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Biomedical subjects

S Onodera

Publications and source records attributed to S Onodera.

At least 181 records · Page 10Linked to original sources
PubMed1990

Glycosaminoglycans in neurofibromas.

Glycosaminoglycan (GAG) contents in neurofibromas (NFs) were examined to clarify how well they corresponded to their histological features. Eight cutaneous NFs and three plexiform NFs from five patients with Recklinghausen's (R) disease, two senile NFs and control dermis were subjected to the isolation of GAGs. The GAGs were then fractionated and quantitated with two-dimensional electrophoresis on cellulose acetate membranes. Dry weight/wet weight ratios of the NFs were lower than those of the controls; the plexiform NFs were the lowest. In these plexiform NFs, hyaluronic acid (HA) content was most increased and dermatan sulfate (DS) content most decreased, resulting in a marked decrease in the DS/HA ratio. Both cutaneous and senile NFs showed moderate decreases in DS content, increases in chondroitin sulfate and heparan sulfate contents, and slight increases in HA content, resulting in moderate decreases in the DS/HA ratio. Considering that cutaneous or senile NFs are relatively more fibrotic tumors than plexiform NFs, these differences in the GAGs between plexiform NFs and cutaneous or senile NFs appear to be consistent with the changes in GAGs previously described in physiological and pathological conditions such as fibrotic diseases. Thus these results suggest that studies of hereditary disorders like R disease might be useful for understanding the pathogenesis of so-called acquired diseases with unknown etiology.

Adult↗
PubMed1990

[Detection of African type penicillinase-producing Neisseria gonorrhoeae in Japan].

The Plasmid DNA patterns of 22 penicillinase-producing Neisseria gonorrhoeae (PPNG) strains isolated from male patients with gonococcal urethritis in 1988 at Tokyo Metropolitan Taito Hospital were determined. The 3.3 megadalton plasmid, the so called the African type plasmid, was present in 3 isolates out of 22 PPNGs, all of which occurred with a conjugative 24.5 megadalton plasmid. 4.4 megadalton plasmid was present in 19 isolates out of 22 PPNGs, 5 of which occurred with a conjugative 24.5 megadalton plasmid. The infective sources of the 3 cases of the African type PPNGs were found as 1 from philippines and 2 from prostitutes, so called Soap Land Girl in Japan. And they suggests that the African type PPNGs are already common in Japan.

Adult↗
PubMed1990

Treatment of canine acute pulmonary embolic shock--effects of isoproterenol and norepinephrine on hemodynamics and ventricular wall motion.

To determine indications for isoproterenol and norepinephrine, the effects of each drug on acute pulmonary embolic shock were compared with those of mechanical occlusion of the descending aorta (AO). In 18 dogs, we measured the changes in the hemodynamics and the ventricular wall motion in experimental pulmonary embolic shock. When the left ventricular systolic pressure decreased to 70 mmHg (shock), dogs were treated with isoproterenol, norepinephrine or AO. At the shock, the difference between the left and right ventricular pressures became negative. The changes in the left and right ventricular septum-free wall diameter (LVD, RVD) resulted in a significant leftward shift of the interventricular septum (IVS), and systolic shortening in LVD was extremely diminished. Isoproterenol administration decreased left and right ventricular end-diastolic pressure (LVEDP, RVEDP), but did not improve the reversion in RVEDP and LVEDP. The leftward shift of the IVS was not restored to normal. Following either norepinephrine administration or AO, the difference between the left and right ventricular pressures was restored to normal. Improvements in left ward shift of the IVS and systolic shortening of each diameter were observed. The similarity of norepinephrine administration to AO suggests that in the treatment of acute pulmonary embolic shock, restoration of systemic pressure for the maintenance of coronary perfusion, may be of primary importance. We concluded that norepinephrine is superior to isoproterenol for improvement of hemodynamics and ventricular wall motion in severe pulmonary embolic shock.

Acute Disease↗
PubMed1990

Changes in the pulmonary vascular input impedance in patients with atrial septal defect after surgical correction.

