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Biomedical subjects

H Murakami

Publications and source records attributed to H Murakami.

At least 613 records · Page 34Linked to original sources
PubMed1989

Effects of norepinephrine and angiotensin II on plasma atrial natriuretic peptide concentration in humans.

To clarify the effects of norepinephrine and angiotension II (Ang II) on plasma atrial natriuretic peptide (ANP), both pressor substances were infused into normal volunteers, and plasma ANP levels and venous return were determined. When norepinephrine infusion elevated mean arterial pressure by 15 mm Hg, a transient increase of plasma ANP was observed. However, Ang II infusion showed no effect on plasma ANP levels, even though it also elevated arterial pressure. Superior vena cava flow and left atrial area, which were determined echocardiographically as the index of venous return, increased in the norepinephrine infusion study. However, in the study of Ang II infusion, there was no significant change in either superior vena cava flow or left atrial area. From these results, it was concluded that increased left atrial volume due to increased venous return is the major factor inducing ANP release in norepinephrine infusion.

Adult↗
PubMed1989

[Study on the physico-chemical properties of fluoride gel in application of freeze-drying gelatin gel method (tray method)].

As a means of studies of securing freeze-drying method by application of tray for prevention of white spots, decalcification and secondary caries of enamel, which may develop during and after orthodontic treatment, comparison and review were made on physico-chemical properties of fluoride gel to be used for gelatin gel method and freeze-drying gelatin gel method (control group gel and experimental group gel), and the following results were obtained: 1. Physical properties As the results of naked-eye observations, morphological observations through scanning electron microscope and measurements of gelly strength and viscosity, no distinct difference between control and experimental group gel was noted. 2. Chemical properties The qualitative analyses of fluoride ion with ion chromatogram and pH measurement were carried out, and consequently experimental group gel indicated similar values to control group gel. From the foregoing results, it was learned that no significant difference in their physico-chemical properties was clearly confirmed between control and experimental group gel, and it was suggested that similarly to control group gel, experimental group gel would be an effective gel substance as gel media for the formation process of fluorapatite or the reinforcement method of tooth enamel.

Fluorides, Topical↗
PubMed1989

[Myeloid crisis of chronic myelogenous leukemia showing dramatic response to mithramycin and hydroxyurea combination].

After 4 years of chronic phase, a 22-year-old female with Ph1 (+) chronic myelogenous leukemia developed myelomonocytic crisis. On admission, her Hb was 9.9 g/dl, Plt 4.1 x 10(4)/microliters, WBC 138,000/microliters with 16.5% blasts. Bone marrow contained 38% blasts. She received a combination chemotherapy of mithramycin and hydroxyurea, as reported by Koller et al. Dose of mithramycin was reduced to 20 micrograms/kg. Following 1st and 2nd infusions of mithramycin, severe nasal bleeding was seen. Prednisolone 10 mg/day was given from the 3rd dose of mithramycin with apparent hemostatic effects. Calcium gluconate 3 g/day was administered concomitantly. Her disease responded promptly to this treatment and hematological remission was achieved.

Adult↗
PubMed1989

[Enhancement of enamel crystallinity with gel method during orthodontic treatment. The 2nd report: application of micro-area X-ray diffraction method].

This study is to review an effect on the improvement of enamel crystallinity with gel method in the course of orthodontic treatment by applying gelatin gel method (group II) as well as silica-hydro gel method (group I) to bracket-bonded enamel surfaces of extracted teeth and for a relative review, the chopped cross sections of the above teeth were analyzed by the method of micro area X-ray diffraction. The results obtained were as follows: 1. As a result of identifying by the method of microarea X-ray diffraction, the present of hydroxyapatite, Ca5(PO4)3OH and fluorapatite, Ca5(PO4)3F was recognized at any section of every group. 2. In making a relative study of the variation of line profile and peak shift, an outstanding difference was not acknowledged in line profile, however, peak shift in the direction of high angle side was indicated on the experimental side of each group and a tendency for peak shift was more noticeable near by enamel cuticle. At boundary sites and on the control side, the variation was only shown in one part of group II. Also a tendency for peak shift in the direction of high angle side was recognized in group I rather than in group II. From the foregoing results, it was found to be effective to improve tooth substance of the bracket-bonded enamel and in that event, the silica-hydro gel method was suggested to be superior to the gelatin gel method. Also with the regard to the bracket-bonded sides, tooth substance was noticeably improved at enamel cuticle but not sufficiently improved at sites underneath the brackets and at boundary sites of the both, therefore, one of the future subjects would be to review such areas.

