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Biomedical subjects

Y Mikami

Publications and source records attributed to Y Mikami.

At least 235 records · Page 13Linked to original sources
PubMed1992

The postantifungal effect of 5-fluorocytosine on Candida albicans.

The in-vitro postantifungal effect (PAFE) of 5-fluorocytosine for Candida albicans for short periods of time was investigated. Yeast cells were exposed for 0.5, 1 or 2 h to a range of concentrations (0.1-3.2 mg/L) of 5-fluorocytosine. The PAFE was quantitated by determinations of the number of colony forming units at hourly intervals (0-10 h) after removal of the drug by dilution. The length of the PAFE was dependent upon the concentration of 5-fluorocytosine and the duration of exposure. An exposure time of 0.5 h resulted in PAFE's ranging from 0 to 4.2 h. Exposure times of 1 and 2 h resulted in longer PAFEs and in many instances suppression of cell growth was seen for the entire evaluation period (up to ten hours).

Candida albicans↗
PubMed1992

In-vitro activity of new carbapenem antibiotics: comparative studies with meropenem, L-627 and imipenem against pathogenic Nocardia spp.

MICs of two new carbapenems, meropenem and L-627, and imipenem were determined against 98 strains of the Nocardia asteroides group (i.e. N. asteroides sensu stricto, Nocardia farcinica and Nocardia nova), 46 strains of Nocardia brasiliensis and 17 strains of Nocardia otitidiscaviarum. Meropenem and L-627 were less active against the N. asteroides group than imipenem. Among the three species of the N. asteroides group, N. nova was the most sensitive to all the carbapenems. Meropenem was more active than imipenem against both N. brasiliensis and N. otitidiscaviarum with MIC50 values of 28.3-53.3 mg/L. L-627 was less active than meropenem.

Carbapenems↗
PubMed1992

Report of a study using phantom materials, and clinical experience with simultaneous radio-hyperthermotherapy.

Simultaneous radiohyperthermotherapy (SRH) is a combined hyperthermia-radiation therapy in which irradiation is given during heating. Mutual interference between the high energy radiotherapy system (Toshiba LMR-15A) and the 13.56 MHz capacitive heating system (Omron HEH-500C) was tested with phantom materials prior to a clinical trial with SRH. The energy and flatness of irradiation were not affected by the heating system within the range of clinical use. The high energy radiotherapy system did not affect the increase or distribution of temperature during simultaneous treatment. The results of this phantom study indicated that these apparatuses would not produce clinically significant mutual interference during SRH. A clinical trial was performed on a 57-year-old woman with postoperative recurrence of rectal cancer. This is the first reported clinical case treated with true SRH in which external irradiation was administered during mid capacitive heating. Twelve SRH treatments were performed on the recurrent lesion at a frequency of twice a week for six weeks using the apparatuses described above. There was a significant reduction in pain after treatment. The tumor marker carcinoembryonic antigen (CEA) level decreased after treatment. On CT images taken after treatment, the tumor site became a low density area which indicated necrosis. There were no side effects. These results suggest that further clinical study of SRH should be performed to clarify its advantages.

Body Temperature Regulation↗
PubMed1992

[Small cell carcinoma of the bladder. Small cell lung cancer-associated ganglioside (Fuc GM1) expression].

A 61-year-old male visited us with chief complaints of macroscopic hematuria and bladder irritation symptoms. Cystoscope, U/S, MRI, and CT showed an extensive non-papillary, wide-based tumor centering around the anterior wall of the bladder. Transabdominal U/S-guided full-thickness biopsy indicated a pT3a (Biopsy) primary small cell carcinoma of the bladder containing neuroendocrine granules. Immunohistochemical studies revealed Fuc GM1, an antigen related to small cell carcinoma of the lung. Neoadjuvant therapy consisted of preoperative irradiation at 50 Gy and intra-arterial infusion chemotherapy with CDDP and THP. Since a follow-up full thickness biopsy indicated pT0 (Biopsy), total cystectomy was performed. Examination of the resected specimen also indicated pathological CR.

Carcinoma, Small Cell↗
PubMed1992

The producer and biological activities of SO-75R1, a new mutactimycin group antibiotic [corrected].