In order to evaluate whether there is pulmonary vascular disease in patients with atrial septal defect (ASD), we used the pulmonary vascular input impedance to estimate the stiffness of the pulmonary vessels with before and after surgical intervention. Ten control subjects and 11 patients with ASD (9 operable and 2 inoperable) were examined. In preoperative patients the decreased total pulmonary resistance (Rin) and pulmonary vascular resistance appeared to open new parallel vascular channels with increased blood flow. Further, there were no significant differences in the pulmonary vascular input impedance spectrum and phase, and characteristic impedance among control subjects, preoperative and postoperative patients. Although distensibility of the pulmonary vascular wall in operable patients was similar to that in control subjects, an excessive elevation in Rin and input impedance modulus was observed in inoperable patients. The results demonstrate that the normal input impedance spectrum and phase in patients with ASD is predictive of a good prognosis after successful surgical correction.

Adolescent↗
PubMed1990

[Effects of aging and the autonomic nervous system-related agents on the intravesical pressure of the bladder in situ in female rats].

We investigated the effects of several autonomic nervous system-related agents on the intravesical pressure (IVP) in adult (11-23 weeks old, 200-350 g) and aged (2 years old, 350-770 g) female rats. Acetylcholine induced a dose-dependent and transient increase of IVP, which was competitively antagonized by pirenzepine weakly and by atropine strongly. These results suggest the predominance of M-2 receptors. Adrenaline induced dual actions of decrease and increase of IVP at low and high doses, respectively. Adrenaline (at only high doses), noradrenaline and phenylephrine increased IVP but not clonidine, suggesting the predominance of alpha-1 receptors. Isoproterenol, salbutamol and clenbuterol decreased IVP to same extent and the effect of isoproterenol was markedly antagonized by propranolol and slightly by atenolol, suggesting the predominance of beta-2 receptors. ATP increased IVP dose-dependently but not adenosine, suggesting the predominance of P-2 receptors. Serotonin and prostaglandin F2 alpha also increased IVP. In aged rats, the maximal response to acetylcholine was lower than in adult rats and the decrease in IVP by low doses of adrenaline was not observed. These results suggest that the increase of IVP involves the participation of cholinergic M-2 receptors to a large extent and also serotonergic, adrenergic alpha-1 and purinergic P-2 receptors to some extent and that the responsiveness to acetylcholine is reduced by ageing.

Acetylcholine↗
PubMed1990

[Effects of beta-antagonists and beta 1-partial agonists on the pulmonary pressor response to 5-HT].

The effects of beta-antagonists (propranolol, pindolol, atenolol) and beta 1-partial agonists (xamoterol, denopamine) on the pulmonary circulation, and on the pressor response to 5-HT were investigated and compared with those of a beta-agonist, isoproterenol. These agents (at doses of 0.002-20 mg) were administrated into the isolated lung lobe perfusion system excised from mongrel dogs (7-12 kg in weight). Under standard conditions (mean pulmonary inflow pressure, 15 mmHg; mean outflow pressure, 5 mmHg), propranolol and atenolol had no effect on pulmonary vascular resistance (PVR) at the tested doses, but pindolol which has intrinsic sympathomimetic activity (ISA) and two beta 1-partial agonists significantly decreased PVR in a dose-dependent manner (each n = 7). Isoproterenol, up to a dose of 0.2 mg, markedly decreased PVR, but induced vasoconstriction in larger doses (n = 7). Propranolol and xamoterol similarly reduced the pressor response to 30 micrograms of 5-HT from a dose of 2 mg, and these inhibitory actions were greater than those of the other drugs. Pindolol and denopamine inhibited the 5-HT response in a dose of 20 mg, whereas atenolol only augmented the response in a dose-dependent manner. In conclusion, beta-antagonists with ISA (including beta 1-partial agonist activity) can dilate the pulmonary vessels in a dose-dependent manner, but not beta-antagonists without ISA. Furthermore, the 5-HT inhibitory effects caused by relatively large doses of beta-antagonists, except for atenolol, may be related to the 5-HT receptor blockade or other unknown mechanisms, including calcium influx or prostaglandin synthesis, but not to the beta-receptor blockade.

Adrenergic beta-Agonists↗
PubMed1990

[Effects of chronic volume loading on atrial natriuretic peptide release in human].

