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Biomedical subjects

A Toshitani

Publications and source records attributed to A Toshitani.

15 recordsLinked to original sources
PubMed1999

Reduced amount of secretory component of IgA secretion in tears of patients with atopic dermatitis.

Coupled with the previous finding that sIgA excretion was reduced onto the surface of the skin, we demonstrated that sIgA secretion in the tears of patients with atopic dermatitis (AD) was significantly lower than that of normal subjects, using a small stick made of nitrocellulose membrane. In the bacterial cultures, we have also detected a higher frequency of Staphylococcus aureus in the tears from patients with AD compared to normal subjects. These findings suggested reduced sIgA secretion on the mucous membrane might play a crucial role in the pathomechanisms of the ocular lesions, such as abnormal bacterial flora and ocular complications as well as the establishment of skin lesions in AD.

Adolescent↗
PubMed1997

Sulfidoleukotriene release test (CAST) in hypersensitivity to nonsteroidal anti-inflammatory drugs.

There is a great need to develop a method for making an accurate and reliable in vitro diagnosis of adverse hypersensitivity reactions to drugs. We measured the amount of sulfidoleukotriene (sLT) released from the peripheral blood leukocytes obtained from 25 patients who developed hypersensitivity reactions following the administration of nonsteroidal anti-inflammatory drugs (NSAIDs); 12 patients demonstrated reactions to Voltaren, 8 patients to Bufferin, and 5 patients to Sedes G. The stimulation index, the ratio of the amounts of sLT (pg/ml) incubated with and without drugs, was considerably higher in the patients than in the controls, which consisted of 5 nonallergic healthy subjects. The sensitivity of the CAST (cellular antigen stimulation test) was evaluated to range from 62.5 to 80%, while the specificity was 70-100%. The CAST may thus be useful as a novel in vitro test system in order to screen for possible hypersensitive reactions to NSAIDs with both reliability and safety.

Adult↗
PubMed1996

Hair cortex comedo.

We report two cases of skin lesions that clinically resemble a comedo. Both lesions demonstrated a firm black papule which was histopathologically reminiscent of a dilated hair follicle associated with an abnormality of the hair cortex. These findings are thus considered to represent a unique and peculiar variant of the dilated pore of Winer, and the term "hair cortex comedo" is therefore believed to be suitable for such lesions.

Acne Vulgaris↗
PubMed1995

Effect of 5-(p-hydroxyphenyl)-5-phenylhydantoin (p-HPPH) enantiomers, major metabolites of phenytoin, on the occurrence of chronic-gingival hyperplasia: in vivo and in vitro study.

The purpose of this study was to assess the possible role of the (R)- and (S)- enantiomers of the phenytoin metabolite p-HPPH in the pathogenesis of gingival hyperplasia (GH). About 98% of circulating p-HPPH is in the (S)-form. There were significant differences between patients with and without GH in (R)-p-HPPH level (0.055 vs 0.042 microgram.ml-1), both enantiomer/racemate level ratios, and R/S enantiomeric ratio (0.0313 vs 0.0232); an increase in serum (R)-p-HPPH level was observed in patients with GH. In separate experiments, the effect of p-HPPH enantiomers on the proliferation of the normal human dermal fibroblast was studied. The in vitro study showed that (R)-p-HPPH selectively stimulated fibroblast growth. The results suggest that the least abundant metabolite, (R)-p-HPPH, is the most toxic with respect to gingival hyperplasia.

Adult↗
PubMed1993

Increased interleukin 6 production by T cells derived from patients with atopic dermatitis.

Many immunologic aspects of atopic dermatitis have been studied, but basic pathobiologic mechanisms of this disease remain unknown. In this study, we measured the production of interleukin-6 (IL-6) by peripheral blood T cells and monocytes from patients with atopic dermatitis in comparison to normal control subjects and patients with chronic psoriasis. We found that peripheral blood T cells isolated from patients with atopic dermatitis produced significantly higher levels of IL-6 (36.1 +/- 5.1 units/ml, n = 22) than T cells derived from either normal subjects (12.6 +/- 1.9 units/ml, n = 22) or patients with chronic psoriasis (26.7 +/- 4.1 units/ml, n = 7). T-cell activation was also measured in the patients with atopic dermatitis by soluble serum IL-2 receptor levels and were found to be significantly higher (623.7 +/- 8.1 units/ml, n = 8) than normal subjects (357.2 +/- 26.0 units/ml, n = 8). In contrast to the increased production of IL-6 by T cells in atopic dermatitis, there was no significant difference in the IL-6 production by peripheral blood monocytes derived from patients with atopic dermatitis compared to normal subjects. Thus, peripheral blood T cells derived from patients with AD spontaneously produce increased amounts of IL-6 compared to T cells from normal subjects, which may reflect the increased activation state of T cells in atopic dermatitis. These data support the concept that activated T cells or subsets of T cells may be important effector cells in mediating inflammatory activity in atopic disease.