The producer of SO-75R1, a new anthracycline group antibiotic was identified as Nocardia brasiliensis. SO-75R1 was active against Gram-positive bacteria, but not active against Gram-negative bacteria or fungi. All tested Nocardia brasiliensis strains as well as the producer itself were resistant to SO-75R1, although four other pathogenic Nocardia, i.e. N. asteroides, N. nova, N. farcinica and N. otitidiscaviarum were sensitive [corrected].

Animals↗
PubMed1991

Characterization of a neu/c-erbB-2 protein-specific activating factor.

The neu oncogene encodes a tyrosine kinase with growth factor receptor-like properties. A neu protein-specific activating factor (NAF) was partially purified from medium conditioned by the transformed human T-cell line ATL-2. NAF was able to stimulate the tyrosine-specific kinase activity of the neu protein (p185neu), induce dimerization and internalization, and increase the growth of cells bearing the neu protein. The effects of NAF were mediated by an interaction with the p185neu extracellular domain. NAF had no effect on the epidermal growth factor receptor kinase activity and no effect on cells that express that receptor. Further analysis of NAF and of other recently described neu protein-activating activities should help clarify the role of the neu protein in cell growth and transformation.

Cell Division↗
PubMed1991

Production of 5-methyluridine by immobilized thermostable purine nucleoside phosphorylase and pyrimidine nucleoside phosphorylase from Bacillus stearothermophilus JTS 859.

5-Methyluridine was produced continuously from thymine and inosine by immobilized enzymes, which consisted of thermostable purine nucleoside phosphorylase and thermostable pyrimidine nucleoside phosphorylase obtained from Bacillus stearothermophilus JTS 859. The process was carried out in a column reactor at 60 degrees C for 17 d without any bacterial contamination under non-aseptical conditions. Half-lives of the activity of the immobilized enzymes were 47 d and 4.5 d at 60 degrees C and 70 degrees C, respectively, although half-life of the crude enzyme was only 14 h at 70 degrees C.

Bacterial Proteins↗
PubMed1991

Bilateral open laminoplasty using ceramic laminas for cervical myelopathy.

Evaluation was done of 65 patients with cervical myelopathy treated by bilateral open laminoplasty using artificial laminas, between 1984 and 1988, who had been followed for more than 2 years. The mean recovery rate on the Japanese Orthopaedic Association scoring system was 65% in all cases, and 72% in the cases with no other complications. The artificial laminas appeared well adapted to the laminas in computed tomography and dynamic radiographic examinations, and there were no cases of reduction of the enlarged canal. Postoperative restriction of the range of motion of the cervical spine was lessened by the positioning of lateral grooves, more appropriate external fixation, and posterior flexion exercise after operation. This procedure is not technically complicated, it does not involve appreciable blood loss during operation, it prevents grafted free fat from migrating into the spinal canal, and is advantageous for posterolateral bone chip grafting.

Ceramics↗
PubMed1991

Inactivation of kanamycin A by phosphorylation in pathogenic Nocardia.

Among the five species of pathogenic Nocardia, i.e., N. asteroides, N. brasiliensis, N. farcinica, N. nova and N. otitidiscaviarum, all strains of N. brasiliensis and N. farcinica showed resistance to an aminoglycoside antibiotic, kanamycin A, showing the MIC (minimum inhibitory concentration) values of more than 100 micrograms/ml. This species-specific difference in sensitivity was found to be explained by the production of an inactivation enzyme, aminoglycoside 3'-phosphotransferase APH(3'). Structural studies by mass and NMR spectroscopy on the inactivated substance produced by a cell-free extract of the Nocardia confirmed the conversion of kanamycin A to an inactive substance, kanamycin A 3'-phosphate. The MIC values of N. otitidiscaviarum and N. nova for kanamycin A, on the other hand, ranged from 0.78 micrograms/ml to 100 micrograms/ml, and both species were non-producers of APH(3'). Sensitivity to the antibiotic and APH(3') productivity of N. asteroides varied depending on the strain.

