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Biomedical subjects

S Miyazaki

Publications and source records attributed to S Miyazaki.

At least 559 records · Page 31Linked to original sources
PubMed1990

Changes of left ventricular diastolic function in exercising dogs without and with ischemia.

Left ventricular (LV) diastolic function in the absence and presence of regional ischemia was examined in eight conscious dogs chronically instrumented with ultrasonic devices for measuring LV wall thickness and volume. During treadmill exercise, ischemia was induced (hydraulic occluder) to produce less than 10% systolic wall thickening in the ischemic zone. LV filling was assessed by the peak filling rate (PFR), mean filling rates in the first and second halves of filling (mFR1 and mFR2), an early filling index from mitral valve opening to minimal diastolic pressure (PDm), and the percentage of atrial filling. Also, LV relaxation (tau) and wall thinning rates during isovolumetric relaxation and the first and second halves of the filling phase were assessed. During control exercise without ischemia, PDm decreased by 2.61 mm Hg (p less than 0.05) to -1.1 mm Hg and there was a downward shift of the entire LV diastolic pressure-volume (P-V) curve. The LV relaxation rate, PFR, mFR1, and mFR2 were enhanced. Early filling was increased by 116%, the percentage of atrial filling by 118%, and overall diastolic filling by 23% despite a 63% decrease in the filling period. During ischemic exercise, systolic function was depressed compared with the resting state, PDm increased by 4.84 mm Hg (p less than 0.005) associated with a pronounced rightward and upward shift of the early portion of the P-V curve. LV relaxation rate, PFR, and mFR1 were reduced, the early filling index fell sharply by 62% but percentage of atrial filling was unchanged, while overall diastolic filling decreased by 30%. The thinning rate of the control wall was enhanced, whereas that of ischemic wall was depressed. Multiple factors contributed to the markedly impaired early and overall diastolic LV filling during ischemia, including impaired systolic function, reduced relaxation rate, nonuniformity of wall motion, an upward shift of the early diastolic P-V curve, and absence of a compensatory increase in late diastolic filling.

Animals↗
PubMed1990

The effect of pravastatin in relation to low density lipoprotein receptor activity.

Pravastatin, an inhibitor of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase, suppresses new synthesis of cholesterol via HMG-CoA in hepatocytes. As a result, low density lipoprotein (LDL) receptor activity in the liver is enhanced, which leads to lowering of plasma cholesterol. Inhibitors are shown to be effective in heterozygous familial hypercholesterolaemia (FH). Although FH heterozygotes are defined genetically as possessing half the normal LDL receptor activity, some heterogeneity of LDL receptor activity is observed in these patients. To see whether the effect of an inhibitor is related to LDL receptor activity in each patient, pravastatin was administered to 7 FH heterozygotes for 3 months at a daily dose of 10 mg; their mean LDL receptor activities measured before the therapy were 45.0 +/- 9.9% of the normal control. After medication, mean serum total cholesterol decreased from 349.0 to 279.7 mg/dl (p less than 0.05), and LDL-cholesterol decreased from 272.6 to 207.7 mg/dl (p less than 0.05). A significant correlation between the initial LDL receptor activity and the effect of pravastatin was not proved. However, the pre-treatment level of LDL-cholesterol was positively correlated (r = 0.795) with the absolute decrement of LDL-cholesterol after 3 months (p less than 0.05). This implies that the more LDL-cholesterol was elevated, the more pravastatin was effective.

Adult↗
PubMed1990

Effective purification of human chorionic gonadotropin and its subunits from pregnant women's urinary peptides absorbed on reverse-phase resin.

Human chorionic gonadotropin (hCG) was extracted and purified by reverse-phase resin (Sepralyte C8 resin) adsorption and Sephadex G-100 column chromatography from urine of pregnant women. Approximately 15000 IU of hCG was recovered from 1000 ml of urine by C8 resin adsorption. hCG from the gel-filtration step stimulated testosterone production in rat Leydig cells and had a specific activity of approximately 8000 IU/mg, a value which was higher than those of commercial hCGs. Furthermore, hCG purified to near-homogeneity was separated effectively into its subunits by reverse-phase high-performance liquid chromatography using an acetonitrile gradient in the presence of 0.1% trifluoroacetic acid with no special pretreatment for dissociation of subunits. The separated subunits were able to re-associate. The techniques used are simple and may be suitable for not only laboratory but also industrial production of hCG and its subunits.