In the present study, we investigated whether release of hANP increases during mild and long-term volume loading. Eight lung cancer patients in good performance state (five men and three women, 35 to 68 years), who needed to have pre-hydration for cancer chemotherapy with cisplatin, were infused with about seven liters of isotonic saline over 48 hours through Swan-Ganz catheter placed in the pulmonary artery. The mean infusion rate was 0.042 ml/min.kg body weight. During the infusion, change in plasma volume (delta PV) increased by 5.8 + 3.3 (mean +/- SE) %. Right atrial pressure (RAP) did not change significantly, and pulmonary artery wedge pressure (PAWP) increased from 4.3 +/- 1.0 to 5.8 +/- 0.7 mmHg. Plasma hANP was significantly elevated from 50.6 +/- 0.7 to 105.1 +/- 19.3 pg/ml by the second day of the infusion with a suppression of plasma renin activity (PRA) and aldosterone, though plasma ADH did not change. The infusion rate at 20:00 on the first day was the same as that on the second day. Further increase in plasma hANP was shown at 20:00 on the second day compared with the level at the same time on the first day, though RAP, PAWP and delta PV did not change. These results indicate that mild and chronic volume loading increases plasma hANP, and suggest that the prolongation of volume expansion plays an important role in the releasing of hANP in humans.

Adult↗
PubMed1990

[Respiratory pathophysiology during sleep in patients with myotonic dystrophy].

Myotonic dystrophy is a genetic disorder inherited as an autosomal dominant trait. It is known to be associated with endocrine dysfunction, polar cataracts, cardiac abnormalities and other conditions. Respiratory distress constituents the principal problem in myotonic dystrophy. The author investigated postural change of respiratory function in 12 patients with myotonic dystrophy (MYD), and 7 patients with limb-girdle dystrophy (LG) and overnight polysomnography was performed on 10 patients with MYD and 5 patients with LG. The respiratory function in seated posture showed no significant difference between LG and MYD, but in patients with MYD, the vital capacity and the expiratory reserve volume in a supine posture was reduced in comparison to that during seated posture. However, the respiratory function in patients with LG was not significantly different in seated and supine postures. Also, in patients with MYD, there was a significant decrease in arterial PO2 from the seated posture to the supine posture, without a significant change in the arterial PCO2. However, in patients with LG, there was no significant change in arterial blood gas analysis parameters. It was speculated that these findings concerning respiratory function and blood gas analysis in patients with MYD were caused by the involvement of the diaphragm. In the supine posture, the diaphragm shifted to the cranial position because of the abdominal contents rising into thorax, therefore the lung volume was reduced and the ventilation-perfusion ratio deteriorated. The changes of respiratory function parameters and PaO2 were partly responsible for the hypoxemia observed during sleep in patients with MYD. Overnight polysomnography showed that 9 of the 10 patients with MYD and 1 of the 5 patients with LG presented apneas during sleep, particularly during REM, stage 1 and stage 2. Almost all apneas were central type, with a low percentage of obstructive apneas and the apnea index was 19.0/h (mean) in MYD, 6.5/h in one case of LG. These result strongly suggest that sleep apnea is of central origin, but the distinction between a central and an obstructive etiology is difficult in neuromuscular disease and particularly when a disorder of central ventilatory responsiveness is suspected. The respiratory function of MYD and LG in seated and supine postures was studied and overnight polysomnography performed. It was emphasized that it was important for the respiratory care of neuromuscular disease to consider the influence of postural changes in the respiratory function. The present series of studies revealed central sleep apnea in the patients with myotonic dystrophy.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗
PubMed1990

[Combination effect of caffeine and cisplatin on a cisplatin resistant human lung cancer cell line].

The development of resistance to anti-cancer drugs is a major factor in limiting the response rate of cancer chemotherapy. Several mechanisms of such resistance are reported. Recently, expression of MDR gene and synthesis of p-glycoprotein by the MDR gene was reported as a mode of multi-drug resistance, but the mechanism of the resistance to cisplatinum (CDDP) remains unclear. Detoxification of CDDP, increase of the efflux of the drug and increase of DNA repair are considered to be the mode of CDDP resistance. It is widely documented that caffeine enhances the cytocidal effect of certain anti-cancer agents. The inhibition of DNA repair by caffeine has been considered to be one mechanism which enhances the cytocidal effect of such agents. We conducted the present study to evaluate the combination effect of caffeine and CDDP on the human lung adenocarcinoma cell line PC9/P and its CDDP resistant cell line PC9/R. Cell growth inhibition was measured by clonogenic assay and cell cycle analysis was performed with propidium iodide (PI) stain using flow cytometer (FCM). Caffeine enhanced the effect of CDDP on PC9/P synergistically. However, the combination effect of the two drugs was not apparent on PC9/R. Caffeine decreased G2M accumulation due to CDDP exposure in both cell lines. The data indicate that caffeine does not overcome the resistance of PC9/R, whereas caffeine enters PC9/R. It is suggested that increase of DNA repair might not be a mode of the CDDP resistance of PC9/R.

