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Biomedical subjects

K Miyauchi

Publications and source records attributed to K Miyauchi.

At least 55 records · Page 3Linked to original sources
PubMed1997

Successful treatment of an esophageal hemangioma by endoscopic injection sclerotherapy: report of a case.

We report herein the case of a 46-year-old man in whom an esophageal hemangioma was successfully treated by endoscopic injection sclerotherapy (EIS). The patient was admitted to hospital after a routine upper gastrointestinal series demonstrated a filling defect in the esophagus. Endoscopy, computed tomography (CT) images, and magnetic resonance imaging (MRI) subsequently revealed a hemangioma in the middle esophagus. EIS was performed using 99% ethanol and 1% polydocanol, and 4 weeks later, the tumor had almost disappeared. This patient has since been followed up carefully with periodic endoscopy and barium studies and additional sclerotherapy will be performed if necessary.

Esophageal Neoplasms↗
PubMed1997

Purification and characterization of a haloalkane dehalogenase of a new substrate class from a gamma-hexachlorocyclohexane-degrading bacterium, Sphingomonas paucimobilis UT26.

The linB gene product (LinB), 1,3,4,6-tetrachloro-1,4-cyclohexadiene halidohydrolase, which is involved in the degradation of gamma-hexachlorocyclohexane in Sphingomonas paucimobilis UT26 (Y. Nagata, T. Nariya, R. Ohtomo, M. Fukuda, K. Yano, and M. Takagi, J. Bacteriol. 175:6403-6410, 1993), was overproduced in E. coli and purified to homogeneity. The molecular mass of LinB was deduced to be 30 kDa by gel filtration chromatography and 32 kDa by electrophoresis on sodium dodecyl sulfate-polyacrylamide gel, indicating that LiuB is a monomeric enzyme. The optimal pH for activity was 8.2. Not only monochloroalkanes (C3 to C10) but also dichloroalkanes, bromoalkanes, and chlorinated allphatic alcohols were good substrates for LinB, suggesting that LinB shares properties with another haloalkane dehalogenase, DhlA (S. Keuning, D.B. Janssen, and B. Witholt, J. Bacteriol. 163:635-639, 1985), which shows significant similarity to LinB in primary structure (D. B. Janssen, F. Pries, J. van der Ploeg, B. Kazemier, P. Terpstra, and B. Witholt, J. Bacteriol. 171:6791-6799, 1989) but not in substrate specificity. Principal component analysis of substrate activities of various haloalkane dehalogenases suggested that LinB probably constitutes a new substrate specificity class within this group of enzymes.

Biodegradation, Environmental↗
PubMed1997

[A comparative study between low-dose and high-dose medroxyprogesterone acetate (MPA) in the treatment of advanced and recurrent breast cancer--in relation to dose, serum concentration and response. Osaka Breast Cancer Research Group].

A prospective randomized study was carried out to evaluate the effectiveness of MPA in the treatment of breast cancer by comparing low dose (600 mg/day) with high dose (1,200 mg/day) of MPA. In 35 evaluable cases, the response rate to treatment was 40.0% (8/20) with low dose MPA and 26.7% (4/15) with high dose MPA. There was no significant difference between the two groups. The serum MPA concentration measured by high-performance liquid chromatography (HPLC) assay was 23.2 +/- 17.6 ng/ml in the low-dose group and 89.5 +/- 56.7 ng/ml in the high-dose group. Intrapatient variability in serum MPA concentration was relatively stable, but interpatient variability was large. No correlation was found between the response rate and serum MPA concentration. The above results indicate that a low dose of MPA (600 mg/day) is a useful treatment with high effectiveness and safety in advanced and recurrent breast cancer patients. Though no exact data on the optimal serum concentration could not be obtained, it was obvious that a successful response cannot be expected from a serum MPA concentration of less than 17 ng/ml, which was the average serum concentration in NC and PD patients of the low-dose group.

