Interference Effect between ϕ and Λ(1520) Production Channels in the γp→K

The ϕ-Λ(1520) interference effect in the γp→K^{+}K^{-}p reaction has been measured for the first time in the energy range from 1.673 to 2.173 GeV. The relative phases between ϕ and Λ(1520) production amplitudes were obtained in the kinematic region where the two resonances overlap. The measurement results support strong constructive interference when K^{+}K^{-} pairs are observed at forward angles but destructive interference for proton emission at forward angles. Furthermore, the observed interference effect does not account for the sqrt[s]=2.1 GeV bump structure in forward differential cross sections for ϕ photoproduction. This fact suggests possible exotic structures such as a hidden-strangeness pentaquark state, a new Pomeron exchange, or rescattering processes via other hyperon states.

Effects of short-term intensive glycemic control on insulin, glucagon, and glucagon-like peptide-1 secretion in patients with Type 2 diabetes.

BACKGROUND: Short-term intensive insulin therapy (IIT) in patients with Type 2 diabetes mellitus (T2DM) has beneficial effects on insulin secretion. However, IIT effect on glucagon and glucagon-like peptide-1 (GLP-1) secretion is unknown. AIM: We evaluated short-term intensive glycemic control effects on insulin, glucagon, and GLP-1 secretory dynamics in T2DM. MATERIALS AND METHODS: Twenty-six patients with T2DM were hospitalized and treated with IIT for 10-14 days. A meal tolerance test was performed before and after IIT and the differences in serum immunoreactive insulin (IRI) and C-peptide immunoreactivity (CPR) as well as plasma glucagon and active GLP-1 levels were evaluated. RESULTS: Glycoalbumin levels decreased significantly from 23.0% before to 19.6% after IIT (p<0.001). However, pre- and post-IIT, IRI and CPR levels were not significantly different; post-IIT glucose levels were significantly decreased. The post-IIT glucagon levels at 0 and 60 min were lower than pre-IIT levels. Moreover, post- IIT area under the curve (AUC) of glucagon significantly reduced from 6755 ± 996 pg/dl · 60 min to 5796 ± 1074 pg/dl · 60 min (p<0.001). Furthermore, post-IIT GLP-1 levels and AUC were significantly higher than pre-IIT values. CONCLUSIONS: Our results suggest that patients with T2DM who received shortterm IIT demonstrated decreased postprandial glucagon levels and increased GLP-1 levels following a meal tolerance test.

Suppressive effect of asbestos on cytotoxicity of human NK cells.

Asbestos, a naturally occurring fibrous mineral, causes malignant mesothelioma (MM). However, it takes a very long time to develop MM, which suggests that effects other than tumorigenicity of asbestos might contribute to the development of MM, and one of the possible targets is anti-tumor immunity. Therefore, we examined the effect of asbestos exposure on human natural killer (NK) cells using the cell line of YT-A1, Peripheral blood mononuclear cells (PBMCs) cultures and specimens from patients with MM. In particular, we focused on expression of NK cell-activating receptors, including NKG2D, 2B4 and NKp46. Analysis of the YT-CB5 subline of YT-A1, cultured with CB for over 5 months, showed a decrease in cytotoxicity with low expressions of NKG2D and 2B4, although there were no decreases after about one month. YT-CB5 showed decreases in phosphorylation of extracellular signal-regulated kinase (ERK) and degranulation stimulated by antibodies to NKG2D. Peripheral blood (PB-) NK cells from MM patients also showed decreased cytotoxicity compared with healthy volunteers (HV), and was accompanied with low expression of NKp46 unlike YT-CB5. PBMCs cultured with CB resulted in decreased expression of NKp46 on NK cells, although this did not occur when using glass wool, an asbestos substitute. These results indicate that asbestos has the potential to suppress cytotoxicity of NK cells. In particular, it is noteworthy that both NK cells from MM patients and those from a culture of PBMCs derived from HVs with asbestos showed the same characteristic of decreased cytotoxicity with low expression of NKp46.

Dysregulation of autoimmunity caused by silica exposure and alteration of Fas-mediated apoptosis in T lymphocytes derived from silicosis patients.

