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Biomedical subjects

H Sekiguchi

Publications and source records attributed to H Sekiguchi.

At least 109 records · Page 6Linked to original sources
PubMed1991

In vitro effect of additives in benzodiazepine solutions on the superoxide anion-generating system in polymorphonuclear leucocytes.

Inhibitory effects of diazepam and flunitrazepam on the superoxide anion (O2-)-generating system in granulocytes were examined for their clinical relevance. When the effects of commercial solutions and pure preparations were compared using porcine and human polymorphonuclear leucocytes in vitro, the solutions were found to be more inhibitory than the pure drugs by 4-11 times, indicating that inhibition was caused mainly by the additives in the solutions. Concentrations of the additives required for 50% maximal inhibition of the system were 2.3, 7.5 and 0.9 microliters ml-1 for propylene glycol, ethanol and diazepam and flunitrazepam were 220 and 190 micrograms ml-1, respectively, under comparable conditions. However, plasma concentrations of the benzodiazepines and their additives during clinical use were far less than these inhibitory concentrations, indicating that they had no appreciable effect on the O2(-)-generating system in polymorphonuclear leucocytes of patients.

Animals↗
PubMed1991

[Healing promoting effect of azuletil sodium (KT1-32) on experimental chronic gastric ulcers and acceleration of healing in SPF environment].

We examined the healing promoting effects of azuletil sodium on acetic acid and clamping cortisone-induced gastric ulcer in rats. For the experiments on clamping-cortisone gastric ulcer, we used not only conventional rats in conventional conditions but also specific pathogen free (SPF) rats on SPF environment in order to prevent infection. The following results were obtained. 1) In acetic acid ulcer, azuletil sodium (AZE) (greater than or equal to 90 mg/kg/day, p.o.) significantly decreased ulcer index. As estimated on the basis of stage analysis (Ulcer, Healing, Scar), AZE (greater than or equal to 30 mg/kg/day, p.o.) significantly promoted the healing of ulcers. 2) In clamping cortisone ulcer (conventional), AZE (100 mg/kg/day, p.o.) significantly promoted the regeneration of blood vessels. 3) In clamping cortisone ulcer (SPF), AZE at greater than or equal to 30 mg/kg/day and 100 mg/kg/day significantly increased the healing index and mucosal regeneration index, respectively. 4) In clamping cortisone ulcer (SPF), the infection that was observed in the conventional test was not seen at all and the acceleration of healing was observed. Furthermore, the extent of adhesion was also reduced, and the standard errors of various healing indices were smaller. From these results, it is concluded that AZE accelerated the healing of experimentally-induced gastric ulcers in rats.

Animals↗
PubMed1991

[Does pulmonary air embolism affect the pulsatility of pulmonary capillary blood flow in dogs?].

The difference in the uptake rate through the lungs between nitrous oxide and oxygen has been shown to represent the pulmonary capillary blood flow (Qc). The pulsatility of Qc, defined as the ratio of maximum Qc and mean Qc (Qc max/Qc), the ratio of Qc max and stroke volume (Qc max/SV), and the ratio of systolic Qc and SV (Vsyst/SV), has been also shown to indicate the pulmonary vasodilation as well as vasoconstriction. We measured Qc by means of body plethysmography in dogs with pulmonary air embolism, in order to evaluate its effect on the pulmonary vasculature. Ten adult dogs were anesthetized with pentobarbital and pancuronium, and were mechanically ventilated. A volume of air (0.5 ml/kg) was injected into the central vein. Although there was no significant change in systemic blood pressure, cardiac output, heart rate, and airway pressure after the injection of air, pulmonary arterial pressure and pulmonary vascular resistance increased significantly. Qc, Qc max, Qc max/Qc, and Qc max/SV decreased significantly after the air injection. Since these findings suggest that the pulmonary air embolism provoked pulmonary vasoconstriction, and attenuated the pulsatility of Qc, optimal pulmonary vasodilation therapy would be recommended to improve the pulmonary hypertension secondary to pulmonary air embolism.

Animals↗
PubMed1990

[General pharmacological properties of an anti-ulcer drug, azuletil sodium (KT1-32)].

Azuletil sodium (AZE, 100 mg/kg, p.o.) did not affect the general behaviors, spontaneous motor activity, pentobarbital-induced hypnosis and body temperature. Furthermore, it did not elicit anticonvulsant and muscle relaxant actions. However, AZE (300 mg/kg, p.o.) elicited a stiff gate and slightly inhibited the spontaneous motor activity and electroshock-induced convulsions. It had no influence on spontaneous EEG activities, even at 30 mg/kg, i.v. AZE inhibited acetic acid-induced writhing moderately at doses above 100 mg/kg. AZE at concentrations up to 10(-5) g/ml did not affect agonist-induced contractions of the isolated ileum, trachea, vas deference and uterus, but inhibited serotonin and oxytocin-induced contraction at concentrations above 3 x 10(-4) and 10(-5) g/ml, respectively; and it also depressed spontaneous movements of the ileum and uterus at concentrations above 3 x 10(-4) g/ml. AZE caused no changes in blood pressure (BP), heart rate (HR), left ventricular pressure, ECG, tracheal pressure (TP), femoral blood flow (FBF) and coronary blood flow (CBF) at doses up to 10 mg/kg, i.v. in anesthetized dogs, but it caused an increase or a decrease in BP, an increase in TP and an increase in CBF at 30 mg/kg, i.v. However, even at 300 mg/kg, p.o., it caused no changes in BP and HR in conscious rats. AZE moderately promoted the charcoal transport. AZE at doses up to 300 mg/kg, p.o. did not affect urine volume, urinary electrolyte excretion, blood glucose and prothrombin time. These results suggest that AZE at anti-ulcer doses of 10-100 mg/kg, p.o. does not have noticeable effects on general pharmacological properties, and there is no marked differences as compared with those of GAS.

