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Biomedical subjects

A Nakata

Publications and source records attributed to A Nakata.

At least 163 records · Page 9Linked to original sources
PubMed1971

Location and orientation of the phoA locus on the Escherichia coli K-12 linkage map.

The order of gene loci in the phoA-phoR region of the Escherichia coli K-12 linkage map was demonstrated to be lac phoA proC phoR. The end of the phoA locus corresponding to the amino terminus of alkaline phosphatase was shown to be the end nearer proC. Translation (and transcription) of phoA is therefore in the anticlockwise direction relative to the conventional E. coli linkage map.

Alkaline Phosphatase↗
PubMedDate not supplied

Fatal septic complication of transcatheter chemoembolization for hepatocellular carcinoma.

A patient with hepatocellular carcinoma, associated segmental portal vein thrombosis, and accompanying pneumobilia, developed a liver abscess and sepsis following transcatheter chemoembolization (TCE). It was believed that the combination of bile duct necrosis after arterial occlusion and pneumobilia led to ascending enteric infection and seeding of the necrotic tumor, which ultimately led to fatal outcome. We conclude that TCE is contraindicated in such cases.

Carcinoma, Hepatocellular↗
PubMedDate not supplied

Decreases of natural killer cells and T-lymphocyte subpopulations and increases of B lymphocytes following a 5-day occupational exposure to mixed organic solvents.

The authors examined the effects of organic solvents on lymphocyte subpopulations in blood. Natural killer and T-lymphocyte subpopulations and B (CD19+) -lymphocytes were measured with flow cytometry in 16 male rotogravure printers on a Friday and on the following Monday. Numbers of all 3 subpopulations of natural killer cells (i.e., CD57+ CD16+, CD57- CD16+, and CD57+ CD16- cells), 2 subpopulations of T lymphocytes (CD4+ CD45RA+ and total CD8+ cells), and total lymphocytes on Friday were significantly fewer than those found on the following Monday. Conversely, the number of B lymphocytes on Friday was significantly larger than the number on Monday. The number of B lymphocytes was significantly correlated with blood toluene levels on Friday. The alteration in the number of CD57+ CD16+ NK cells from Friday to the following Monday was correlated inversely with the corresponding change in exposure level of toluene on Friday. The authors suggest that the effects of mixed organic solvents (primarily toluene) are recoverable decreases of natural killer cells and T lymphocytes and increases in B lymphocytes.

Adult↗
PubMedDate not supplied

Increase in memory (CD4+CD29+ and CD4+CD45RO+) T and naive (CD4+CD45RA+) T-cell subpopulations in smokers.

To examine the effects of smoking on lymphocyte subpopulations, we measured the following cell subpopulations: CD4+ T-cell subpopulations (i.e., CD4+CD29+, CD4+ CD45RO+, and CD4+CD45RA+ cells); CD8+ T-cell subpopulations (i.e., CD8+CD11a+ and CD8+CD11b+ cells); and natural killer cell subpopulations (i.e., CD16+CD57-, CD16+CD57+, and CD16-CD57+ cells). We measured these subpopulations, together with total CD4+ T, total CD8+ T, total CD3+ T, B (CD19+), and total lymphocytes, in 10 male heavy smokers, 38 male light-to-moderate smokers, and 33 male nonsmokers. The mean ages were 30 y, 31 y, and 32 y, respectively, and ages did not vary significantly among the smokers. CD4+CD29+ and CD4+CD45RO+ (memory T) cells in heavy smokers were significantly more numerous than those in light-to-moderate smokers and nonsmokers. Also, these memory T-cell subpopulations were significantly more numerous in light-to-moderate smokers than in nonsmokers. The number of CD4+CD45RA+ (naive T) cells was significantly larger in heavy smokers than nonsmokers; numbers of CD4+CD45RO+ T and CD4+CD29+ T cells (memory T cells) were significantly correlated with daily cigarette consumption. Numbers of CD3+ T, CD4+ T, CD19+ B, and total lymphocytes in heavy smokers were significantly larger than in nonsmokers. There were significantly more CD3+ T, CD4+ T, and total lymphocytes in light-to-moderate smokers than in nonsmokers. The numbers of CD4+ T lymphocytes in heavy smokers were significantly larger than in light-to-moderate smokers. Perhaps CD4+ T cell subpopulations, especially memory T cells, are most susceptible to the effects of smoking on lymphocyte subpopulations.