Silicosis patients suffer from pulmonary fibrosis caused by silica inhalation, as well as autoimmune diseases known as the adjuvant effects of silica. Caplan syndrome complicated with rheumatoid arthritis (RA) is well known epidemiologically, and the incidence of complicated systemic sclerosis (SSc), systemic lupus erythematosus (SLE) and antineutrophilic cytoplasmic antibody (ANCA)-related nephritis have been reported frequently in silicosis patients. To explore the detailed mechanisms of silica-induced dysregulation of autoimmunity, we had focused on Fas/CD95 and Fas-mediated apoptosis because Fas is one of the most important molecules regarding apoptosis of lymphocytes and its alteration makes some T cells survive longer. Additionally, if the long-survived T cells include the self-recognizing T-cell clones, it is easily thought that autoimmune diseases will appear in this situation. Furthermore, regulatory T cells (Treg) showing CD4+25+ and forkhead box P3 (FoxP3)-positive have been a central player in regulating activation of self- and foreign-antigen recognizing T cells, and it has been reported that activation of Treg causes its higher expression of Fas/CD95. Thus, in this review, we introduce the alteration of Fas and related molecules as found in silicosis and also present the Treg function of the CD4+25+ fraction in peripheral blood mononuclear cells derived from silicosis patients.

Near-threshold Lambda(1520) production by the gamma(p)-->K{+}Lambda(1520) reaction at forward K+ angles.

Differential cross sections and photon-beam asymmetries for the gamma(p)-->K{+}Lambda(1520) reaction have been measured with linearly polarized photon beams at energies from the threshold to 2.4 GeV at 0.6or=5/2 or by a new reaction process, for example, an interference effect with the phi photoproduction having a similar bump structure in the cross sections.

Reductive alteration of the regulatory function of the CD4(+)CD25(+) T cell fraction in silicosis patients.

Causal links have been documented between silica and rheumatoid arthritis, lupus erythematosus, systemic sclerosis and glomerulonephritis. Two different effects of silica have been suggested, an enhanced inflammatory response in the pulmonary region (e.g. activation of alveolar macrophages) and dysregulation of autoimmunity. Based on our previous reports showing in vitro activation of peripheral T cells by silica and reduced regulatory function of the peripheral CD4(+)CD25(+) fraction in which FoxP(3)+ regulatory T cells (Treg) are located, reconstitution of the CD4(+)CD25(+) fraction in silicosis patients (SILs) was investigated. Since T cells in peripheral CD4(+)CD25(+) and CD4(+)CD25(-) (effector T cells; Teff) fractions from SILs showed higher expression of pd-1 (a marker gene for T cell activation) in comparison to that of healthy donors (HDs), chronic T cell activation was considered to have occurred in SILs. In this study, a higher expression of the CD95/Fas molecule in Treg was recorded from silicosis patients (SILs) compared to healthy donors (HDs), and excess loss of FoxP3(+) Treg in freshly isolated peripheral blood mononuclear cells (PBMCs) from SILs relative to HDs was demonstrated when these cells were cultured with silica ex vivo, whereas CD25(+) cells were not reduced due to contamination of activated Teff in the CD4(+)CD25(+) fraction. The activation of both Teff and Treg results in reconstitution of the peripheral CD4(+)CD25(+) fraction, loss of Treg and contamination of activated Teff, resulting in reduction of the number and function of Treg. These results contribute to our understanding of the development of autoimmune diseases found in SILs.

Decrease in phosphorylation of ERK following decreased expression of NK cell-activating receptors in human NK cell line exposed to asbestos.

YT-CB5, which had been continuously cultured with chrysotile B (CB)asbestos, showed impaired cytotoxicity with decreased expression of NKG2D and 2B4 NK cell-activating receptors. In the present study, the phosphorylation of extracellular signal-regulated kinase (ERK), which is known to induce degranulation downstream of many NK cell-activating receptors, was examined in YT-CB5 by flow cytometry and compared with the control line YT-Org. YT-CB5 exhibited impaired phosphorylation of ERK1/2 induced by the recognition of K562 cells, downstream of a process mediated by Src family kinase and phosphoinositide 3-kinase. YT-CB5 also exhibited impaired phosphorylation of ERK1/2 following incubation with K562 cells in the presence of anti-2B4 antibodies, where co-stimulation by 2B4 augmented the phosphorylation of ERK1/2 in YT-CB5 to a similar degree as in YT-Org. The phosphorylation of ERK1/2 induced by an inhibitor against phosphatase (PP) 1 and PP2A was also lower in YT-CB5 compared with YT-Org. Moreover, bead-bound antibodies to NKG2D, which contribute to cytotoxicity against K562 cells, induced negligible phosphorylation of ERK1/2 in YT-CB5, although antibodies to 2B4 induced a comparatively greater level of phosphorylation. Additionally, peripheral blood (PB-) NK cells with low expression of NKG2D showed lower phosphorylation of ERK1/2 mediated by anti-NKG2D antibodies compared with PB-NK cells with high expression of NKG2D. These results indicate that signal transduction events leading to the phosphorylation of ERK is impaired in YT-CB5 due to decreased expression of NKG2D. Further studies are required to clarify whether this suppressive effect of asbestos exposure on NK cells might promote lung cancer and mesothelioma in people who have inhaled asbestos.