Adenocarcinoma↗
PubMed1990

The effects of photosensitization by hematoporphyrin derivative on the protein content of cultured human lung cancer cells. A flow cytometric analysis.

In order to study the cytotoxic mechanisms of photodynamic therapy (PDT), the changes in the intracellular content of protein and DNA of cultured human lung cancer cells were examined by flow cytometry using the fluorescent dyes fluorescein isothiocyanate (FITC) and propidium iodide (PI). Immediately after PDT, the protein content increased while the DNA content showed little change. After more than 24 hours, the protein and DNA content were markedly decreased in lethally damaged cells; in sublethally damaged cells, however, the protein content gradually decreased to the level of that before PDT while the DNA content showed little change. These changes in the protein content may reflect the impairment of the plasma membrane function by PDT and its subsequent recovery in some cells.

DNA, Neoplasm↗
PubMed1989

Effects of beta-agonist and antagonist on the pulmonary circulation and the pulmonary pressor response to 5-HT.

We investigated the effects of beta-agonist and antagonist (isoproterenol, propranolol) on the pulmonary circulation and on the pulmonary pressor response to 5-HT in an isolated canine lung lobe. The pulmonary vessels were dilated by isoproterenol at doses up to 200 micrograms, but were constricted by alpha-adrenoceptor stimulation at relatively high doses. The mechanism by which isoproterenol inhibited the 5-HT response is probably related to the stimulation of beta-adrenoceptors at the lower doses and to the stimulation of alpha-adrenoceptors at the higher doses. Propranolol alone had no effect on pulmonary vascular tone, but inhibited the 5-HT response markedly at doses high, possibly by directly blocking the 5-HT receptors.

Adrenergic beta-Agonists↗
PubMed1989

Chemical changes of organic compounds in chlorinated water. XVI. Gas chromatographic-mass spectrometric studies of reactions of tricyclic aromatic hydrocarbons with hypochlorite in dilute aqueous solution.

The products of aqueous chlorination reactions of tricyclic aromatic hydrocarbons (fluorene, carbazole, dibenzofuran, anthracene, phenanthrene and some methyl derivatives) with hypochlorite have been determined by gas chromatography-mass spectrometry. They included chloro-substituted, oxygenated (quinones) and hydroxylated (phenols) compounds, and products of addition which were readily formed at ambient temperature. The extent of the reactions was shown to depend on the chlorine dose, the solution pH, the initial concentrations of both compounds and the structures. Monochlorinated compounds and quinones were shown to be present in chlorinated water under the conditions utilized for water treatment.

Chlorine↗
PubMed1989

Effects of nicorandil and nipradilol on ischemic myocardium in perfused rat heart.

We examined the effect of nicorandil and nipradilol on the ischemic myocardium in the isolated perfused rat heart. The heart was perfused by the working heart technique with an afterload pressure of 60 mm Hg and with a left atrial filling pressure of 9 mm Hg. Ischemia was induced for 20 min by lowering the afterload pressure. The afterload pressure was raised to 60 mm Hg again during reperfusion. Ischemia decreased the pressure-rate product, coronary flow, adenosine triphosphate level and creatine phosphate level, and increased the lactate level. Reperfusion could not restore the pressure-rate product nor the adenosine triphosphate level completely. Nicorandil (5 x 10(-5) and 1.5 x 10(-4) M) or nipradilol (10(-5), 5 x 10(-5) and 1.5 x 10(-4) M) was introduced 5 min before ischemia. Nipradilol preserved the levels of adenosine triphosphate and creatine phosphate after 20 min of ischemia and increased the extent of recovery of the pressure-rate product during reperfusion, whereas nicorandil did not. Nipradilol, but not nicorandil, can protect the myocardium against ischemic damage.

Adenosine Triphosphate↗
PubMed1989

Effect of disopyramide on initiation of atrial fibrillation and relation to effective refractory period.

