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F Nagao

Publications and source records attributed to F Nagao.

At least 19 recordsLinked to original sources
PubMed2001

Highly sensitive determination of plasma cytokines by time-resolved fluoroimmunoassay; effect of bicycle exercise on plasma level of interleukin-1 alpha (IL-1 alpha), tumor necrosis factor alpha (TNF alpha), and interferon gamma (IFN gamma).

A highly sensitive time-resolved fluoroimmunoassay of human plasma cytokines is described. The cytokines such as interleukin-1 alpha (IL-1 alpha), tumor necrosis factor alpha (TNF alpha) are known to be acute inflammatory cytokines and it has been reported that these cytokines are secreted into blood by physical exercise. In this study, a sandwich-type immunoassay of cytokines was established using a europium chelate BHHCT-Eu3+ as a powerful labeling material. The minimum detection limits of cytokines, i.e. IL-1 alpha, TNF alpha, and interferon gamma (IFN gamma) were about 1/10 smaller than those of enzyme-linked immunosorbent assay currently used. By this immunoassay we investigated cytokine increase/decrease in plasma which was thought to derive from the myocytes damaged by bicycle exercise. Healthy young men performed two kinds of bicycle ergometer exercises, under conditions of an incremental and a constant loading. Blood samples were taken before, during, and after exercises, and the concentration levels of plasma IL-1 alpha, TNF alpha, and IFN gamma were determined. In the case of incremental exercise, IL-1 alpha increased significantly at the first stage but decreased to the basal level from the second stage, in spite of heavier exercise. In the case of 30 min constant exercise, the level of plasma IFN gamma increased in recovery period, 2 h after the light-exercise. TNF alpha level was significantly higher in a heavy-exercise. The concentration of IL-1 alpha peaked at the early stage of the incremental exercise; this fact has not been reported in previous studies. This cytokine is unique in showing a sudden increase during the early stage, while others increase after the exercise. Our highly sensitive assay made it possible to detect a slight change in plasma cytokines.

Adult↗
PubMed2000

Detection and measurement of a single blood cell surface antigen by thermal lens microscopy.

A highly sensitive method for detection of antigens on the surface of a single blood cell using thermal lens microscopy is described. Colloidal gold, coated with antibody, was used to stain membrane antigens of leukocytes. Human leukocyte antigens on the lymphocytes and mononuclear leukocytes were observed by new thermal lens microscopy, which involves spectrometry using a laser-induced thermal-lens effect. Antigens of HLA-A, -B, and -C loci on the lymphocytes were identified and quantitated using a single cell. The image of HLA-A, -B, and -C antigen distribution on a mononuclear leukocyte was obtained. Our laser microscope, newly devised for measuring convex surface cells, is a powerful analytical tool for detecting and quantitating localized antigens in a single cell and/or cell-surface-associated molecules.

Antigens↗
PubMed2000

Mobilization of NK cells by exercise: downmodulation of adhesion molecules on NK cells by catecholamines.

The change of plasma catecholamine concentration correlates with the change of natural killer (NK) activity and NK cell number in peripheral blood mononuclear cells (PBMC) during and after moderate exercise. We studied the causal relation between exercise-induced catecholamine and expression of adhesion molecules on NK cells during and after exercise. The expression of CD44 and CD18 on CD3(-)CD56(+) NK cells was significantly reduced during exercise (P < 0.01). When PBMC were stimulated with 10(-8)M norepinephrine in vitro, the expression of these adhesion molecules on CD3(-)CD56(+) NK cells was downmodulated within 30 min. The binding capacity of NK cells to a CD44 ligand, hyaluronate, was reduced by the stimulation with norepinephrine (P < 0.01). The intravenous injection of norepinephrine in mice decreased the expression of CD44 and CD18 on CD3(-)NK1.1(+) cells (P < 0.01) and increased the number of CD3(-)NK1.1(+) cells in PBMC (P < 0.01). These findings suggest that exercise-induced catecholamines modulate the expression of adhesion molecules on NK cells, resulting in the mobilization of NK cells into the circulation.

Adult↗
PubMed2000

Effects of a fermented milk drink containing Lactobacillus casei strain Shirota on the immune system in healthy human subjects.

Nine healthy volunteers drank fermented milk containing 4 x 10(10) live cells of Lactobacillus casei strain Shirota daily for 3 weeks, and their NK activity and other immunological functions were measured. NK activity significantly increased (p<0.01) 3 weeks after the start of intake and remained elevated for the next 3 weeks. The effect was particularly prominent in low-NK-individuals.

Adult↗
PubMed1998

[NK cell activity and subsets of truck drivers along with related factors].