Animals↗
PubMed1990

[Acoustic evaluation of postoperative hoarseness in adult patients].

The present study was performed to evaluate postoperative hoarseness quantitatively by means of acoustic wave form analysis. Pitch and amplitude perturbation (PPQ, and APQ), and normalized noise energy (NNE) were measured along with the frequency characteristics in 51 adult patients undergoing elective surgery. The normal values for these acoustic parameters were less than 0.5%, less than 2.0%, and less than -10 dB, respectively. Vowel sound "E" was recorded and evaluated before the induction of anesthesia and on the morning of the day after the surgery. PPQ increased from 0.39% to 1.00% (P less than 0.05), APQ increased from 3.34% to 6.62% (P less than 0.05), and NNE increased from -9.19 dB to -4.74 dB (P less than 0.05). Eighteen percent of the patients showed abnormal values in all parameters preoperatively, but 45% of the patients postoperatively (P less than 0.05). These findings suggest that even the short term intubation resulted in the postoperative hoarseness, and this method is a useful and non-invasive bed-side test to evaluate postoperative hoarseness quantitatively.

Acoustics↗
PubMed1990

[Induction of differentiation of myelomonocytic leukemia cells by mitoxantrone].

We studied the effect of mitoxantrone (MIT) on the proliferation and differentiation of murine myelomonocytic leukemia cell line WEHI-3B (D+), human myelocytic leukemia cell line HL-60 and cells from patients with newly diagnosed acute nonlymphocytic leukemia (ANLL). In a liquid culture, growth inhibition and differentiation of WEHI-3B (D+) cells to mature myeloid cells and a reinforcement tendency of the induction of nitroblue tetrazolium reducing capacity as well as of ASD chroloacetate esterase staining was observed by the treatment with MIT. Fresh ANLL cells classified as M4 were induced by MIT to undergo terminal differentiation to macrophage-like cells. Since at concentrations of WEHI-3B (D+) cells of less than 1 x 10(5)/ml induction of differentiation was observed due to MIT, it is suggested that its mechanism of action differs from that of the induction of differentiation by granulocyte colony-stimulating factor and is due to the direct action of MIT.

Adolescent↗
PubMed1989

Fundamental study on latex reagents for agglutination tests.

Competitive adsorption of Fab and Fc fragments on to particles revealed that the main driving forces for the adsorption of Fab and Fc fragments are ionic and hydrophobic forces, respectively. Latex particles were sensitized with antihuman C-reactive protein-antibody under a condition where ionic binding force was suppressed, and hence antibody was supposed to attach to the particles predominantly at the Fc site. The resulting latex indicated a high efficiency for the determination of C-reactive protein. Among the latexes used, a partially hydrolysed styrene-acrylamide copolymer latex was the best with respect to test efficiency and storage stability.

Adsorption↗
PubMed1989

Mechanical adaptation of heart rate change for coronary circulation in patients with and without ventricular hypertrophy.

To clarify the mechanical adaptation and interference of coronary vessels, we studied hemodynamics of coronary circulation in control and 4 different pacing rates (80, 100, 120, 150/min) in 5 patients with angina pectoris (AP) and in 5 patients with hypertrophic cardiomyopathy (HCM). Coronary sinus flow (CSF) was measured by a Webster's thermodilution catheter, and we applied ascorbic acid-platinum reaction for the mean transit time measurement in left coronary flow (t0-t2). Coronary vascular bed (CVB) was obtained by multiplying CSF and t0-t2. CSF in AP gradually increased from 104 +/- 21 ml/min at 72/min to 148 +/- 42 ml/min at 120/min, while CSF in HCM changed slightly from 91 +/- 25 ml/min at 64/min to 94 ml/min at 120/min. Average t0-t2 in HCM was 6.0 +/- 1.6 sec in control which was significantly lower than that in AP (7.8 +/- 0.7 sec). Calculated CVB in AP increased at any given heart rate up to 120/min (13.5 +/- 2.4, 15.8 +/- 1.7, 15.0 +/- 4.7, 15.1 +/- 4.3 ml), but CVB in HCM decreased from 9.1 +/- 2.3 ml at 64/min to 8.1 +/- 1.7 ml at 120/min. These data suggest that myocardial compression and suction at different heart rates and with different cardiac muscle structures play an important role for beat to beat adjustment of coronary circulation in cardiac cycle.