Carbohydrate Sequence↗
PubMed1991

[Total body hyperthermia and continuous hyperthermic peritoneal perfusion as an adjuvant therapy in advanced gastric cancer].

Between September 1986 and July 1989, adjuvant hyperthermic therapy, consisting of either total body hyperthermia (TBHT) or continuous hyperthermic peritoneal perfusion (CHPP), was given to a total of 41 patients immediately following gastric resection for cancer. TBHT was performed in 1 curative- and 11 noncurative-gastrectomized patients (1 stage III and 11 stage IV), and CHPP in 18 curative- and 11 noncurative-gastrectomized patients (6 stage I/II, 10 stage III and 13 stage IV). For TBHT, the blood was warmed and maintained at 42 degrees C for 3 hours by means of a V-V bypass connected to an extracorporeal heater-pumping system. When the hyperthermic condition was established, anti-cancer drugs were administered intravenously. In CHPP, 46 degrees C saline containing anti-cancer drugs were infused at a constant rate through a tube placed at the Douglas fossa. The perfusate was drained out through another tube positioned at an uppermost part of the abdominal cavity. The hyperthermic condition was monitored by measuring the outflow temperature. Complications encountered were bone marrow depression, liver damage and pyrexia, and were more frequently experienced by the TBHT patients. Patients under 65 years of age who had had an absolute noncurative gastrectomy but with TBHT survived significantly longer than those without TBHT. When the patients who had undergone gastrectomy with CHPP for a cancer of more than se penetration were compared with those without CHPP, there was no significant difference in survival found between these two populations. This unsatisfactory result could be partly attributable to difficult maintenance of appropriate (sufficiently high) and constant perfusate temperature.

Adult↗
PubMed1991

[Continuous hyperthermic peritoneal perfusion (CHPP) therapy in advanced gastric cancer].

In CHPP therapy for advanced gastric cancer, a perfusate containing 20 mg CDDP and 8 mg MMC in 1,000 ml physiologic saline warmed at 47 degrees C was infused at a constant rate of 200 ml/min into the pouch of Douglas. The intraperitoneal temperature at the supra-pancreatic region was around 39.0 degrees C. To obtain a more stable and higher intraperitoneal temperature, the infusing rate was increased to 400 ml/min. This yielded a 3 degrees C higher temperature (42 degrees C) at the same measuring site. However, the temperature recorded at various intraperitoneal sites did not always reach such an effective range. The maximal plasma concentrations of MMC determined during CHPP at the 200 and 400 ml/min infusion were 0.09 +/- 0.03 and 0.11 +/- 0.03 microgram/ml, and those of CDDP 1.6 +/- 0.4 and 1.7 +/- 0.3 microgram/ml, respectively, all of which were not significantly different. When an intraperitoneal dosage of 20 mg MMC was given to 3 patients, the portal venous blood, at 10 min after the administration, produced a 1.7 times higher concentration of the agent than did the peripheral venous blood. This discrepancy between the two concentrations was much smaller than found by other investigators in animal experiments.

Adult↗
PubMed1991

[Measurement of anti-microsomal and anti-thyroglobulin antibodies by radioimmunoassay].

In this study, we measured anti-microsomal (same as anti-thyroid peroxidase) and anti-thyroglobulin antibodies (anti-TPOAb and anti-TgAb) in sera by new RIA kits and compared with the conventional particle agglutination (PA) kits. Two of 80 normals (2.5%) showed anti-TPOAb positive activity (greater than or equal to 0.3 unit/ml), and 9 of same samples (11.3%) showed anti TgAb positive activity (greater than or equal to 0.3 unit/ml). Sixty of 67 patients with Graves' disease (89.6%), and 14 of 22 with Hashimoto's disease (63.6%) were anti-TPOAb positive, and 42 (62.7%), and 18 (81.8%) were anti-TgAb positive respectively. Samples of 5 non-autoimmune disease were all negative by TPOAb and TgAb assays, suggesting the high specificity of new RIA kits to the autoimmune thyroid diseases. The RIA and PA methods showed a good correlation (anti-TPOAb:rs = 0.9134, anti-TgAb:rs = 0.7016). However, several negative sera in PA assay showed positive values in the RIA, so it was showed that new RIA kits were more sensitive than the PA assays.