We investigated the immunity and the main factors that affect the immune system of 19 truck drivers as the experimental group and 27 office workers as the control group at a transit corporation in Tokyo; all subjects in both groups were examined through an assay of NK activity and NK subsets before and after work. At the same time, they were asked to complete a questionnaire on their working hours per day (WHPD) and driving hours per day (DHPD), in addition to the Health Practice Index (HPI), Self-Rating Depression Scale (SDS), Stress Tolerance Check List (STCL), and Symptom Checklist (SCL). The results obtained were as follows: 1. Before work, no difference was seen in NK activity between the experimental group and the control group, with both groups showing E:T ratios 5:1 to 20:1. After work, the NK activity (E:T = 20:1) of the experimental group was significantly lower than that of the control group. 2. In the experimental group, the NK activity and NK subsets (CD3-CD16+CD56+, CD3-CD56+, CD3-CD16+) of the peripheral blood lymphocytes after work were significantly lower than before work (p < 0.05, p < 0.01, p < 0.01). After more than five driving hours, the value of the CD3-CD16+CD56+ subset was significantly lower than that after fewer driving hours. 3. Correlation coefficients were calculated based on the average value of NK activity (E:T = 20:1), CD3-CD16+CD56+ subset, and WHPD, DHPD, and HPI in the driving group. NK activity (E:T = 20:1) and DHPD were found to be negatively correlated (r = -0.28), as were the CD3-CD16+CD56+ subset and WHPD (r = -0.43) and the CD3-CD16+CD56+ subset and DHPD (r = -0.63). On the other hand, NK activity (E:T = 20:1), the CD3-CD16+CD56+ subset and HPI were found to be positively correlated (r = 0.41 and 0.33).

Adult↗
PubMed1997

Polymorphism of murine Fas ligand that affects the biological activity.

Fas ligand (FasL) is a member of the tumor necrosis factor family and induces apoptosis in Fas (CD95)-bearing target cells. In this study, we generated several mAbs that react with mouse FasL (mFasL) and characterized their functional properties. One of these mAbs, K10, specifically reacted with mFasL derived from C57BL/6 (B6) mice, but not that from BALB/c mice as estimated by surface staining and blocking of cytotoxic activities of mFasL transfectants, suggesting a polymorphism of mFasL. Sequence analysis of mFasL cDNA from several strains revealed that BALB/c and DBA/2 mice have three nucleotide differences from the known B6 and C3H sequences, which result in two amino acid substitutions (Thr-184 --> Ala-184 and Glu-218 --> Gly-218) in the extracellular region. Analysis of the K10 reactivity and genotyping by PCR-restriction fragment length polymorphism revealed that inbred mice segregate into the following two allotypes: mFasL.1 (B6, C3H, MRL, SJL, NOD, NZB, NZW) and mFasL.2 (BALB/c, DBA/1, DBA/2). Interestingly, COS7 cells expressing BALB/c FasL lysed Fas-bearing target cells more efficiently than those expressing B6 FasL. Furthermore, BALB/c-derived CD8-FasL fusion protein, which is composed of the extracellular domains of human CD8alpha and mFasL, exhibited 9-fold higher specific activity than did B6-derived CD8-FasL. These results suggest that in mFasL.2 mice the Fas/FasL system works more effectively than in mFasL.1 mice.

Alleles↗
PubMed1997

Japanese population does not manifest significant association between low NK activity and HLA-B(C) locus homozygosity.

It was reported previously that natural killer (NK) activity is controlled by the HLA-B(C) region and that individuals homozygous for HLA-B(C) or homozygous for the NKB complementation groups, which are mapped to the HLA-B(C) region, have fewer circulating NK cells and lower NK activity than do individuals heterozygous for these alleles. Those studies had used subjects in the United States. In the present study, we investigated the NK activity, NK subpopulation, and HLA types of 65 healthy Japanese individuals in Japan, most of whom have a quite different HLA-B(C) type than did subjects in the earlier study. Among 13 individuals having low NK activity, only two were HLA-B(C) homozygous and the rest were heterozygous. No obvious relation between low NK activity and specific HLA-B(C) allele was found. Seven of the nine HLA-B(C) homozygotes had medium or high NK activity. No significant differences were detected in either the NK activity or in the NK subset frequencies (circulating NK cell number) between HLA-B(C) homozygous and heterozygous individuals. These results indicate that HLA-B(C) homozygosity does not always induce low NK activity and that other factors also may influence NK activities.

Adult↗
PubMed1995

Phenotypical and functional analyses of natural killer cells from low NK activity individuals among healthy and patient populations.