Adult↗
PubMed1997

[Percutaneous transluminal coronary angioplasty in patients with multivessel coronary disease: does complete revascularization improve the long-term survival?].

The influence of complete revascularization on long-term outcome of patients with multivessel coronary artery disease undergoing percutaneous transluminal coronary angioplasty (PTCA) was determined by analysis of 10-year survival in 167 consecutive patients treated at Juntendo University Hospital during 1984-1993. Forty-nine patients were completely revascularized and 118 had incomplete revascularization according to the anatomical classification. Among patients with anatomically incomplete revascularization, 56 were categorized as functionally adequate revascularization and 62 as functionally inadequate revascularization according to Faxon's criteria. Baseline characteristics showed incompletely revascularized patients had a higher incidence of prior myocardial infarction triple-vessel disease and/or chronic total occlusion in at least one lesion. The 10-year survival was slightly better in patients with complete (100%) than in those with incomplete revascularization (79%), but not statistically significant (p = 0.089). Event-free survival was not significantly different between the two groups. However, the need for coronary artery bypass surgery was higher in the incomplete revascularization group than that in the complete revascularization group (100% vs 81%, p = 0.013). The influence of the degree of functional revascularization on outcome was not clear in the present study. Long-term survival appeared to be better in patients with complete revascularization than that in patients with incomplete revascularization, but even in the latter, coronary artery bypass grafting in the later period could improve outcome. The effect of functional revascularization status should be further investigated in a larger population.

Angioplasty, Balloon, Coronary↗
PubMed1997

[Hemodynamic analysis of pulsatile blood flow in arteries by MRI].

The purpose of this study was to analyze the hemodynamics of pulsatile blood flow in arteries by MRI. The blood flow velocity was calculated by dividing the traveled distance of blood bolus by the echo time obtained from DBI images. Pulsatile water flow in the phantom and blood flow in abdominal aorta of 27 volunteers were estimated by means of both the DBI image and an approximate equation of flow velocity. The measured flow well agreed with the actual flow in the flow phantom study. Three-dimensional flow velocity profiles calculated using the approximate equation were similar to the DBI images and had the characteristics of pulsatile flow. The negative flow velocity near the aortic wall could be expressed in the flow velocity profiles by the approximate equation. The maximum flow velocities at the center of the abdominal aorta and the time-averaged wall shear stress calculated by the approximate equation decreased with aging (r = -0.78 P < 0.0001 and r = -0.64 P < 0.0003, respectively). The present results suggest that the DBI method and analysis based on the approximate equation proposed here will be valuable to analyze the hemodynamics of pulsatile blood flow.

Adult↗
PubMed1996

Acute radiation thyroiditis.

PURPOSE: Radiation-induced thyroid dysfunction is considered a late effect. We prospectively assessed acute reactions of the thyroid to external neck irradiation. METHODS AND MATERIALS: This study included 22 patients in whom the thyroid was incidentally exposed to therapeutic doses of radiation. Thyroid function tests included measurements of serum thyroid stimulating hormone (TSH), free and total triiodothyronine (T3) and thyroxine (T4), thyroglobulin, and antithyroid antibodies. These tests were performed before radiotherapy (baseline values), after approximately 40 Gy had been administrated, 2 weeks after the end of radiotherapy, and 3 and 6 months after the beginning of radiotherapy. RESULTS: Mean serum levels of TSH were 1.53, 0.55, 0.78, 2.14, and 7.57 microU/ml before radiotherapy, after 40 Gy irradiation, 2 weeks after the end of radiotherapy, and 3 and 6 months after radiotherapy, respectively. Thus, levels of TSH exhibited two phases: a significant decrease during radiotherapy (thyrotoxic phase) and an increase after radiotherapy (hypothyroid phase) (baseline vs. 40 Gy: p < 0.0001, baseline vs. 6 months: p = 0.003). Increases of thyroid hormones were subtle during radiotherapy. CONCLUSIONS: We believe that radiation promotes release of excessive amounts of thyroid hormones during radiotherapy owing to suppression of TSH secretion. In addition to the late damage (hypothyroidism), thyrotoxicosis occurs when the thyroid gland receives a therapeutic doses of external radiation.

