocarbamate-induced gastric ulcer formation by inhibiting neutrophil activation.

Alanine↗
PubMed1992

Suppression of sympathetic nervous system activity by nicorandil during exercise.

1. Treadmill testing was done and plasma epinephrine and norepinephrine were measured during exercise and recovery in 21 patients with coronary artery disease given nicorandil. 2. Epinephrine levels during exercise did not change significantly with nicorandil, but the percent change in epinephrine with nicorandil tended to be lower during exercise. 3. Norepinephrine levels after exercise were suppressed with nicorandil (with, 424 +/- 15 pg/ml; without, 760 +/- 16, P less than 0.05). 4. Also, the percent change in norepinephrine with nicorandil was significantly decreased during exercise and recovery (with, 259 +/- 11%; without, 555 +/- 19, P less than 0.01). 5. Therefore, nicorandil suppressed the sympathetic nervous system hyper-response to exercise.

Adult↗
PubMed1992

Effect of alacepril on blood pressure and neurohumoral factors at rest and during dynamic exercise in patients with essential hypertension.

We assessed blood pressure and neurohumoral factors at rest and during exercise in 10 patients with essential hypertension before and after treatment with the new angiotensin converting enzyme inhibitor, alacepril (25-50 mg day-1). Alacepril significantly lowered mean blood pressure at rest and at the same exercise load as before treatment without affecting heart rate response. The response of plasma renin activity, plasma aldosterone, and plasma adrenaline were not changed by alacepril, but increase of plasma angiotensin II and plasma noradrenaline during exercise were significantly attenuated after alacepril treatment (ANOVA, P = 0.04, both). The change in mean blood pressure during exercise was positively correlated with the decrease in plasma angiotensin II (r = 0.65, P < 0.05). These results demonstrated that alacepril was effective in essential hypertension both at rest and during exercise, suggesting that the antihypertensive effect during exercise might be related to the decrease in pressor hormones, especially in plasma angiotensin II.

Adult↗
PubMed1992

Plasma catecholamine responses to dynamic exercise in patients with coronary artery disease--the relationship between sympathetic activity and systolic blood pressure and exercise-induced ventricular arrhythmias.

In order to investigate the relationship between sympathetic activity and postexercise systolic blood pressure (SBP) and exercise-induced ventricular arrhythmias in patients with coronary artery disease (CAD), we studied 38 patients and 9 normal subjects who underwent treadmill testing. Peak pressure-rate product was similar in the 2 groups. The plasma concentrations of norepinephrine and epinephrine at rest and immediately after exercise were significantly higher in patients with CAD compared with normal subjects (norepinephrine at rest, p < 0.01; norepinephrine immediately after exercise, p < 0.05; epinephrine at rest, p < 0.05; epinephrine immediately after exercise, p < 0.05). The level of norepinephrine immediately after exercise was significantly higher in 15 patients with a postexercise SBP increase than in 23 patients without that SBP change (p < 0.05), whereas the level of epinephrine was similar in the 2 groups. The level of epinephrine immediately after exercise was significantly higher in 10 patients with exercise-induced premature ventricular contractions than in 28 patients without those arrhythmias (p < 0.05), whereas the level of norepinephrine was similar in the 2 groups. We conclude that a postexercise SBP increase is related to the augmentation of sympathoneural activity and that exercise-induced ventricular arrhythmias are related to the augmentation of sympathoadrenal activity.

Arrhythmias, Cardiac↗
PubMed1992

Serum levels of lipids and apolipoproteins in angiographically assessed coronary artery disease in Japanese patients.

Serum total cholesterol (T-CHO), triglyceride (TG), high density lipoprotein cholesterol (HDL-C) and apolipoproteins (apo A-I, A-II, B, C-II, C-III and E) values were determined in 143 Japanese subjects undergoing coronary angiography. Among the factors measured, T-CHO, TG, apo B and C-III levels were significantly higher in patients with coronary artery disease (CAD) than in those without CAD. The HDL-C/T-CHO ratio was also significantly lower in patients with CAD. Although no parameters show differences between the group without CAD and the group of single vessel disease, T-CHO and apo B were significantly higher in the groups with double and triple vessel disease, and TG and apo C-III were also higher in the group with triple vessel disease compared with the normal group. Furthermore, the HDL-C/T-CHO ratio was significantly lower in the double and triple vessel groups, and HDL-C was lower only in the triple vessel group. The results indicate that changes in these parameters suggest a high likelihood of multiple vessel disease, and that an increase in TG and apo C-III levels is also one of the important indicators for CAD even in Japanese patients.

Aged↗
PubMed1992

[Cardiac and plasma catecholamine response to dynamic exercise in hyperthyroidism].