Apatites↗
PubMed1989

[Influence of cardiopulmonary bypass on plasma lipid peroxides].

In 22 patients who underwent cardiac surgery with cardiopulmonary bypass (CPB), we studied the influence of CPB on the level of lipid peroxides (LPO) in plasma by means of measuring the time course of plasma LPO level during and after CPB. We expressed LPO level, which was measured by thiobarbituric acid reaction, as the level of malondialdehyde. In our preliminary study, it was found necessary to correct the plasma LPO level diluted by priming fluids of CPB machine and the concentration of plasma protein was fitted for its correction. In the following study, we used the plasma LPO level corrected by the concentration of plasma protein. LPO were significantly decreased since the initiation of CPB (1.669 +/- 0.208 versus pre-CPB 1.785 +/- 0.158 log nmol MDA/gm protein, p less than 0.05) to the post CPB 30 minutes, except around 60 minutes after initiation of CPB (1.735 +/- 0.242 log nmol MDA/gm protein, p greater than 0.05). As the initial change (the values at 30 minutes after CPB initiation) may express the effect of CPB directly in this time course of LPO, we analyzed the initial change on different background factors. By ordinary analysis of the initial change, as to the effect of type of disease (congenital and acquired), LPO were decreased in the acquired group (1.617 +/- 0.197 versus pre-CPB 1.779 +/- 0.163 log nmol MDA/gm protein, p less than 0.05). At that time the acquired group was significantly different from the congenital group (1.799 +/- 0.191 versus pre-CPB 1.800 +/- 0.157 log nmol MDA/gm protein, p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1989

[A clinicopathological study of recurrent gastric cancer cases treated by a resection of the remnant stomach].

Seventeen cases of a recurrent gastric cancer that were treated by a resection of the remnant stomach have been studied retrospectively. For first management 12 cases were given a Billroth 2 procedure, 4 cases a Billroth 1 procedure and 1 case a fundectomy. For the recurrent cancer, 13 cases were given a total resection of the gastric remnant and 4 cases a partial resection. The overall mortality rate was 12% and the survival rate was 58% at 1 year, and 8% at 5 years. We thus have concluded that a resection of the remnant stomach should be carried cut in cases of a recurrent gastric cancer whenever possible.

Adult↗
PubMed1989

[Dental application of superplastic forming for titanium complete denture bases].

In order to investigate the application of superplastic in forming dental prosthesis, the sheets of titanium and its alloy were deformed to the complete denture bases by using a trial hot press and ceramic die. The results are summarized as follows: 1) By the hot press. It was possible to deform the sheet at a deformation speed ranging from 1 x 10(-3) to 3 x 10(-2) mm/sec at a temperature up to 900 degrees C under a vacuum down to 10(-3) Torr. 2) The trial ceramic die was prepared by sintering the green of the CaO-TiO2-ZrO2-MgCl2 system at 1150 degrees C for 6 hours in the atmosphere. The compressive strength, the thermal expansion, and the surface roughness of the test piece of the die were 11 kg/cm2, 0.8%, Ra = 1.4 microns and Rz = 6.8 microns, respectively. 3) Both the sheet of pure chemical titanium and commercial superplastic titanium alloy Ti-6Al-4V were deformed under the conditions of about 0.1 mm/min, 850 degrees C, and 10(-3) Torr. The deformed surface of the complete denture bases appeared to be nearly the same metallic color of each raw sheet and the pattern was the same as the detail of the die. The oxygen enriched layer of the article determined by EPMA was far thinner than that of a dental cast.

Dental Alloys↗
PubMed1989

[Ultrastructural and immunohistochemical studies of regenerating epithelium-stroma junctions of rat tracheal epithelium after mechanical injury].

