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Biomedical subjects

H Ishihara

Publications and source records attributed to H Ishihara.

At least 451 records · Page 25Linked to original sources
PubMed1990

[Airway hyperresponsiveness and mucus secretion].

A large amount of mucus and mucoid impaction are observed in the autopsied lungs of bronchial asthmatics. It is possible that mucus hypersecretion and accumulation of intrabronchial mucus result in bronchial obstruction and structural bronchial hyperresponsiveness. Bronchial gland plays a main role in human airway secretion. We describe here some results using isolated gland preparation which enable us to examine airway mucus secretion in a well-defined condition. Chemical mediators released from mast cells augment the secretory responses induced by cholinergic nerve stimulation through accelerated acetylcholine release in the nerve terminals. PAF produces an increase in mucus glycoprotein secretion in the presence of platelets mainly through the thromboxane release from platelets. Substance P which is released by an axon reflex in response to various stimuli and inflammations in the airways, also produced an increase in mucus secretion. Epithelial cells release an inhibitory factor to mucus glycoprotein secretion from bronchial glands. Epithelial cell damages due to inflammation in the airways may induced a reduction of the inhibitory factor release in bronchial asthmatics, resulting in mucus hypersecretion.

Asthma↗
PubMed1990

Ceramic interspinous block (CISB) assisted anterior interbody fusion.

Ceramic interspinous block (CISB) assisted anterior fusion system was developed. The system is recommended for patients with symptomatic disc degeneration and destructive lesions of the lumbar spine. One hundred and six patients who underwent CISB-assisted anterior fusion by one doctor (H.T.) from 1981 to 1987 were followed-up 2-6 years after the operation. A comparative study of the results between the CISB-assisted group and the CISB-unassisted anterior fusion group, performed by the same doctor during 1979-1981 for deranged disc, was also done. Satisfactory relief of back and leg pains, marked ADL recovery and early bone union were obtained in all of the CISB-assisted anterior fusion cases. The union rate was 98.9% in the CISB-assisted anterior fusion group, whereas in the CISB-unassisted group, it averaged 79%. The efficacy of CISB for anterior interbody fusion was also verified using a computer simulation. CISB implementation appears to create equalization of stress distribution on the graft-vertebra interface.

Adolescent↗
PubMed1990

[Endocrine and hemodynamic responses to total body hyperthermia in humans].

We investigated effects of total body hyperthermia (TBH) on endocrine and hemodynamic responses. A total of five treatments were performed in five patients with gastric cancer under neuroleptanesthesia with morphine followed by 0.2 to 0.4% enflurane. TBH was extracorporeally induced with veno-venous shunt incorporating with heat exchanger to keep their temperature between 41.5 degrees C and 42.0 degrees C for three hours. The patients were administered angiotensin to maintain tumor blood flow. Lactated Ringer's solution was administered at the rate of 10 to 15 ml.kg-1.hr-1 for five hours. Plasma cortisol levels decreased significantly to about one third of the control value after heating and the levels recovered to the control value after cooling. Plasma norepinephrine level increased significantly to about 7 to 9 times the control value following TBH, but this hormonal response was insufficient to reveal marked direct hemodynamic effects. The magnitude of fall in SVR was more significant in spite of the administration of angiotensin. Cardiac index increased significantly to about 2.0 to 2.6 fold of control value, but mean arterial blood pressure (MAP) decreased significantly to about two thirds to four fifths of the control value. Morphine relieved the hormonal response in ACTH and cortisol strongly, but morphine suppressed hemodynamics by decreasing SVR. Neither norepinephrine released from sympathetic nerve endings nor even 50 to 200 ng.kg-1.min-1 of angiotensin administered failed to restore SVR or MAP during hyperthermia.

Adult↗
PubMed1990

[A carcinosarcoma of the ovary: a case report and a review].

A carcinosarcoma of the ovary, which is a combined epithelial and mesenchymal tumor, is exceeding rare and usually has poor prognosis. Only four known cases, including this case, have been reported in Japan. In our case, after resection a combined chemotherapy consisting of cisplatinum, adriamycin cyclophosphamide and etoposide was administered and the patient had no uneventful postsurgical course.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1990

[Clinical study on total intravenous anesthesia with droperidol, fentanyl and ketamine--1. Introduction].

We have developed a new method of total intravenous anesthesia with droperidol, fentanyl and ketamine and have administered it to more than 400 surgical patients, ranging in ages from 4 to 80 years. Cardiac and neurosurgical patients were excluded. After establishing a routine monitoring, droperidol 0.06-0.1 ml.kg-1 was slowly given. After 5 minutes, fentanyl 1-2 micrograms.kg-1 and ketamine 1.0-1.5 mg.kg-1 were slowly administered intravenously. Trachea was intubated following intravenous succinylcholine. A total dose of 5-15 micrograms.kg-1 of fentanyl was given intravenously with a continuous infusion of ketamine 2 mg.kg-1.hr-1 during surgical procedure. Air and O2 (FIO2 0.30-0.35) were given and muscle relaxation was achieved with necessary dose of intravenous pancuronium or vecuronium and no inhaled anesthetic was given. Total intravenous anesthesia has many advantages such as no air pollution in the operating theatre, empty bowels, no organ (hepato-renal) toxicity, good peripheral perfusion and low cost, while this method has several disadvantages to overcome such as hypertension. There are many anesthetic agents for total intravenous anesthesia. However, sufentanil, alfentanil and propofol are not available. Droperidol, fentanyl and ketamine are the best combination for this purpose in Japan so far.