Adult↗
PubMedDate not supplied

Effects of smoking and Japanese cedar pollinosis on lymphocyte subpopulations.

Approximately 10-30% of the Japanese population suffer from Japanese cedar (Cryptomeria japonica) pollinosis in the spring. To date, the effects of this pollinosis on lymphocyte subpopulations have not been examined epidemiologically. To examine the effects of smoking and Japanese cedar pollinosis on lymphocyte subpopulations, we used flow cytometry to measure CD4+ and CD8+ T-lymphocyte subpopulations, natural-killer cell subpopulations, B(CD19+) lymphocytes, and total lymphocytes in 61 smokers and 51 nonsmokers. Some of these individuals had histories of pollinosis during November 1993-an off-season for Japanese cedar pollination. Our findings suggested that (a) CD4+ T-lymphocyte subpopulations (i.e., CD4+CD29+, CD4+CD45RA+, and CD4+ CD45RO+ cells) together with total CD4+ T, total T, and total lymphocytes, were increased by the effects of smoking; (b) CD8dim+CD11a+T, and CD8+CD11bt, and CD57+CD16+ natural killer cells, together with total CD8+CD11 a+ T and total CD8+ T lymphocytes, were increased by the effects of pollinosis on smokers, even though no lymphocyte subpopulations were increased by only the pollinosis effects; (c) CD4+CD29+T and CD8dimCD11a+ T lymphocytes were increased by the effects of smoking on pollinosis, and (d) CD4+CD29+ T and CD4+CD45RO+ T lymphocytes, CD8dim+CD11 a+ T, and CD8+CD11b+ T lymphocytes and CD57+CD16+ natural killer cells, together with total CD4+ T, total T (CD3+), total CD8+CD11a+, total CD8+ T, and total lymphocytes, were increased by the combined effects of smoking and pollinosis.

Adult↗
PubMedDate not supplied

Cloned Th cells confer eosinophilic inflammation and bronchial hyperresponsiveness.

BACKGROUND: The essential role of Th cells and T cell cytokines in eosinophilic inflammation has been established. METHODS: To determine whether Th cells are sufficient for the development of airway eosinophilic inflammation, ovalbumin-reactive murine Th clones were established and infused into unprimed mice. RESULTS: Eosinophilic infiltration into the lung was induced upon antigen inhalation in parallel with the rise in bronchoalveolar lavage fluid (BALF) eosinophil peroxidase activity. Neither IgG, IgA, nor IgE antibodies were present in this model. Pathological examination showed swelling and desquamation of epithelial cells, mucous plugs, and goblet cell hyperplasia, all of which well resemble human asthma. Fluorescent probe labeled Th clones migrated into the lung prior to the eosinophil accumulation. Bronchial hyperresponsiveness (BHR) was clearly induced upon antigen inhalation. Anti-IL-5 monoclonal antibody abrogated the responses. Dexamethasone and cyclosporin A suppressed cytokine production by Th cells both in vitro and in vivo, BALF eosinophilia, and BHR. The number of eosinophils recovered in the BALF correlated with the intensity of BHR. CONCLUSION: The results clearly indicated that monoclonal Th cells are sufficient for the development of both airway eosinophilia and BHR. Agents capable of downregulating IL-5 production seem promising for the treatment of bronchial asthma.

Animals↗
PubMedDate not supplied

Differential effects of neuropeptides on cytokine production by mouse helper T cell subsets.