Electrophysiologic studies were performed before and after intravenous administration of disopyramide (2 mg/kg) to 40 patients with either documented or suspected atrial fibrillation (AF). In control studies, sustained AF (greater than 1 minute), nonsustained AF (1 to 60 seconds) and no AF were found in 14, 18 and 8 patients, respectively. After disopyramide, the ability to initiate AF was totally lost in 18 patients (group A), while 22 patients (group B) showed sustained AF (11 patients) or nonsustained AF (11 patients). The effective refractory period of the atrium was 232 +/- 41 ms in the control study and 266 +/- 49 ms after disopyramide. Atrial functional refractory periods before and after disopyramide were 282 +/- 43 and 317 +/- 48 ms, respectively. The differences and ratios of the refractory periods after and before disopyramide were higher in group A than in group B (p less than 0.001). The prolongation of atrial refractoriness after disopyramide was important to suppress the initiation of AF in group A. In some group B patients, on the other hand, the initiation of AF was promoted after disopyramide. Disopyramide may alter the atrial electrophysiologic substrate required for AF initiation.

Atrial Fibrillation↗
PubMed1989

Release of adenosine and lactate from human hearts during atrial pacing in patients with ischemic heart disease.

Thirty-eight patients treated by atrial pacing were divided into three groups (Group I, patients with neither coronary stenosis nor anginal pain during pacing; Group II, patients with no coronary stenosis but having anginal pain during pacing; Group III, patients with coronary stenosis). The concentrations of adenosine and lactate were measured in the coronary sinus blood and in the arterial blood before, during, and after atrial pacing. During atrial pacing, significant levels of adenosine were released from the heart of patients in Group III, whereas significant lactate release was observed in Groups II and III. In Group II, the concentration of adenosine in coronary sinus blood appeared to increase during pacing, but not significantly. There was no significant correlation between the release of adenosine and that of lactate. A significant release of adenosine due to atrial pacing may be observed only in patients with coronary artery disease.

Adenosine↗
PubMed1989

Flow cytometric analysis of the kinetic effects of cisplatin on lung cancer cells.

The effects of cisplatin on the cell cycle and DNA synthesis of human lung adenocarcinoma cell line PC-9 were examined by flow cytometry. The cellular DNA content and the bromodeoxyuridine (BrdUrd) incorporation rate were measured simultaneously using a monoclonal anti-BrdUrd antibody. Following exposure to cisplatin (1.0 micrograms/ml) for 1 and 24 hr, the bivariate DNA/BrdUrd distributions revealed a delayed S-phase transit and an accumulation of cells in the G2M phase. The BrdUrd-linked green fluorescence intensity continued to decrease with the lapse of time. However, early- and mid-S-phase cells soon recovered DNA synthesis activity, and the former showed higher activity than the control cells. These findings suggested the vigorous DNA synthesis of cells in early S phase. However, for quantitative analysis of chemotherapeutic effects, some problems remained to be resolved regarding the condition for DNA denaturation and its alteration by the agents.

Adenocarcinoma↗
PubMed1989

Single active site mechanism of rabbit liver acid alpha-glucosidase.

An acid alpha-glucosidase was purified from rabbit liver by fractionation with ammonium sulfate, and chromatographies on Sephadex G-100, CM-Toyopearl, Toyopearl HW-55F, and Toyopearl HW-65F column. The resulting preparation showed a single band on polyacrylamide disc gel electrophoresis. The molecular weight was estimated to be 1.03 X 10(4) by SDS-disc electrophoresis. The optimum pH was found to be 4.7. The alpha-glucosidase showed relatively high activity not only toward maltose but also toward alpha-glucans, such as shellfish glycogen, soluble starch, beta-limit dextrin, amylopectin, and amylose. The Km values for maltose and shellfish glycogen were 2.1 and 16 mM (the concentration of non-reducing glucose units), respectively, and the ratio of maximum velocities of hydrolysis of the two substrates was 100:133. The nature of the active site catalyzing the hydrolyses of maltose and shellfish glycogen was investigated by electrophoresis in the presence of urea and by kinetic methods. The purified enzyme was not separated into two components, maltase and glycogen hydrolase, in the electrophoretic gel containing 3 M urea, contrary to the report by Belenki and Rosenfeld ((1972) Biochem. Biophys. Res. Commun. 46, 443-448). In experiments with mixed substrates of maltose and glycogen, the kinetic features agreed very closely with those theoretically predicted for a single site mechanism. The essential ionizable groups, 1 (on the acidic side) and 2 (on the alkaline side), were identified as -COO- and -COOH for the hydrolysis of both substrates. Cations, Na+, K+, Mg2+, were about equally effective for the stimulation of enzyme action on maltose and glycogen.(ABSTRACT TRUNCATED AT 250 WORDS)

Ammonium Sulfate↗