Biological Availability↗
PubMed1993

Augmentation of in vitro cytolytic activity of LAK cells with heated ATL-derived cell lines.

Three adult T-cell leukemia/lymphoma-derived cell lines, MT-2, MJ, and HUT102, were investigated to determine how they responded to hyperthermia, lymphokine-activated killer (LAK) cells, or a combination of both in vitro. All three cell lines showed a similar sensitivity to LAK cells, but revealed varying degrees of sensitivity to hyperthermia (MT-2 < MJ < HUT102) by 51Cr release assay. Hyperthermia did not cause immediate cell death as determined by the trypan blue exclusion test, but did cause substantial decreases in the numbers of heated cells within 2 days. The density of the cells began to increase thereafter, which was consistent with the results of the experiments labeling the cells with 3H-TdR after hyperthermia. When the cells were heated at 39-43 degrees C for 1-3 hr and then interacted with various LAK cell/ATL cell (E/T) ratios at 37 degrees C for 4 hr, total cytolysis of the cells increased in a synergistic and/or additive manner over that of the cells without hyperthermia. Prolonged incubation of the cells at high temperature did not necessarily cause a large increase in the interaction of LAK cells after hyperthermia. This augmentation of cytolysis by LAK cells after hyperthermia was not seen in normal peripheral lymphocytes. These results suggest that the combination therapy of hyperthermia and LAK cells may be more specific, useful, and effective for treating malignant lymphoma.

Cytotoxicity, Immunologic↗
PubMed1992

Synergistic effects of interleukin 4 and interferon-gamma on monocyte phosphodiesterase activity.

Patients with atopic dermatitis (AD) have elevated leukocyte cyclic AMP-phosphodiesterase (PDE) activity and increased in vitro IgE synthesis compared to normal (NL) subjects. Interleukin 4 (IL-4), interferon-gamma (IFN-gamma), and PDE inhibitor have been shown to regulate in vitro IgE synthesis. This study investigated whether soluble T-cell factors such as IL-4 and IFN-gamma could account for elevated PDE activity in patients with AD. Both rhIL-4 and IFN-gamma significantly increased normal monocyte PDE activity to a maximum of 188% (n = 6, p less than 0.05) and 315% above control (n = 3, p less than 0.05), respectively. At concentrations below 0.1 units/ml IL-4 and IFN-gamma had synergistic effects on activation of monocyte PDE. AD and NL T-cell culture supernatants also significantly stimulated normal monocyte PDE activity, but the stimulatory activity was not significantly greater in the AD T-cell supernatants. The effect of both cytokines and T-cell supernatants on normal monocytes was inhibited by antibodies against IL-4 and IFN-gamma, respectively. This study demonstrates that IL-4 and IFN-gamma can increase PDE activity in normal monocytes. Though the levels of IL-4 and IFN-gamma in T-cell supernatants are undetectable with an enzyme-linked immunosorbent assay (ELISA) assay, the concentration of these cytokines below the detectable level can significantly increase PDE activity of monocytes in a synergistic and dose-dependent manner. These results suggest that cytokine-mediated activation of monocytes can increase PDE activity. Furthermore, lymphokines may play an important role in modulating the cyclic nucleotide regulatory pathway.

Dermatitis, Atopic↗
PubMed1992

Responses of B16 melanoma cell lines, F1 and F10, to hyperthermia, lymphokine-activated killer cells and a combination of both in vitro.