Acute Disease↗
PubMed1996

The effect of combination splenectomy and low-dose FK506 therapy on graft survival after liver allograft transplantation in rats.

The effect of splenectomy on allograft survival was investigated using orthotopic liver transplantation in a rat experimental model (ACI rat liver grafted to LEW rat). Control rats without any immunosuppressive treatment died, on average, 10.4 +/- 1.4 days after operation. Splenectomy alone somewhat prolonged the survival (13.4 +/- 2.0 days), and low-dose FK506 therapy moderately prolonged it (22.7 +/- 7 days). The graft survival period was significantly prolonged (39.7 +/- 6.3 days) when them two treatments were combined. The elevation of cytotoxic antiallograft antibodies was suppressed by splenectomy but not by low-dose FK506 therapy. The development of jaundice was moderately suppressed by FK506 but not by splenectomy. There was no difference between the pattern of body weight decline in either of them two groups and that in control rats. When these two treatments were combined at the same time, the elevation of cytotoxic antibodies, development of jaundice and decline of body weight were suppressed. These data indicate that B cells play an important role in the acute rejection of the rat liver allograft at least partially via production of cytotoxic antiallograft antibody. Splenectomy or other immunosuppressive methods affecting B cells can be a supplement for immunosuppression when using reduced-dose FK506.

Animals↗
PubMed1996

A prospective analysis of subacute thyroid dysfunction after neck irradiation.

PURPOSE: Exposure of the thyroid to therapeutic doses of external irradiation has been demonstrated to induce thyroid dysfunction. This study was designed to assess the relationship between irradiation and early thyroid dysfunction, prospectively. METHODS AND MATERIALS: Twenty patients in whom the thyroid was incidentally exposed to therapeutic doses of irradiation were studied. The dose given to the thyroid was 40-54 Gy over 4-7 weeks. Thyroid function tests, including serum thyroid stimulating hormone (TSH), free thyroxine (free T4), free triiodothyronine (free T3), antithyroglobulin antibody, and antimicrosomal antibody, were performed prior to irradiation and at 3, 6, and 12 months after radiotherapy. RESULTS: Serum TSH levels did not change significantly at 3 months after irradiation (mean TSH level: 1.33 microU/ml before irradiation, 1.74 microU/ml at 3 months, p = 0.11). However, a significant elevation was noted at 6 months (mean TSH: 3.50 microU/ml at 6 months, p = 0.0001, vs. preirradiation), when TSH levels were higher than preirradiation levels in 19 of 20 patients. After irradiation, 13 patients remained in a euthyroid state (euthyroid group), while in the other 7 patients hypothyroidism occurred (hypothyroid group) and thyroid hormone-replacement therapy was performed. After 6 months, elevation of TSH was less significant in the euthyroid group, whereas elevation of TSH persisted continuously and exponentially in the hypothyroid group. Thyroid autoantibodies did not turn positive in any patient during follow-up. CONCLUSIONS: Damage of the thyroid develops in most patients when the organ is exposed to radiation. This radiation-induced damage is initially manifested within 6 months after irradiation.

Adult↗
PubMed1996

Therapeutic efficacy of an antineutrophil monoclonal antibody, Urge-8, against acute necrotizing pancreatitis in rats.