Regeneration of the rat tracheal epithelium following mechanical injury was studied by electron microscopy and immunohistochemistry. The first event that occurred following the injury was rapid flattening of the viable epithelial cells of the wound margin and their migration to the injured area. In the early stage, the regenerating epithelium changed from a simple squamous to a multilayered structure, or typical squamous metaplasia. Immunohistochemically, keratin was detected in the regenerating cells, and actin was present linearly along the basal cell membrane of the migrating epithelial cells. Fibronectin also appeared in the wounded stroma immediately beneath the migrating epithelium until the migration was completed. Both laminin and type IV collagen reappeared under the regenerating epithelium from the wound margin after the migration was completed in the middle stage. Ultrastructurally, fibronexus-like structures and so-called anchoring filaments appeared in the epithelium-stroma junction before hemidesmosomes, basal lamina and anchoring fibrils reappeared. We consider that both fibronexus-like structures and anchoring filaments are responsible for the initial adhesion of the regenerating epithelium to the underlying connective tissue.

Animals↗
PubMed1989

A practical method for estimating total oxygen uptake during exercise in elderly men.

In the present study, after a total of 51 observations of a 30-min cycle exercise performed by 17 men ranging in age from 60 to 65 years, the following formula was finally obtained for evaluating total O2 uptake (TVO2) during exercise: TVO2 (ml.kg-1) = SR125 X (49.5 X mean HR + 3760) X THB X 10(-4), where mean HR and THB are mean heart rate (beats.min-1) and total heart beats in exercise, respectively, and SR125 is the slope of the regression line of accumulative O2 uptake on accumulative heart beats during exercise at a mean HR of 125 beats.min-1. SR125 was significantly correlated not only to predicted VO2max but also score (X) in the step test for 2 min (25 steps.min-1 on 35-cm stool), yielding a formula, SR125 = -0.00131X + 0.3660. Consequently, both formulae indicate that total O2 uptake of any exercising elderly man can be estimated from total heart beats and mean HR during exercise, regardless of intensity of exercise when SR125 was determined by the step test. The discrepancy between total O2 uptake evaluated by the estimation method for elderly men and that determined by the Douglas bag method was 10.2 +/- 7.3%.

Aged↗
PubMed1989

[Basic studies on hard direct reline resins. Part 1. Adhesive strength].

Direct relining methods has come to occupy an important position in removable denture prosthodontics. The purpose of this study was to investigate the effect of various experimental conditions on the adhesive strength of hard direct reline resins to denture base resin. The experimental conditions were as follows: 1) immersion time of denture base resin before relining, 2) amount of load at relining, 3) roughness of adhesive surface, 4) immersion time of relined resin. The following results were obtained: 1. The adhesive strength of Rebaron was the highest, followed by that of TRIAD and KOOLiner. 2. The immersion times of denture base resin did not appreciably affect the adhesive strength. 3. With the rougher adhesive surface, Rebaron and KOOLiner showed a tendency to increase adhesive strength. 4. The adhesive strength was not appreciably affected by load. 5. We did not find a definitive correlation between adhesive strength and immersion times of relined resin.

Adhesiveness↗
PubMed1989

Hypoparathyroidism during alpha-INF therapy in a patient with multiple myeloma.

A 66 year-old woman with multiple myeloma developed hypoparathyroidism during combination chemotherapy with melphalan, prednisolone, and alpha-interferon (INF). Seven weeks after commencement of the therapy, the serum calcium (Ca) level decreased to 7.4 mg/dL, and the phosphorus (P) level increased to 7.2 mg/dL; parathyroid hormone (PTH) was at a critically low level. By 13 weeks after discontinuation of alpha-INF, the levels of Ca, P, and PTH had returned to normal values: 8.6 mg/dL, 4.5 mg/dL, and 310 pg/ml, respectively. These changes suggest a strong correlation between hypoparathyroidism and the administration of alpha-INF. Autoantibodies against the parathyroid gland cell were not present in the serum of this patient by indirect immunofluorescent techniques. The mechanism of hypoparathyroidism by alpha-INF could not be identified, but this is the first case of this condition during alpha-INF therapy.