Adolescent↗
PubMed1990

[Anesthetic management of a patient with Sjögren's syndrome and pulmonary fibrosis].

We described an anesthetic management of a 63 year old man complicated with Sjögren's syndrome and pulmonary fibrosis. Sjögren's syndrome is characterized by pathological dryness of the mouth, cornea and other exocrine glands. Anesthesia was induced with thiopental and the trachea was intubated smoothly following intravenous succinylcholine. Anesthesia was maintained with enflurane in nitrous oxide and oxygen. Intraoperative muscle relaxation was adequately obtained by pancuronium. Before and during anesthesia, atropine and other drying agents were avoided. Physiological saline solution was instilled on the eyes every ten minutes against dryness. A heat and moisture exchanger (Humi-Vent) was used to maintain high moisture of the respiratory tract. Anesthesia was carried out successfully.

Anesthesia, Inhalation↗
PubMed1990

[The changes in total body water in patients with prolonged anesthesia and surgery].

We studied the influence of prolonged anesthesia and surgery on total body water (TBW) with tetrapolar bioelectrical impedance analysis (BIA). Eight patients who underwent prolonged anesthesia were selected as the subjects of the study and were compared with nine patients who underwent surgery of less than 3 hours. Plasma hormone concentrations were also examined. In the prolonged anesthesia patients, TBW increased significantly as compared with those of the patients who underwent short surgery (P less than 0.05). TBW showed the most remarkable increase on the first post operative day. Plasma ADH and aldosterone concentrations increased in the patients of both groups. However, we could not find a significant relationship between TBW and plasma hormone concentrations. BIA seems to be a useful method to estimate TBW during perioperative periods. However, further detailed investigation would be necessary to obtain a reliable technique in such an unstable condition.

Adult↗
PubMed1990

[Simultaneous operation of WPW syndrome combined with mitral regurgitation caused by infective endocarditis].

A case of WPW syndrome combined with mitral regurgitation caused by infective endocarditis underwent surgical division of accessory pathway and mitral valve replacement preserving posterior leaflet simultaneously. A 56-years old woman suffered atrial fibrillation with pseudo VT and cardiac failure caused by mitral regurgitation. Electro-physiological study (EPS) revealed accessory pathway in postero-lateral wall in left atrium and atrio-fascicular pathway like James bundle in AV node. ECHO cardiography showed mitral valve prolapse and severe regurgitation. Accessory pathway was divided surgically and deep freeze coagulation was followed. Perforation of anterior leaflet and chordal rupture of posterior leaflet caused by infective endocarditis were repaired by annuloplasty (Kay and McGoon method) at first, but regurgitation retained moderately. After re-clamping of aorta, mitral valve was replaced with prosthesis (SJM 29 mm) preserving posterior leaflet. Postoperative examination revealed division of accessory pathway and no regurgitation of mitral prosthesis.

Endocarditis, Bacterial↗
PubMed1990

[Respiratory gas exchange during total body hyperthermia in man].

Respiratory gas exchange was evaluated using indirect calorimetry during total body hyperthermia (TBH) in 7 postoperative patients with disseminated gastric cancer to the peritoneal cavity. TBH was induced using veno-venous bypass and extracorporeal circuit incorporating a heat exchanger to keep pulmonary arterial temperature 42 degrees C. The high temperature was maintained for 3 hours under general anesthesia with droperidol (0.15 mg.kg-1), morphine (1 mg.kg-1) and enflurane (less than 0.5%). Oxygen consumption (VO2) was also calculated using the Fick equation and thermodilution cardiac output. Hyperthermia for three hours increased both VO2 and carbon dioxide output (VCO2) values to 1.5 times as compared to the control values before heating, respectively. VO2 values measured by indirect calorimetry correlated well with the values calculated from the Fick equation when respiratory and cardiovascular system were relatively stable during the procedure. Gradual but statistically insignificant increase in respiratory quotient was observed after recooling started. These results suggest that indirect calorimetry was valuable to measure respiratory gas exchange continuously during hyperthermic state as well as normothermic state. However, RQ value observed in the present study may be modified by several factors including lactate accumulation in the blood, and may not reflect substrate utilization during the hyperthermic state.

Adult↗
PubMed1989

A novel phospholipase A2 associated with nuclear matrix: stimulation of the activity and modulation of the Ca2+ dependency by polyphosphoinositides.