BACKGROUND: Although they have critical roles in the defense mechanism against invading microorganisms, neutrophils may facilitate exacerbation of critical conditions associated with acute necrotizing pancreatitis by a discharge of granule contents into the organ tissues. Because of this constitution of neutrophils, the therapeutic efficacy of Urge-8, a mouse monoclonal antibody to neutrophils, on the survival of rats with experimentally induced acute necrotizing pancreatitis was investigated in vivo. METHODS: Acute pancreatitis was induced by injection of trypsin mixed with sodium chenodeoxycholic acid into pancreatic ducts. Urge-8 was infused intravenously 30 minutes after pancreatitis was induced, a series of vital signs was taken, and plasma amylase level was estimated. RESULTS: Hemorrhagic necrosis of the pancreas and intraabdominal bleeding were observed 1 hour after the pancreatitis-inducing drugs were injected, and death occurred at 240.9 +/- 24.6 minutes (mean +/- SD)in the control group. With Urge-8 administration, however, the survival time was significantly prolonged to 395.2 +/- 64.4 minutes (p = 6.0 x 10-(10) versus control). Failure in the vital signs (mean arterial pressure, heart rate, and body temperature) was significantly ameliorated by injection of Urge-8. The plasma amylase level was elevated after pancreatitis was induced and peaked at 3 hours (4915 +/- 1966 IU/L in mean +/- SD). This level was suppressed during the first 3 hours by injection of Urge-8 (3372 +/- 1223 IU/L); however, the amylase level increased thereafter, becoming comparable with the peak in the control group, and then death occurred. Arterial blood gas and plasma electrolyte analyses showed that pH, base excess, and plasma potassium levels in the group treated with monoclonal antibody were significantly improved. CONCLUSIONS: It was suggested that neutrophils play some critical role in the exacerbation of acute necrotizing pancreatitis and its related symptoms. Although not capable of preventing death in our model, treatment with the antineutrophil monoclonal antibody Urge-8 after the onset of acute pancreatitis prolonged the survival time significantly.

Acute Disease↗
PubMed1996

Prolongation of rat liver graft survival by splenectomy combined with low dose FK506 therapy.

The effects of low dose FK506 therapy (0.1 mg/ kg/day x 1 day) on graft survivals were analyzed, and the feasibility of splenectomy was assessed. ACI strain liver grafts were orthotopically implanted into LEW male rat recipients. In the control group, the survival period was 10.4 +/- 1.4 days. In the group treated with splenectomy, the survival period was 13.4 +/- 2.0 days. In the groups with low dose FK506 therapy, the survival periods were 22.7 +/- 6.7 and 39.7 +/- 6.3 days with or without splenectomy, respectively. Rats in the group with average dose FK506 (1.0 mg/kg/day x 7 days) survived more than 100 days. In summary, the effect of low dose FK506 therapy was relatively limited. Splenectomy by itself was marginally effective; however, this effect was enhanced when combined with low dose FK506 therapy.

Animals↗
PubMed1996

Antibacterial activity of xanthones from guttiferaeous plants against methicillin-resistant Staphylococcus aureus.

Extracts of Garcinia mangostana (Guttiferae) showing inhibitory effects against the growth of S. aureus NIHJ 209p were fractionated according to guidance obtained from bioassay and some of the components with activity against methicillin-resistant Staphylococcus aureus (MRSA) were characterized. One active isolate, alpha-mangostin, a xanthone derivative, had a minimum inhibitory concentration (MIC) of 1.57-12.5 micrograms mL-1. Other related xanthones were also examined to determine their anti-MRSA activity. Rubraxanthone, which was isolated from Garcinia dioica and has a structure similar to that of alpha-mangostin, had the highest activity against staphylococcal strains (MIC = 0.31-1.25 micrograms mL-1), an activity which was greater than that of the antibiotic vancomycin (3.13-6.25 micrograms mL-1). The inhibitory effect against strains of MRSA of two of the compounds when used in conjunction with other antibiotics was also studied. The anti-MRSA activity of alpha-mangostin was clearly increased by the presence of vancomycin; this behaviour was not observed for rubraxanthone. The strong in-vitro antibacterial activity of xanthone derivatives against both methicillin-resistant and methicillin-sensitive Staphylococcus aureus suggests the compounds might find wide pharmaceutical use.

Anti-Bacterial Agents↗
PubMed1996

Antibacterial activity of some Garcinia benzophenone derivatives against methicillin-resistant Staphylococcus aureus.