Impairment in cytotoxicity and expression of NK cell- activating receptors on human NK cells following exposure to asbestos fibers.

Asbestos is well-known for its tumorigenic activity, but its effect on anti-tumor immunity remains unclear. Therefore, we prepared a sub-line of YT-A1 human NK cells exposed to chrysotile B (CB) asbestos (YT-CB5) as an in vitro model to analyze the effect of asbestos exposure on NK cells, and examined cytotoxicity and expressions of its related molecules. The cytotoxicity of YT-CB5 against K562 cells decreased compared with the original line of YT-A1 (YT-Org). YT-CB5 exhibited significant decreases in expressions of cell surface NKG2D, 2B4 and intracellular granzyme A. YT-CB5 also exhibited a decrease in the 2B4-dependent cytotoxicity. In addition, the degranulations stimulated via cell surface NKG2D and 2B4 also decreased in YT-CB5. Therefore, peripheral blood NK cells in patients with malignant mesothelioma (MM) were examined and compared with healthy volunteers. NK cells in patients with MM also showed decreases in cytotoxicity against K562. Although the expressions of NKG2D and 2B4 did not decrease in NK cells of MM patients, the expression of cell surface NKp46 decreased. To confirm the effect of asbestos exposure on peripheral blood NK cells, PBMCs were cultured under exposure to CB. NK cells in PBMCs exposed to CB in vitro showed a significant decrease in the expression of NKp46, whereas NK cells and alter the expression of NK cell-activating receptors including NKG2D, 2B4 and NKp46 and intracellular perforin/granzymes.cells in PBMCs exposed to glass wool did not show such a decrease. These results indicate that exposure to asbestos has the potential to impair the cytotoxicity of NK cells and alter the expression of NK cell-activating receptors including NKG2D, 2B4 and NKp46 and intracellular perforin/granzymes.

Soluble interleukin-2 receptor as an indicator of immunological disturbance found in silicosis patients.

Silicosis patients (SILs) possess not only respiratory disorders but also alterations in autoimmunity. To determine an early indicator of immunological disturbance in SILs, the role of serum-soluble interleukin (IL)-2 receptor (sIL-2R) was analyzed. Of ten SILs, immunological clinical parameters such as immunoglobulin (Ig) G, complements, the titer of autoantibodies including anti-nuclear antibodies (ANA), anti-Scl-70 antibody (Ab) and anti-centromere (CM) Ab, and experimental indicators such as serum-soluble Fas, serum IL-2, CD25+ cells in CD4+ or CD8+ fractions, and sIL-2R were divided from respiratory parameters such as percent vital capacity (%VC), percentage of forced expiratory volume in 1 second (FEV1.0%) and v25/Ht (liter/second/m(body height) by a correlation assay. Additionally, a stepwise regression test showed that sIL-2R was correlated with Ig G, ANA and anti-CM Ab. Furthermore, factor analysis revealed that sIL-2R contributed to the subpopulation of SILs with poorer immunological status in the absence of alterations in respiratory status. By defining healthy donors as 1, SILs as 2 and patients with systemic sclerosis as 3 for immunopathological progression status as metric variables, sIL2R and ANA showed a strong positive correlation. This suggests that sIL-2R is a good clinical indicator of immunological disturbance found in SILs without clinical manifestations of any disturbance in autoimmunity. Further analysis using a large-scale number of patients should be performed to confirm these findings.

Two weeks of permanence in negatively-charged air conditions causes alteration of natural killer cell function.