Autoantibodies↗
PubMed1990

A toxic substance produced by Nocardia otitidiscaviarum isolated from cutaneous nocardiosis.

During our studies on toxic substances from clinically isolated Nocarida, a new isolate identified as Nocardia otitidiscaviarum from cutaneous nocardiosis was found to produce a toxic substance called HS-6 that had strong in vitro as well as in vivo toxicity. The mouse intraperitoneal LD50 value was 1.25 mg/kg and the ED50 value for L1210 cultured cells was 0.3 ng/ml. The structure of HS-6 was determined and found to belong to the 16-membered macrocyclic group with a molecular formula of C43H68O12. HS-6 also showed activity against pathogenic fungi such as Cryptococcus neoformans.

Aged↗
PubMed1990

Effects of carvedilol on serum lipids in hypertensive and normotensive subjects.

The effects of carvedilol (an alpha.beta-blocker) on lipid metabolism were assessed in addition to its hypotensive effect. The subjects were 18 men and 18 women, 20 with hypertension and 16 normotensives with other conditions requiring carvedilol treatment. They were aged from 31 to 79 years and were given a daily dose of 5-20 mg carvedilol (average, 9.7 mg/day) for 12 weeks. Significant falls were seen in blood pressure and heart rate after 12 weeks in the hypertensive subjects (mean +/- SE) (systolic: from 164 +/- 2 to 141 +/- 2 mm Hg, P less than 0.001; diastolic: from 98 +/- 1 to 85 +/- 2 mm Hg, P less than 0.001; heart rate: from 71 to 65 beats/min, P less than 0.001). Smaller changes in blood pressure and heart rate were seen in the normotensive subjects, with the fall in systolic pressure being significant (from 143 +/- 3 to 135 +/- 2 mm Hg, P less than 0.01). There were no significant changes in the overall serum total cholesterol, triglycerides, high-density lipoprotein (HDL) cholesterol, and phospholipid levels. In the subgroup with a pretreatment serum triglyceride level of greater than 150 mg/dl, a significant fall of 52.1 mg/dl was seen (P less than 0.05). Lipoprotein analysis showed a significant fall in alpha-lipoprotein levels (P less than 0.05). The atherogenic index did not change significantly, and it was concluded that carvedilol was an effective antihypertensive agent that produced no adverse effects and possibly had beneficial effects on lipid metabolism.

Adrenergic beta-Antagonists↗
PubMed1990

Comparison of atrophic and goitrous auto-immune thyroiditis in children: clinical, laboratory and TSH-receptor antibody studies.

We studied the clinical features, laboratory and thyroid functions and thyrotropin (TSH)-receptor and thyroid-stimulation antibodies in 21 patients with atrophic auto-immune thyroiditis (AAT) and 48 patients with goitrous auto-immune thyroiditis (GAT) of childhood onset. The clinical features of patient with AAT were cessation of growth and obesity, while asymptomatic enlargement of the thyroid gland was the sole symptom in most patients with GAT. Although the ages at diagnosis were comparable in both groups, the estimated ages at onset were much lower in patients with AAT than in those with GAT. Patients with AAT exhibited more severe hypothyroidism when evaluated by serum thyroxine (T4), tri-iodothyronine (T3), TSH, cholesterol levels and basal metabolic rates. The 24 h 123I-thyroidal uptake was significantly lower in patients with AAT than in those with GAT. None of the 19 patients with AAT possessed TSH-binding inhibitor immunoglobulins (TBII). On the other hand, 3 of the 32 GAT patients tested, possessed weak to potent TBII activities. Three TBII-positive patients with GAT also possessed thyroid-stimulation blocking antibodies. These findings suggest that: 1. Pathogenesis of AAT in children whose onset of hypothyroidism was before puberty is not due to TSH-receptor blocking antibodies, which are often found in patients with AAT of postpubertal onset. 2. AAT in children is considered not to be due to the later stage of GAT. 3. Some patients with GAT possessed TSH-receptor blocking antibodies. The aetiology and pathogenesis of AAT in children have yet to be elucidated.

Adult↗