Adaptation, Physiological↗
PubMed1989

[Interference in double-determinant monoclonal antibody-based assay for carcinoembryonic antigen (CEA)].

We investigated the false positive phenomena in immunoassays of carcinoembryonic antigen (CEA) using mouse monoclonal antibodies, and studied the properties of interfering substances and the method to eliminate non-specific interference. Serum samples from 2,250 patients, which indicated more than 10 ng/ml of CEA with EIA test kit (Boehringer Mannheim Yamanouchi; BMY) in about 25,000 samples of CEA tests, were subjected to extraction by heating at 70 degrees C followed by CEA measurement of the supernatant. The overall correlation was good between CEA values of the original and extraction methods, but CEA values in 55 cases were found to be remarkably higher in the non-extracted method than the extraction method. CEA titers of 20 samples of the discrepant cases were measured by various commercial kits, and the result indicated that non-specific interference was unavoidable in any kit using a monoclonal antibody-based double-determinant immunoassay, in spite of difference in degree and frequency of interference. The interfering activity of two patients serum with remarkably discrepant values eluted at the void volume of a large molecular size of more than 1,000 kDa in gel chromatography of Sephacryl S-300. The non-specific interference was reduced by addition of mouse gamma-globulin to the buffer of BMY kit and abolished by pretreatment of the serum with heat-killed cells of Staphylococcus aureus, suggesting that interference might be caused by some species of immunoglobulin being able to bind mouse gamma-globulin.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1989

[Effect of sevoflurane on respiratory impedance measured by the forced oscillation method with random noise input].

This study was performed to investigate the effect of sevoflurane, a new inhalation anesthetic, on the respiratory impedance measured by forced oscillation method with random noise input. Random noise (1 to approximately 25Hz) oscillated by a loudspeaker was imposed on the respiratory system of dogs through a tracheostomy and the oscillatory pressure wave and flow wave were monitored at the same point with a pressure transducer and a pneumotachograph. This procedure was repeated during inhalation of 100%-oxygen, 2.0%-then 4.0%-sevoflurane-oxygen mixture, respectively. Impedance was calculated with fast Fourier transform by spectrum analyzer and a personal computer. During inhalation of 4.0%-sevoflurane-oxygen mixture, respiratory impedance especially respiratory resistance decreased at the high frequency area (6to approximately 20Hz), but 2.0%-sevoflurane-oxygen mixture did not cause a significant change of respiratory impedance. This study suggests that inhalation of an anesthetic concentration of sevoflurane produces weak bronchodilation compared with halothane or enflurane.

Anesthetics↗
PubMed1989

[Partitioning and measurement of respiratory impedance into central and peripheral airways with catheter tip type transducer].

In this study, we have examined the availability of catheter tip type transducer for the partitioning of respiratory impedance. Total respiratory resistance and reactance from 1 to 20 Hz determined by forced oscillation method with random noise input in anesthetized dogs were partitioned by catheter tip type transducer into central airway resistance (Rc) and reactance (Xc) as well as peripheral resistance (Rp) and reactance (Xp). Intratracheal acetylcholine (0.1g) increased Rp at the wide frequency range (from about 1 to 20 Hz), although Rc did not change with it. The decreases of Rc at higher frequencies (over 12Hz) were produced by intratracheal salbutamol (10mg), whereas Rp did not change significantly. These results suggest that the predominant site of action of intratracheal acetylcholine and salbutamol is peripheral airway and central airway respectively. We have concluded that the respiratory impedance can be partitioned noninvasively with catheter tip type transducer without pneumothorax and hemorrhage caused with the retrograde catheter. This method can be applied clinically during general anesthesia or in intensive care.

Acetylcholine↗
PubMed1987

[Effects of troxipide on acute gastric lesions in rats].

Effects of troxipide on several acute gastric lesions in rats were investigated in comparison with those of cetraxate. Troxipide (100, 200, 300 mg/kg) and cetraxate (100, 300, 1,000 mg/kg), given orally, dose-dependently protected the gastric mucosa from damage due to ethanol. Aspirin- and 0.6 N HCl-induced gastric lesions were dose-dependently inhibited by troxipide (200, 300 mg/kg), but only significantly inhibited by cetraxate at high dose (1,000 mg/kg). Troxipide (100, 200, 300 mg/kg) dose-dependently prevented the formation of gastric lesions induced by water-immersion stress, whereas cetraxate (600, 1,000 mg/kg) also significantly prevented gastric lesions. That is, protective effects of troxipide were much more potent than those of cetraxate against aspirin-, 0.6 N HCl- and water-immersion stress-induced gastric lesions, whereas both were almost equal against ethanol-induced gastric lesions. In addition, cytoprotective effects of troxipide against ethanol-induced lesions were most remarkable at 10, 30, 60 min after administration (100, 300 mg/kg) and lasted for up to 240 min. These results suggested that troxipide might be useful for the treatment of acute gastric lesions in humans.

Acute Disease↗