We investigated the deficiency of natural killer (NK) activity by contrasting healthy individuals with patients. Human NK activities of 125 individuals consisting of 68 healthy donors and 57 patients (36 autoimmune disease and 21 cancer patients) were measured by Eu-DTPA release assay in which the target cells were labeled by nonradioactive materials-Eu-DTPA, and they were phenotypically analyzed with three-color flow cytometry. Furthermore, a part of these donors was functionally studied on NK cells sorted out from PBL. 23.3% of healthy donors and approximately 70% of patients had low NK activity (LNK). In these healthy LNK and patient LNK, the population of CD3-CD16+CD56+ subset in PBL was significantly lower than that of the same subset in healthy individuals with high and medium NK activity (HMNK). The cytotoxicity of CD3-CD16+CD56+ cells sorted out from PBL in healthy LNK and patient LNK were approximately the same with or higher than that in healthy HMNK. No differences were found either in the expression of CD2 and LFA-1 antigens on the CD3-CD56+ NK cells or in the amount of granulous proteins such as perforin and granzyme A in these cells among healthy HMNK, healthy LNK and patient LNK. These results suggested that low NK activity of healthy LNK and patient LNK was more reflected by the diminution of the population of CD3-CD16+CD56+ subset in PBL rather than the functional defects of NK cells. A phenotypical and functional study on healthy LNK has not been reported extensively, and we found several differences between healthy LNK and patient LNK in this study. By stimulation with IL-2, the cytotoxicity of healthy LNK increased more rapidly than that of patient LNK, and at high effector:target cell ratio (> or = 40) it was significantly higher than that of patient LNK. The population of CD3+CD16+/CD56+ subset in PBL of healthy LNK was higher than that of patient LNK, but on the other hand it was about the same as that of healthy HMNK.

Adult↗
PubMed1985

Effect of nerve stimulation on rat skeletal muscle. A study of plasma membrane.

The gastrocnemius muscle of the rat showed no morphological, histometric or plasma membrane changes, after sciatic nerve stimulation with a 5mA current for 30 to 60 min, 10 mA for 30 min and 15 mA for 5 min. However, 10 mA for 60 and 200 min gave rise to mitochondrial and plasma membrane abnormalities. These changes were absent after a rest period. The results indicated that the sciatic nerve stimulation at 10 mA for 60 and 200 min caused reversible changes in the rat skeletal muscle mitochondria and plasma membrane.

Animals↗
PubMed1985

[G-I hormones and gastric functions--with special reference to the pyloroplasty for the selective proximal vagotomy].

UNLABELLED: Serum gastrin changes before and after selective proximal vagotomy (SPV) were studied in relation to the gastric motility and the acid secretion clinically and experimentally and the effects of pyloroplasty were investigated. RESULTS AND CONCLUSIONS: Experimental studies revealed that test meals provoked gastrin secretion to stimulate gastric motility. Periodical gastric acid secretions were observed during hunger period, along with elevated serum gastrin levels. After SPV, gastrin responses to the test meals were significantly increased so that the pyloric ring motility was disturbed. Clinical studies revealed that adrenaline infusion test provoked significant gastrin responses to secrete acid secretions in duodenal ulcer patients. After SPV, increased gastrin responses to adrenaline restored acid secretions as much as preoperative acid secretions responded to the adrenaline test. Pyloroplasty for the SPV inhibited the gastrin and acid secretions responded to the adrenaline test.

Animals↗
PubMed1984

A procedure to elongate the stomach tube in the esophageal replacement.

When the stomach tube has to be lengthened in case of antethoracic esophageal replacement, a circumferential seromuscular incision is made and the lesser curvature side of the tube is cut through, in the same line of incision. The rent produced is longitudinally suture-closed, by which a definite elongation (about 2 cm by each incision) is obtained. In our department the antethoracic use of the stomach tube has been carried out since 1968, the elongation procedure was started in 1973 as a trial, then its application became more frequent since 1978 and was performed whenever the tube seemed to be deficient in length. The stomach tube was used in 40 cases, of which 17 underwent the elongation procedure. With regard to the suture leak at the site of the antethoracic esophagogastric anastomosis, the incidence was 50 per cent from 1968 to 1972, 54 per cent from 1973 to 1977 and 22 per cent in the last 5 years. Thus, a distinct improvement has occurred with time.

Esophagus↗
PubMed1984

[Factor XIII in the treatment of postoperative refractory wound-healing disorders. Results of a controlled study].

The efficacy of factor-XIII concentrate in the improvement of postoperative wound healing disorders (suture dehiscences, fistulae) was examined in 61 patients. In an open, randomised, and controlled trial the results (decrease of wound area, signs of inflammation, wound secretion, drainage volume, contrast x-ray films, and colour photos) were evaluated twice: open judgement by the clinicians themselves and blind judgement by an independent evaluation committee. The blind evaluation of the clinical data showed relevant general improvement in the patient groups treated with factor-XIII concentrate: 61.9% (dosage: 750 IU factor XIII for 3 days) and 76.2% (dosage: 1500 IU factor XIII for 3 days) as compared to 10.5% in the control group without factor XIII substitution. The differences were significant (Mann-Whitney-U-Test, p less than or equal to 0.001). These results would suggest substituting factor XIII activity in plasma above 70% of normal value in case of wound healing disorders.

Adult↗