The cytolytic and/or cytostatic effects of hyperthermia, lymphokine-activated killer cells (LAK cells) and the combination of both were assayed using F1 and F10 B16 melanoma cell lines. F10 cells with a high metastatic potential showed a greater sensitivity to hyperthermia than F1 cells which have low metastatic potential. The F10 cells were lysed to a lesser extent by LAK cells than the F1-B16 cells. When the cell lines were subjected to hyperthermia at 43 degrees C for 3 h and then interacted with LAK cells, the maximum cytolysis reached almost 100%. When the interaction with LAK cells was followed by hyperthermia at 43 degrees C, the total release of 51Cr from the cell lines was 75-85%. The extent of 51Cr release from the B16 melanoma cell lines was inversely correlated with the survival rate as calculated by the plating efficiency of the incubated cells. The survival rate of mice intravenously injected with B16-F10 cells and subjected to hyperthermia at 41 degrees C for 3 h in vitro increased compared to that of controls. This was further increased by the simultaneous administration of LAK cells.

Animals↗
PubMed1989

Anti-metastatic effect by in vivo administration of concanavalin A through augmentation of T-derived activated killer activity: efficacy to B16 melanoma expressed MHC antigen.

We attempted to investigate if the in vivo administration of concanavalin A (Con A), a potent T cell stimulator, would render anti-metastatic activity in hosts. Assays of activity were performed 20 days after iv inoculation of two clones of the B16 melanoma, B16-H (H-2+, highly metastatic), B16-L (H-2-, low metastatic), or 3LL cells into C57BL mice by enumerating lung colonies. In some experiments, hosts treated with anti-asialo GM1 Ab were used to evaluate effector mechanisms other than NK cells. While the injection of Con A alone had no significant effect on anti-metastatic activity, in nonimmunized hosts the effect by Con A was displayed when the mice were preimmunized with B16-H cells but not in those immunized with B16-L cells. Immunization with B16-H or B16-L cells alone resulted in the generation of killer cells with promiscuous lytic activity and induced an anti-metastatic effect against B16-H, B16-L, and 3LL cells. Con A treatment significantly augmented the killer activity of spleen cells of mice preimmunized with B16-H cells but not of those immunized with B16-L cells. The effectors from mice immunized with B16-H alone or given both Con A and B16-H were mainly of Thy 1+ Lyt2+ asialo GM1- cells, on the other hand, those from mice immunized with B16-L cells expressed asialo GM1 antigen. We showed the efficacy of Con A on the anti-metastatic effect in relation to the host immune response.

Animals↗
PubMed1988

Host H-2 genotype regulates the metastatic ability of H-2-associated variants of B16 melanoma: defense systems screening for absence of self H-2 components by natural killer cells and host-associated homing barrier.

The mechanisms of host H-2-associated resistance against metastasis of tumor cells were evaluated in relation to the H-2 phenotype of tumor cells. We used H-2 heterozygous H-2a/b and H-2d/b, and H-2 homozygous H-2b/b hosts, and H-2-associated variant lines of B16 cells (H-2b+, H-2b-). In H-2b/b hosts, H-2+ cells were highly metastatic in vivo, and were resistant to host NK effectors in vitro. Therefore, H-2a/b and H-2d/b hosts showed resistance to metastasis of H-2+ cells and their effectors showed killing activity to these cells in vitro. Though the host resistance was reduced by anti-asialo GM1 serum treatment, these hosts continued to demonstrate a considerable resistance against early survival and metastasis of the B16 cells. To evaluate this natural resistance, aside from the NK system, radiation bone marrow chimeras of F1-parental combinations were used. The data suggest that host MHC-associated resistance involves not only the NK defense system but also the host environmental resistance. Both exert resistance by recognizing the H-2 mismatch in relation to the host.

Animals↗
PubMed1988

Adoptive transfer of H-2-incompatible lymphokine-activated killer (LAK) cells: an approach for successful cancer immunotherapy free from graft-versus-host disease (GVHD) using murine models.