Animals↗
PubMed1990

Kinetic analyses of creatine kinase release patterns in patients with acute myocardial infarction undergoing emergency coronary arteriography.

To quantify the effects of early reperfusion on the size of infarcts, an enzyme indicator was developed: myocardial creatine kinase (CK) release rate (kr), based on a compartmental kinetics model. In 59 patients with acute myocardial infarction (MI) who received intracoronary thrombolysis therapy in the acute phase, the kr showed a good correlation with the flow condition of infarct-related coronary artery and the time required to reach peak enzyme activity. Apparent serum CK disappearance rate (kd') was estimated by using the method of Norris. The kd' was significantly underestimated in patients without reperfusion, suggesting the presence of prolonged enzyme release from the infarcted area. In 22 of 59 patients, who had a first acute anterior MI (left anterior descending arterial lesion), the correction of cumulative enzyme release by myocardial enzyme release (kr) resulted in a closer correlation with chronic phase left ventricular function. Thus, kinetic analyses of serum enzyme release provide a useful means to estimate the infarct size during intracoronary thrombolysis therapy.

Adult↗
PubMed1990

Effects of uvulopalatopharyngoplasty on sleep architecture and patterns of obstructed breathing.

In this retrospective study, 72 obstructive sleep apnea patients with polysomnograms taken before and after uvulopalatopharyngoplasty were evaluated. Postoperatively, there was a significant improvement of sleep architecture and respiratory indices. In addition, a second group of 17 patients also had position recordings with their polysomnograms. Time spent in supine and lateral sleep positions changed postoperatively. There was significant decrease of the apnea plus hypopnea index in the lateral position. This study indicates that there is significant improvement of sleep architecture and respiratory indices in the majority of patients after uvulopalatopharyngoplasty, particularly in the lateral sleep position.

Female↗
PubMed1990

Highly sensitive microplate-ELISA for angiotensin I using 3,3', 5,5'-tetramethylbenzidine.

A microplate-ELISA was established for angiotensin (Ang) I using Ang I-peroxidase conjugate, antiAng I antibodies which could distinguish Ang I from Ang II and Ang III, and 3,3', 5,5'-tetramethylbenzidine. Ang I could be quantified in amounts as low as 1 pg by the spectrophotometric method. The present assay system was the most sensitive and rapid in all Ang I assay systems described so far. The assay system was applicable to determination of Ang I concentration in human plasma and abdominal fluid.

Adult↗
PubMed1990

Resection of high-cervical paraganglioma with cervical-to-petrous internal carotid artery saphenous vein bypass. Report of two cases.

Two patients with large high-cervical paragangliomas were treated with radical resection and placement of a cervical-to-petrous internal carotid artery saphenous vein bypass. The high-cervical and infratemporal segments of the internal carotid artery engulfed within the tumor were resected and successfully replaced with a saphenous vein interposition graft. The postoperative course was uneventful in both cases and follow-up angiography revealed satisfactory reconstruction of the high-cervical and infratemporal skull base carotid artery. The operative technique, indications, and potential future applications of this newly developed skull base bypass procedure are discussed.

Adult↗
PubMed1990

Percutaneous retrogasserian glycerol injection in the management of trigeminal neuralgia: long-term follow-up results.

The results in 122 patients with trigeminal neuralgia who underwent percutaneous retrogasserian glycerol injection are presented. Eighty patients were followed from 38 to 54 months. The recurrence rate at 54 months was 72% (Kaplan-Meier analysis), and the median pain-free interval was 32 months. Complications associated with the procedure were significantly high: 63% of the patients had definite hypesthesia of the face and 29% had unpleasant dysesthesias, including two cases of anesthesia dolorosa. Sensory disturbances were most frequent in patients who had received a previous alcohol block procedure. Among the patients without previous peripheral procedures, 50% developed sensory disturbances. Because of the high rates of recurrence and sensory disturbances, the authors prefer microvascular decompression for the management of trigeminal neuralgia.

Adult↗
PubMed1990

Topostin, a novel inhibitor of mammalian DNA topoisomerase I from Flexibacter topostinus sp. nov. I. Taxonomy, and fermentation of producing strain.

We found a new inhibitor of mammalian DNA topoisomerase I, named topostin, from a bacterial culture. The bacteria was identified as Flexibacter topostinus sp. nov., B-572. Morphological and physiological characteristics, and utilization of sugars were examined. Comparison of the strain with known species of the genus Flexibacter was made and indicates that the strain is a new species of the genus Flexibacter. The bacteria produced the inhibitor in parallel with their growth up to 72 hours.