Neutral phospholipase A2 activity, which hydrolyzed phosphatidylcholine and phosphatidylethanolamine with the same efficiency, was identified in the nuclear matrix prepared from purified nuclei of rat ascites hepatoma cells (AH 7974). The enzyme activity was optimal at pH 7.0 and required Ca2+ absolutely. Concentrations of Ca2+ for a maximal and a half-maximal activation were 1.10(-2) and 1.10(-3) M, respectively, and little activity was detected at Ca2+ concentrations lower than 1.10(-5) M. Addition of acidic phospholipids markedly stimulated the enzyme activity, and further, lowered the minimum Ca2+ concentration required for activation. In particular, the polyphosphoionositides phosphatidylinositol 4-monophosphate and 4,5-diphosphate were most effective. These two polyphosphoinositides lowered the Ca2+ concentration required for half-maximal activation to 10(-5) M and dramatically stimulated the activity at that Ca2+ concentration (greater than 30-fold). The neutral phospholipase A2 activity such as characterized in the present study was very low in the other subcellular fractions including mitochondria, microsome, plasma membrane and cytosol.

Animals↗
PubMed1989

Calyculin A and okadaic acid: inhibitors of protein phosphatase activity.

Calyculin A and okadaic acid induce contraction in smooth muscle fibers. Okadaic acid is an inhibitor of phosphatase activity and the aims of this study were to determine if calyculin A also inhibits phosphatase and to screen effects of both compounds on various phosphatases. Neither compound inhibited acid or alkaline phosphatases, nor the phosphotyrosine protein phosphatase. Both compounds were potent inhibitors of the catalytic subunit of type-2A phosphatase, with IC50 values of 0.5 to 1 nM. With the catalytic subunit of protein phosphatase type-1, calyculin A was a more effective inhibitor than okadaic acid, IC50 values for calyculin A were about 2 nM and for okadaic acid between 60 and 500 nM. The endogenous phosphatase of smooth muscle myosin B was inhibited by both compounds with IC50 values of 0.3 to 0.7 nM and 15 to 70 nM, for calyculin A and okadaic acid, respectively. The partially purified catalytic subunit from myosin B had IC50 values of 0.7 and 200 nM for calyculin A and okadaic acid, respectively. The pattern of inhibition for the phosphatase in myosin B therefore is similar to that of the type-1 enzyme.

Alkaline Phosphatase↗
PubMed1989

N-acetylneuraminic acid and N-glycolylneuraminic acid in glycopeptides of colonic tumor and mucosa in rats treated with carrageenan and 1,2-dimethylhydrazine.

N-linked glycopeptides were prepared from colonic tumor (adenocarcinoma) and mucosa in rats treated with carrageenan, an indigestible polysaccharide, and 1,2-dimethylhydrazine. Sialic acids, N-acetylneuraminic acid and N-glycolylneuraminic acid, obtained by acid hydrolysis of the glycopeptides were determined by HPLC. The N-acetylneuraminic acid/N-glycolylneuraminic acid ratio in colonic tumor was 25.2, while each treated mucosa had the values between 0.29 and 0.55. Thus, necessity which observes the qualitative change of sialic acid in malignant transformation was suggested.

1,2-Dimethylhydrazine↗
PubMed1989

Direct write-out of particle size distribution of inhaled aerosol deposition using a laser scattering method.

We developed a device to measure inhaled aerosol deposition in the lung from the difference in particle size distribution of the aerosol during inspiration and expiration. To measure quantity and size distribution of nebulized aerosol particles directly at the subject's mouth we used a He-Ne gas laser scattering technique. To test the reliability of the instrument, we measured particle size distributions of saline aerosols generated by four kinds of nebulizer and compared the results with those from a Malvern 2600D particle sizer as a standard of comparison. Measured mass median diameters (MMDs) were almost identical by both methods. Aerosol deposition in five normal subjects showed that the deposition fraction of the particles increased the larger the particle sizes inhaled. The data suggest that the newly developed aerosol spectrometer can directly analyze aerosol particle size distribution at the mouth during tidal breathing, and that the instrument is useful for quantitative analysis of aerosol inhaled and of inhaled aerosol deposition.

Aerosols↗
PubMed1989

Water diffusion pathway, swelling pressure, and biomechanical properties of the intervertebral disc during compression load.

The behavior of water in the intervertebral disc of pig tail and its physiologic and biomechanical properties were investigated in relation to compression load. The water content, chemical composition, and swelling pressure in the intervertebral disc were measured, and the mechanism of the generation of the swelling pressure in relation to compression load stress was studied. The swelling pressure, through regulation of the water content of the disc and the resistance of the external load, differs with the region of the intervertebral disc. In the nucleus pulposus and the inner layer of the anulus fibrosus, the swelling pressure rises in proportion to the load, but few changes occur in the outer layer of the anulus fibrosus, and the constant pressure environment is thus maintained. The tritiated water (3H2O) uptake of the disc under various loads was measured. The molar partition coefficient of tritiated water is almost equal to 1 even under a compression load, which suggests that water is freely exchangeable. The diffusion of 3H2O in the intervertebral disc was traced using two pathway models: the perianular route and the end-plate route. The diffusion of water in the unloaded disc for both uptake and washout was about 2 to 3 times larger in the perianular route than in the end-plate route. Under load, the water diffusion was inhibited in both pathways. The relation between the load and displacement revealed viscoelastic properties indicating creep and stress relaxation. Young's modulus and the stiffness increased with a rise in load speed.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