To investigate cardiac and sympathoadrenal responses to dynamic exercise, heart rate, systolic blood pressure, serial plasma norepinephrine (NE) and epinephrine (E) concentrations during multistage treadmill exercise were measured in 24 hyperthyroid patients (mean age; 42 +/- 16) and 24 age-sex matched control subjects. Eleven patients were re-examined in the euthyroid state after antithyroid therapy. Exercise duration was shorter in patient with hyperthyroidism. Also, the heart rates and systolic blood pressures at rest and in the early stage of exercise were significantly higher in hyperthyroidism. NE at rest (normal vs hyperthyroid: 124 +/- 10 vs 80 +/- 7 pg/ml, p < 0.01) and NE at peak exercise (475 +/- 38 vs 310 +/- 38 pg/ml, p < 0.01) were lower in hyperthyroidism. E at rest (22 +/- 2 vs 29 +/- 4 pg/ml, n.s.) did not differ, however, E during the first stage of exercise (30 +/- 3 vs 69 +/- 12 pg/ml, p < 0.01) was higher in hyperthyroidism. Re-examination for the euthyroid state revealed the decreases in the heart rates and systolic blood pressures at rest and in the early stage of exercise, and the normalization of the NE and E response. Thus, patients with hyperthyroidism was in the hyperdynamic cardiac state at rest and during dynamic exercise, which was accounted for by decreased sympathetic nervous activity and increased adrenomedullary responses. These modifications of sympathoadrenal response seemed reversible when patients were controlled by antithyroid therapy.

Adolescent↗
PubMed1991

The longest 18S ribosomal RNA ever known. Nucleotide sequence and presumed secondary structure of the 18S rRNA of the pea aphid, Acyrthosiphon pisum.

An EMBL4 recombinant phage which encodes one of the full length of the aphid ribosomal DNA has been isolated from the aphid genomic library. Determination of the complete nucleotide sequence of the aphid 18S rRNA gene revealed that it is 2469 bp with a G + C content of 59%. The aphid 18S rRNA gene studied here is the longest and has the highest G + C content among the 18S rRNA genes examined so far. Evidence provided by the S1 nuclease assay suggests that the aphid 18S rRNA gene examined in this study is not a pseudogene containing an insertion sequence. Based on the nucleotide sequence of the 18S rRNA gene, we constructed a presumed secondary-structure model of the aphid 18S rRNA. In the aphid 18S rRNA, the eucaryote-specific E21 and 41 region are supposed to be longer and more complex than the counterparts of other 18S rRNA.

Animals↗
PubMed1991

Effects of various mucosal protective drugs on diethyldithiocarbamate-induced antral ulcer in rats.

This study was designed to determine the effects of exogenous Cu,Zn-superoxide dismutase (SOD) and various mucosal protective agents against antral ulcer induced by diethyldithiocarbamate (DDC), inhibitor of Cu,Zn-SOD. Exogenous Cu,Zn-SOD reduced ulcer formation and prevented a decrease in SOD activity in gastric mucosa. This result indicates that maintenance of mucosal SOD activity is essential to prevent the ulcerogenicity of DDC. Many mucosal protective drugs that increase blood flow, mucus secretion, and endogenous prostaglandin failed to prevent ulcer formation and decrease of mucosal SOD activity. Rebamipide, however, significantly reduced ulcerogenesis and maintained mucosal SOD activity. This suggests that rebamipide has new protective effects on gastric mucosa.

Alanine↗
PubMed1991

Slow recovery of conduction velocity from use dependent inhibition induced by quinidine in guinea pig ventricular myocardium.

STUDY OBJECTIVE: The aim was to investigate whether the use dependent effects of antiarrhythmic drugs on the Na+ current could be applied to explain their effects on impulse conduction. DESIGN: Trains of rapid stimuli were applied to guinea pig papillary muscles via an electrode in the presence of quinidine (20 and 60 mumol.litre-1), and the conduction velocity was determined from the time difference between two signals of the maximal rate of rise (dV/dtmax) of the action potentials at two separate sites. The relationship of the time constants of the onset and recovery from the use dependent inhibition induced by quinidine was determined for the dV/dtmax and the conduction velocity. EXPERIMENTAL MATERIAL: Six male Hartley guinea pigs weighing 200 to 300 g were killed by a blow to the head and the papillary muscles were rapidly excised from the right ventricles. The preparations were superfused with Tyrode solution. MEASUREMENTS AND MAIN RESULTS: The rate of onset of the use dependent inhibition of conduction velocity and that of the square of conduction velocity were both faster than the simultaneously measured rate of onset of dV/dtmax inhibition induced by 20 mumol.litre-1 quinidine at high frequency stimulation. The relation between the rates of onset of the use dependent inhibition of conduction velocity (and the square of conduction velocity) and dV/dtmax became weak with low frequency stimulation and in the presence of 60 mumol.litre-1 quinidine. However, the recovery of conduction velocity (and the square of conduction velocity) from quinidine induced use dependent blockade, as measured by the extrastimulation method, appeared to be slower than the recovery of dV/dtmax. These results may be explained by a transient change in intracellular and intercellular conditions, such as an increase in internal resistance. CONCLUSIONS: The onset and recovery of the use dependent inhibition of conduction by antiarrhythmic drug may not always parallel the changes of the dV/dtmax of action potential in multicellular muscle preparations.

Action Potentials↗