Culture Media↗
PubMed1990

Topostin, a novel inhibitor of mammalian DNA topoisomerase I from Flexibacter topostinus sp. nov. II. Purification and some properties of topostin.

We describe the isolation of inhibitors of mammalian DNA topoisomerase I, named topostins, from a culture broth of Flexibacter topostinus sp. nov. and some properties of the inhibitors. Topostins A1, A2 and B were isolated by differential solubility in solvents, adsorption chromatography on silica gel and gel filtration on a Sephadex LH-20 column. Topostins A1, A2 and B had specific activities of 4,700, 16,000 and 22,000 U/mg, respectively. The most active metabolite topostin B comprised two components with MW of 567 and 553 in an equimolar ratio.

Chromatography, Affinity↗
PubMed1990

Three patients who spontaneously developed persistent hypothyroidism during or following treatment with antithyroid drugs for Graves' hyperthyroidism.

Three patients with Graves' disease who spontaneously developed hypothyroidism after treatment with antithyroid drugs are described herein. Patient 1 developed a painful tender thyroid enlargement with a fever and accelerated erythrocyte sedimentation rate when she was receiving maintenance therapy with methimazole, and she progressed to persistent hypothyroidism with increased titers of antithyroglobulin and antimicrosomal antibodies and marked reduction of goiter size within the subsequent 2 months. Thyroid-stimulating hormone-binding inhibitory immunoglobulins (TBIIs) and thyroid stimulation-blocking antibody (TSBAb) were absent when she was hypothyroid. Hypothyroidism probably resulted from autoimmune thyroid destruction due to subacute aggravation of Hashimoto's thyroiditis. During the clinical course of patient 2, accelerated erythrocyte sedimentation rate and later transient increases of antimicrosomal and antithyroglobulin antibody titers were observed repeatedly (four times), and she finally fell into overt hypothyroidism. She also had negative results of tests for TBII and TSBAb. Her hypothyroidism appeared to result from repeated thyroid destruction due to aggravation of Hashimoto's thyroiditis. Patient 3 fell into hypothyroidism when receiving a small dosage of methimazole. The TBII and TSBAb were strongly active when she developed hypothyroidism, which thus seemed to be due to blocking antibody. Patients with Graves' hyperthyroidism may eventually progress to hypothyroidism later by several different mechanisms. Severe and sudden or slowly repeated thyroid destruction due to aggravation of Hashimoto's thyroiditis is one mechanism. Another may be the appearance of a blocking antibody to the TSH receptor.

Adult↗
PubMed1990

[Role of polymorphonucleocyte-produced leukotriene B4 in Kawasaki disease].

It is postulated that inflammatory cells play an important role in the process of developing vasculitis in Kawasaki Disease. LTB4, a 5-lipoxygenase product of arachidonic acid is one of the most potent chemoattractants to inflammatory cells and is produced in large amounts by PMNs. We investigated the role of PMN-derived LTB4 in Kawasaki Disease. Isolated PMNs were obtained from 19 Kawasaki disease patients in three different phases of the illness, (acute phase: 0-12th day, convalescent phase: 13-29th day, restored phase: greater than 30th day). LTB4 synthesis in the convalescent phase was 26.43 +/- 4.2 ng/5 x 10(6) cells, which was significantly higher than those in the acute and restored phases (11.90 +/- 1.91, 13.87 +/- 1.86 ng) and also higher than that in the control subjects (10.65 +/- 1.26 ng: p less than 0.05). No differences were found between two groups with or without coronary lesions. The results imply that activated PMNs during the convalescent phase of illness produce larger amount of LTB4 which may participate in the development of inflammatory process of the disease and that PMN-derived LTB4 plays no significant roles in the development of coronary lesions.

Aspirin↗
PubMed1990

Pharmaceutical application of biomedical polymers. XXIX. Preliminary study on film dosage form prepared from chitosan for oral drug delivery.

The potential of chitosan films containing diazepam as an oral drug delivery was investigated in rabbits. The results indicated that a film composed of a 1:0.5 drug-chitosan mixture might be an effective dosage form that is equivalent to the commercial tablet dosage forms. The ability of chitosan to form films may permit its use in the formulation of film dosage forms, as an alternative to pharmaceutical tablets.