The effects of negatively-charged air conditions were analyzed as one of the approaches to improve health and quality of life. We previously reported that the use of a charcoal coating and application of an electric voltage yielded predominantly negatively-charged particles in an experimental room, and that 2.5 hours of living in these conditions caused a slight activation of the immune system (slight elevation of serum interleukin (IL)-2), regulated blood flow, and stabilized the autonomic nervous system when compared with control conditions (no dominance of negatively-charged particles). In this study, we expanded the previous study and placed 15 subjects in negatively-charged air conditions for two weeks during the night and analyzed various biological parameters. Although individual biological reactions differed from subject to subject, natural killer (NK) cell activity increased significantly following living in negatively-charged air conditions. Taken together, the results of the previous investigation and those of this study show that repeated elevation of IL-2 (although it immediately returned to the baseline level) causes chronic and recurrent stimulation to NK cells and results in the steady activation of NK cells. Negatively-charged air particles may be a good tool to improve health and quality of life.

Increase of Q-factor in photonic crystal H1-defect nanocavities after closing of photonic bandgap with optimal slab thickness.

We investigate the dependence of quality factor Q of dipole modes in photonic crystal H1-defect nanocavity on the slab thickness and observe an increase of Q even after closing of the photonic bandgap both in numerical simulation and experimentation. This counter intuitive behavior results from the weak coupling between the cavity mode and the 2nd-guided mode in the photonic crystal slab. This is confirmed by computing the overlap between them in the momentum space.

Interleukin 10 and transforming growth factor beta contribute to the development of experimentally induced allergic conjunctivitis in mice during the effector phase.

AIM: To investigate the involvement of interleukin (IL)10 and transforming growth factor (TGF) beta in the development of experimentally induced allergic conjunctivitis in mice. METHODS: Balb/c mice were actively sensitised with ragweed in alum, and then challenged with ragweed in eye drops after 10 days. 24 h later, the conjunctivas, spleens and blood were collected for histological and cytokine expression analyses, proliferation and cytokine production assays and measurement of immunoglobulin (Ig) levels. Mice developing experimentally induced allergic conjunctivitis were injected intraperitoneally with 200 microg of anti-IL10 or anti-TGF beta antibodies at 0, 2, 4, 6 and 8 days (induction phase treatment) or 500 microg of antibodies 2 h before ragweed challenge (effector phase treatment). Normal rat IgG was used for control injections. RESULTS: Treatment with either anti-IL10 or anti-TGF beta antibodies during the induction phase did not affect eosinophil infiltration into the conjunctiva. By contrast, treatment with either antibody during the effector phase suppressed infiltration. During the effector phase, treatment with anti-TGF beta antibody, but not the anti-IL10 antibody, markedly up regulated proliferation and Th2 cytokine production by splenocytes. IL1alpha levels in the conjunctiva were reduced after treatment with either antibody; in addition, eotaxin and tumour necrosis factor alpha levels were reduced after treatment with antibody to TGF beta. CONCLUSIONS: IL10 and TGF beta do not have immunosuppressive roles in the development of experimentally induced allergic conjunctivitis. Rather, they augment the infiltration of eosinophils into the conjunctiva during the effector phase of experimentally induced allergic conjunctivitis.

Specific immunodiagnosis of hepatoma by tube leukocyte adherence inhibition assay and a modified method of repeated tube leukocyte adherence inhibition assay.

Tube leukocyte adherence inhibition (LAI) assays were performed with normal liver extract as nonspecific antigen and with hepatoma extract as specific antigen in patients with hepatoma. Titration experiments revealed that the optimal extract concentration was 400 micrograms/ml when expressing the results in terms of a nonadherence index. The results of tube LAI assays were positive in 26 of 40 cases (65%) of hepatoma. The results were negative in all cases of other liver diseases and other cancers. The tube LAI assay was repeated after discarding the non-adherent cells in the initial tube LAI assay with normal liver extract. The nonadherence index of the repeated tube LAI assay we devised was significantly higher than that of the original tube LAI assay (p less than 0.001) in patients with hepatoma. Ten of 12 patients with hepatoma in whom the results of the original tube LAI assay were negative showed positive results in the repeated tube LAI assay. The present study suggests that the problem of false-negative results in tube LAI assay can be solved by repeating the tube LAI assay.

Changes of lysosomal proteinase activities and their expression in rat cultured keratinocytes during differentiation.