Benzophenone derivatives, garcinol (1) and isogarcinol (2) isolated from the pericarps of Garcinia purpurea (Guttiferae), and xanthochymol (3) and a mixture of isoxanthochymol (4) cycloxanthochymol (5) from the pericarps of G. subelliptica were evaluated for their antibacterial activity against methicillin-resistant Staphylococcus aureus. Among them, 3 showed the lowest minimum inhibitory concentration at 3.1-12.5 micrograms/ml. This concentration is nearly equal to that of the antibiotic, vancomycin.

Anti-Bacterial Agents↗
PubMed1995

Direct measurement of high-density lipoprotein cholesterol in serum with polyethylene glycol-modified enzymes and sulfated alpha-cyclodextrin.

We have developed an automated method for measuring high-density lipoprotein (HDL)-cholesterol in serum without prior separation, using polyethylene glycol (PEG)-modified enzymes and sulfated alpha-cyclodextrin. When cholesterol esterase and cholesterol oxidase enzymes were modified with PEG, they showed selective catalytic activities towards lipoprotein fractions, with the reactivity increasing in the order: low-density lipoprotein < very-low-density lipoprotein approximately chylomicron < HDL. In the presence of magnesium ions, alpha-cyclodextrin sulfate reduced the reactivity of cholesterol, especially in chylomicrons and very-low-density lipoprotein, without the need for precipitation of those lipoprotein fractions. The combination of PEG-modified enzymes with alpha-cyclodextrin sulfate provided selectivity for the determination of HDL-cholesterol in serum in the presence of a small amount of dextran sulfate without the need for precipitation of lipoprotein aggregates. The results of the HDL-cholesterol assayed in serum by this direct method correlated well with those obtained by precipitation-based methods and also that by an ultracentrifugation method.

Adult↗
PubMed1994

Cloning and sequencing of a 2,5-dichloro-2,5-cyclohexadiene-1,4-diol dehydrogenase gene involved in the degradation of gamma-hexachlorocyclohexane in Pseudomonas paucimobilis.

In Pseudomonas paucimobilis UT26, gamma-hexachlorocyclohexane (gamma-HCH) is converted to 2,5-dichloro-2,5-cyclohexadiene-1,4-diol (2,5-DDOL), which is then metabolized to 2,5-dichlorohydroquinone. Here, we isolated from the genomic library of UT26 two genes which expressed 2,5-DDOL dehydrogenase activity when they were transformed into P. putida and Escherichia coli. Both gene products had an apparent molecular size of 28 kDa by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The first gene, named linC, located separately from the two genes (linA and linB) which we had already cloned as genes involved in the gamma-HCH degradation. The other, named linX, located about 1 kb upstream of the linA gene encoding gamma-HCH dehydrochlorinase. A gamma-HCH degradation-negative mutant, named UT72, which lacked the whole linC gene but had the intact linX gene was isolated. The linC gene given in a plasmid could complement UT72. These results strongly suggest that the linC gene but not the linX gene is essential for the assimilation of gamma-HCH in UT26. Deduced amino acid sequences of LinC and LinX show homology to those of members of the short-chain alcohol dehydrogenase family.

Alcohol Oxidoreductases↗
PubMed1993

Distribution of fluoride in cortical bone of human rib.

We describe a detailed study of fluoride distribution with age in the human cortical rib bone. Human ribs were obtained from 110 subjects (M:68, F;42) aged 20-93 years. The fluoride distribution from the periosteal to endosteal surfaces of the ribs was determined by sampling each specimen using an abrasive micro-sampling technique, and the samples were analyzed using the fluoride electrode, as described by Weatherell et al. [1]. The concentration of fluoride was highest in the periosteal region, decreased gradually towards the interior of the tissue where the concentration of fluoride tended toward the plateau, and then rose again towards the endosteal surface. Patterns of fluoride distribution changed with age, and the difference between periosteal and endosteal fluoride levels increased with age. Although average fluoride concentrations increased with age in both sexes, there was a significant difference between males and females at the age of about 55 years (P < 0.05).

Adult↗