Animals↗
PubMed1990

[Evaluation of pluronic F127 as a base for gradual release of anticancer drug].

The property of pluronic F127 (PLF) as a base for an anticancer agent, mitomycin C (MMC) was evaluated. A weighed amount of PLF and MMC were slowly added to cold water and mixed completely. The solution was warmed to 37 degrees C and MMC containing PLF gel was formed. The cumulative amount of MMC which was released from the gel during a 3-hour period was calculated. 5.5 percent of MMC was released from PLF-MMC gel which contained 20 or 25% PLF and 3.8% MMC from PLF-MMC gel containing 30% PLF. Intraperitoneal (i.p.) administration of large amount of PLF gel alone in rabbits or mouse revealed severe hepatorenal toxicity, and acute i.p. administered LD50 of PLF was supposed to be between 1.7 g and 5.0 g/kg body weight in mouse. Further evaluation of gradual releasing property of PLF is needed.

Animals↗
PubMed1990

[The influence on the dental staff by having the patient's mother beside the dental chair].

This research concerns the reasons for having the mother located beside the dental chair and the influence on the dental staff by the patient's mother. The subjects were a total of 390 persons, of which 100 children, 100 mothers, 100 doctors and 90 assistants. A total of 20 items consisting of 10 items from the psychological test and 10 items from the dental charts. Discriminant analysis was carried out according to the second class of Hayashi's quantifying theory concerning the entrance into the dental office or non-entrance chosen as an external criterion. The mothers answered questions on the psychological test about the psychological distance between the mother and the child. They also answered the questionnaires about their psychological process. The doctors and assistants answered concerning to "manifest anxiety scale" and questionnaires about their psychological process. The results are summarized as follows: 1. The ratio of the distinctive efficiency of external criteria to the entrance or non-entrance was found to have a high correlative coefficient, 0.70. When the factors mentioned above are ranked according to the external criteria the order is as follows: "treatment experience of the child", "adaptation degree to the treatment of the child", "birth order of the child", "clinical experience of the doctor", "the child's age". 2. The psychological distance of "the mother waiting out of the dental office" is longer than the distance of "the mother in the dental office". 3. The mother's presence in the dental office had some psychological influence on the doctor and the assistant.

Adult↗
PubMed1990

[A study of communication and behavior management in pediatric dentistry. Approach to the child using the fairy tales].

There were a total of 100 subjects, of which 50 were children and 50 were mothers. The first time, the doctor lends the child the fairy tale book. The second time, the child is treated under the audio-analgesia with the same fairy tale book and the child borrows on other fairy tale book. The third time, the child is also treated under the audio-analgesia. The child, the mother and the doctor answered the questionnaires. Changes in internal behavior were observed by polygraph system. The subjects comprised a total 13 children (4 to 6 years), of which 6 were males and 7 were females. The first time, the emotional reactions were observed when the subjects were stimulated by the engine, the turbine and the crying for 10 seconds each. The Second and third time, the emotional reactions were also observed under the audio-analgesia. The change ratios were analyzed with respect to Plethysmogram, Respiration Curve and Galvanic Skin Reflex. The results are summarized as follows: 1. 91.8% of the parents answered "I would like my children to be treated under the audio-analgesia using fairy tales." 2. 73.5% (2nd time) and 80% (3rd time) of the children answered "The treatment has been pleasant." 3. 61.2% (2nd time) and 64% (3rd time) of the doctors answered "The anxiety and fear was reduced by the approach." 4. With the engine stimulation, the emotional reaction decreased in the order, of the 1st time greater than 3rd time greater than 2nd time. There were significant differences between the 1st time and the 2nd time, and also between the 1st time and the 3rd time.(ABSTRACT TRUNCATED AT 250 WORDS)

Audioanalgesia↗
PubMed1990

[Cancer cells in the portal and hepatic veins of resected specimens of hepatocellular carcinomas].

After injecting 100 ml of a saline solution into the hepatic artery of 27 livers evidencing a hepatocellular carcinoma, samples from the resected livers were collected through the portal and the hepatic vein. Cancer cells were detected in 4 out of 27 samples from the portal vein and in 1 out of 19 samples from the hepatic vein, and the total number of positive cases were 4. Further, tumors over 5 cm in diameter showed a tendency of flowing cancer cells into the portal vein. Four positive cases had an intrahepatic and a distant metastasis within one year of their operation and two of these patients died.

Aged↗