Though immune outcome is known to be determined by which helper T cell response predominates, no local mechanism has yet been established which can explain how the neuronal system may control this. It is possible that the nervous system releases neuropeptides at specific local sites of infection or challenge, which triggers lymphocytes at those points to release specific cytokine profiles. These may then influence the direction of the Th1/Th2 response and therefore immune outcome. The aim of this study was to evaluate whether and if so how neuropeptides influence cytokine production by lymphocytes, especially T cells. We investigated the effects of neuropeptide Y (NPY), calcitonin gene-related peptide (CGRP), substance P (SP) and vasoactive intestinal peptide (VIP) on the production of interferon-gamma (IFN-gamma) and interleukin-4 (IL-4) by stimulating nonadherent splenocytes and helper T cell clones with antigens in vitro in the presence or absence of these peptides. NPY greatly enhanced IL-4 production and inhibited IFN-gamma. CGRP inhibited IFN-gamma production markedly in a dose-dependent manner, but had no effects on IL-4 production. SP and VIP had no effects on IFN-gamma production, but SP enhanced and VIP suppressed IL-4 production slightly but consistently. Therefore neuropeptides can influence cytokine production. This opens the door to speculations that these specific cytokine profiles might play a part in influencing the direction of the consequent Th1/Th2 cascade and immune outcome and possibly the pathogenesis of immune-related diseases.

Animals↗
PubMedDate not supplied

Effects of uncontrollable and controllable electric shocks on T lymphocyte subpopulations in the peripheral blood, spleen, and thymus of rats.

To examine the effects of uncontrollable and controllable electric shocks on the immune system in rats, the proportion of CD4+, CD8+ or CD25+ T lymphocytes to total lymphocytes was measured in the peripheral blood, spleen, and thymus. The rats were given either controllable shocks, identical uncontrollable shocks, or no shocks, and then small shocks 24 h later (reinstating shocks). The proportion of CD4+ T lymphocytes relative to total lymphocytes in both the peripheral blood and spleen of uncontrollable rats (URs) was significantly smaller than was found in no-shock rats (NRs). Similarly, the proportion of CD4+ T lymphocytes in the thymus of controllable rats (CRs) was significantly smaller than in NRs. In contrast, the proportion of CD8+ T lymphocytes in the thymus of URs was significantly larger than in NRs and CRs. The CD4+ to CD8+ T lymphocyte ratios (CD4+/CD8+ ratios) in the peripheral blood, spleen and thymus of URs were significantly smaller than in NRs; also, the ratios in the peripheral blood and spleen of URs were significantly smaller than in CRs. The white blood cell (WBC) count of URs was significantly smaller than those of NRs and CRs, and the WBC count of CRs was significantly smaller than those of NRs and CRs, and the WBC count of CRs was significantly smaller than that of NRs. These results suggest that decreases in CD4+ T lymphocytes (and/or an increase of CD8+ T lymphocytes) in the peripheral blood, spleen, and thymus are caused by uncontrollable stress followed by a reinstating stress condition, leading to the decrease of WBC in the peripheral blood and decreases in the CD4+/CD8+ ratios in these tissues.

Animals↗
PubMedDate not supplied

Naïve (CD4+CD45RA+) T cell subpopulation is susceptible to various types of hazardous substances in the workplace.

To find the most susceptible lymphocyte subpopulation with exposure to various occupational hazardous substances, we reanalyzed our previous data. We measured T, B and natural killer NK cell subpopulations by means of flowcytometry among workers who were exposed to aromatic amines, chromate, mercury lead and organic-solvents. The exposed/non-exposed ratio was defined as the mean value of the absolute number of lymphocyte subpopulations in the exposed workers divided by the corresponding value of the non-exposed control group in 5 studies reported previously by us. The ratio of CD4+CD45RA+ T cells in all the exposed groups examined in this study was less than 1.0, and the mean of these ratio was 0.77, which was the lowest among lymphocyte subpopulations examined. The mean ratio was 1.06 for CD4+CD29+ T cells, 0.91 for CD4+ T cells, 0.99 for CD8+ T cells, 0.93 for CD3+ T cells, 0.99 for CD19+B cells, 0.96 for CD57-CD16+ NK cells, 0.82 for CD57+CD16+ NK cells, 1.25 for CD57+CD16- NK cells and 0.89 for total lymphocytes. With regard to the difference between exposed and non-exposed workers the estimated overall difference in the mean absolute number of CD4+CD45RA+ T cell subpopulation between exposed and non-exposed workers among five studies was -135 ((% confidence interval, CI: (-194,-75)) cells/mm3 (p<0.01). In conclusion, naïve (CD4+CD45RA+) T cell subpopulation was the most susceptible to the effects of various toxic substances as compared with other lymphocyte subpopulations. This lympohocyte subpopulation may be useful for monitoring immune system of workers exposed to various types of substances in the workplace.

Adult↗