We investigated whether the adoptive transfer of H-2-incompatible lymphokine-activated killer (LAK) cells would efficiently demonstrate antitumor activity without damaging the normal host cells. Allogeneic LAK cells (5 X 10(7] did not cause graft-versus-host disease (GVHD) in irradiated recipients, whereas more than half of the mice transferred with the same dose of fresh allogeneic spleen cells developed GVHD. Repeated transfer (three times at 4-day intervals, 1.2 X 10(8) cells/mouse) did not result in GVHD. Graft-versus-host reaction (GVHR), which is detectable by spleen enlargement of recipients transferred with allogeneic lymphoid cells was also absent in LAK cell-transferred mice of all strain combinations tested. Host immune responses were not affected in these mice. Therefore, it is feasible to transfer allogeneic LAK cells. With the antitumor efficacy of allogeneic LAK cells, they preferentially lysed allogeneic tumor targets. Adoptive transfer of the allogeneic LAK cells led to a significant decrease in the lung-colonizing foci of intravenously inoculated B16 melanoma cells. Allogeneic LAK cells and syngeneic ones were equally active, in vivo. The use of allogeneic LAK cells may prove to be a valuable method for effective clinical antitumor immunotherapy.

Animals↗
PubMed1988

Does depression of NK activity cause lymphadenopathy in lpr mice?

B6-lpr/lpr mice develop massive T cell lymphoproliferation, as associated with autoimmune disease. We found a reduced NK activity in the spleen of B6-lpr/lpr mice. Neonatal thymectomy markedly retarded the development of lymphoproliferation and the development of autoantibodies in the B6-lpr/lpr mice. These animals had a higher level of NK activity in the spleen. When the neonatally thymectomized B6-lpr/lpr mice were given anti-asialo GM1 serum (30 microliter) four times at 6-day intervals, initiated at the 8th-10th postnatal week, these mice developed lymphoproliferative disorders and splenomegaly, concomitantly with depression of NK activity. It is therefore tempting to speculate that NK cells are involved in the regulation of the occurrence of lymphoproliferative disorders.

Animals↗
PubMed1987

Inverse relationship in H-2-associated lysis between NK cells and rIL-2-activated killer cells: evidence from in vitro killing and metastatic experiments.

We investigated the manner in which rIL-2 induced effectors in vitro (LAK cells), which, like NK cells, lyse targets nonspecifically and discriminate nonself, and how H-2 as the self-marker affects the LAK cell killing mechanism. NK cells showed an appreciably higher killing activity to B16 melanoma H-2- cells than to H-2+ cells. In contrast, LAK cells lysed more efficiently to H-2+ cells. The in vivo experiments showed that the NK cells prevented pulmonary metastasis of B16 H-2- cells in the normal syngeneic host, whereas the transferred LAK cells had a preferential inhibitory effect on the pulmonary metastasis of B16 H-2+ cells in the immunodeficient syngeneic hosts. Taken together, these results show that the H-2-encoded or H-2-associated molecules contribute to the triggering signal in the lysis by LAK cells, whereas the NK cells recognize the reduced self H-2 expression on the targets, thereby contributing to a trigger of the lysis.

Animals↗
PubMed1986

Synergistic defense system by cooperative natural effectors against metastasis of B16 melanoma cells in H-2-associated control: different behavior of H-2+ and H-2- cells in metastatic processes.

H-2+ and H-2- cells of B16 melanoma were established by repeated fluorescence-activated cell sorting. The H-2- line formed no metastasis in untreated C57BL/6 mice, whereas the H-2+ cells showed evidence of metastatic development. This difference was ascribed mainly to the increased susceptibility of H-2- cells to attack by natural effector mechanisms, particularly asialo GM1+ NK cells. After treatment with both anti-asialo GM1 serum and whole body irradiation (400 rad), numerous colonies of H-2- cells formed in the lung, whereas the metastasis was only marginally enhanced by irradiation and moderately by treatment with anti-asialo GM1 serum. With the H-2+ cells, treatment with each modality significantly increased the number of metastatic colonies. Therefore collaboration of asialo GM1+ NK cells and radiosensitive natural effectors seems to be the main mechanism involved in the synergistic effects on defense against H-2- cell metastasis, and to a lesser extent against H-2+ cell metastasis. Irradiation (1000 rad) to the right lung to abrogate the organ-associated defense increased the colonies, particularly in the H-2+ cells. On the other hand, treatment with anti-asialo GM1 serum increased colonization in the early phase of metastasis with H-2- cells and may have abolished asialo GM1+ NK cells capable of recognizing the reduced expression of H-2 antigens and eliminating H-2- cells in the blood-born phase. Natural defense mechanisms probably exert suppressive effects on the metastasis of H-2+ cells, mainly in the organ-associated phase after extravasation.

Animals↗