Aged↗
PubMed1989

Ectopic gastric mucosa of the gallbladder: comparison with metaplastic polyp of the gallbladder.

We report a case of ectopic gastric mucosa of the gallbladder in a 44-yr-old man. A sessile polypoid lesion 1.0 cm in diameter was seen in the body of the gallbladder, without gallstones. The polypoid lesion consisted of gastric pyloric glands and fundic glands. The surrounding mucosa consisted of ordinary gallbladder epithelium without any metaplastic change. To elucidate the characteristics of this lesion, a clinicopathological comparison was made with metaplastic polyp of the gallbladder.

Adult↗
PubMed1989

[Dimensional change and deformation on stone dies for full cast crowns. Differences according to impression methods using vinyl silicone impression materials].

In order to reconfirm the efficiency of an individual tooth tray, an apparatus and method were developed for measuring dimensional changes and observing over all deformation on a stone die for a full cast crown. The stone dies, which were made by combination impression methods I, II and double impression (individual tooth tray use) with vinyl silicone impression materials, were measured and compared. The results were as follows: 1. It made no difference what kind of vinyl silicone impression materials were used. 2. As to the dimensional changes: for combination impression method I, irregular results were found for the stone dies with the differences between +1 standard deviation (SD) and -1 SD being large. The variations of the other two methods were quite small, indicating that the stone dies were made accurately. 3. Observing to magnified images with the naked eye, there were no clear differences between the three methods on the marginal parts, but at the top corners of the stone dies there were good results with the double impression method. 4. It was possible to grasp easily the general aspect of dimensional changes in the stone dies using this newly developed measuring method.

Calcium Sulfate↗
PubMed1989

Correlation between the degree of deformation of the stone die and the amount of the master die undercut. Part 1. Single tooth die.

In order to investigate the deformation the stone die depending on the amount of undercut, 5 kinds of undercut master dies were used to take impressions using 3 kinds of impression materials (addition type silicone rubber, polysulfide rubber, alginate). The stone dies were measured for dimensional changes in shape as projected to a two-dimensional plane by means of a newly devised apparatus. The results showed that deformation of the stone dies increased, in general, in proportion to the amount of undercut of the master die. The stone dies obtained from addition type silicone rubber impression material tend to be less deformed. In the case of the polysulfide rubber impression, the deformation was very small in stone dies in the case of non-undercut master dies, but it was very large in the case of undercut master dies. The alginate impression materials gave results with wider variations.

Alginates↗
PubMed1989

[Adoptive immunotherapy by intra-arterial infusion of ATLAK or Allo-TLAK cells in patients with head and neck cancer].

For clinical application of adoptive immunotherapy, it is necessary to prepare a sufficient number of autologous tumor specific effector cells. A large amount of peripheral blood lymphocytes was obtained by leukapheresis using a Heamonetics V50 pheresis system. Autologous tumor- and lymphokine-activated killer (ATLAK) cells were induced by autologous mixed lymphocyte tumor cell culture (autologous MLTC) and further activation with recombinant interleukin-2 (rIL-2). Another problem was the difficulty of obtaining a sufficient number of highly activated effector cells to reach the target tumor tissue. Direct infusion of effector cells into a feeding artery was effective for cell accumulation in the target. ATLAK cells were infused into maxillary artery in 4 patients with maxillary squamous cell carcinoma. The results indicated that the therapy was effective for reduction of the tumor mass. After immunotherapy, surgery was performed and the tissues were histologically examined. Degenerated tumor cells and intensive infiltration by mononuclear cells and macrophages were seen in the surrounding fibrous tissue. However, the quantity of fresh autologous tumor cells available from open biopsy was limited. Allogeneic cultured tumor cell line was used as stimulator of lymphocytes instead of autologous tumor cells. The killing activity of the allogeneic tumor and lymphokine activated killer (Allo-TLAK) cells was significantly induced against the autologous tumor cells. Antitumor effect was observed in 5 out of 9 patients. Side effects were minor, such as slight fever and blood eosinophilia, which may be due to the rIL-2 function. These results indicate that this method of therapy is an effective form of adoptive immunotherapy.

Adult↗