The cathepsins B, H and L, lysosomal cysteine proteinases, play a major role in intracellular protein degradation. These proteinase activities and expressions were examined in a Ca2+ regulated epidermal culture system which consists of two morphological cell types: undifferentiated cells grown in low Ca2+ (0.1 mM concentration) and differentiated cells grown in high Ca2+ (1.8 mM concentration), respectively. Cathepsin B and L activities of the differentiated cells showed a several-fold increase compared to that of the undifferentiated cells. In addition, by using CM-cellulose column chromatography, cathepsin B and L were separated and the level of cathepsin L activity increased significantly. Cathepsin B, L and H were also detected by using an immunoblotting procedure in which their bands were expressed after differentiation was induced by the increasing calcium concentration. Cathepsin L activity and immunostaining intensity reached a maximum at 1 or 2 days of differentiation. In contrast, cystatin alpha (an endogenous inhibitor of cysteine-dependent cathepsins) appeared in the final stage of differentiation. These results indicate that the expression of epidermal cathepsins and their endogenous inhibitor are involved in part of the program of cell differentiation and the terminal differentiation process in cultured rat keratinocytes.

Tyrosinase induction and inactivation in normal cultured human melanocytes by endothelin-1.

Since endothelin was found to be expressed in epithelial cells as well as in vascular endothelial cells, the functional regulation of melanocytes with endothelin has been actively investigated. In particular, it has been suggested that endothelin may influence pigmentation and depigmentation, which are mediated by melanocytes. In the present study, we investigated the regulation of melanocyte function and tyrosinase expression by endothelin from the point of view of tyrosinase protein expression and enzyme activity. The influence of endothelins on melanocyte function was assessed. Melanocytes showed a dose-dependent increase in cell proliferation with the addition of endothelin-1. When the confluence of melanocytes was cultured with endothelin-1 for 72 h, tyrosinase activity in melanocytes was significantly and dose-dependently decreased. In contrast, there was no significant change with endothelin-3. However, tyrosinase protein expression of melanocytes was significantly and dose-dependently increased by endothelin-1, but endothelin-3 had no effect. Both the suppression of enzyme activity and the enhanced protein expression were regulated by the ETA receptor antagonist, BQ123. In view of these observations, we conclude that endothelin-1-induced tyrosinase is mediated by ETA receptors. However, the reason for the decrease in the specific activity of tyrosinase remains unknown, and our results suggest that another mechanism underlying the activation of tyrosinase is present in addition to the inductive action of endothelin-1 on tyrosinase.

Lysophosphatidic acid-induced activation of protein Ser/Thr kinases in cultured rat 3Y1 fibroblasts. Possible involvement in rho p21-mediated signalling.

Renaturation kinase assay was used to detect protein kinases activated by lysophosphatidic acid (LPA) in cultured rat 3Y1 fibroblasts. LPA activated several Ser/Thr protein kinases with apparent molecular weights of 145K, 85K, 64-65K (a doublet), and 60K (each named p145, p85, p64165 and p60, respectively) in addition to p43 mitogen activated protein (MAP)-kinase. Experiments using pertussis toxin and botulinum C3 exoenzyme showed that p145, p85, and p64165 kinases were activated by a pertussis toxin-insensitive rho p21-dependent pathway and that the activation of MAP-kinase was mediated by both the pertussis toxin-sensitive rho p21-independent and the pertussis toxin-insensitive rho p21-dependent pathways.

Lysophosphatidic acid induces tyrosine phosphorylation and activation of MAP-kinase and focal adhesion kinase in cultured Swiss 3T3 cells.

Lysophosphatidic acid (LPA) added to serum-starved Swiss 3T3 cells induced, in a time- and concentration-dependent manner, tyrosine phosphorylation of multiple proteins, including proteins of 43, 64, 88 kDa and a group of proteins between 110 and 130 kDa. Among them, two proteins, p43 and p120, were identified as mitogen-activated protein kinase (MAP-kinase) and focal adhesion kinase (FAK), respectively, by immunoprecipitation and immunoblot analysis. Tyrosine phosphorylation of p64 peaked at 1 min and declined rapidly, whereas that of MAP-kinase and FAK peaked at 5 and 10 min after the addition of LPA, respectively. The activity of MAP-kinase determined as phosphorylation of myelin basic protein increased transiently about 3-fold at 5 min, and correlated with tyrosine phosphorylation. These results indicate that tyrosine phosphorylation of these proteins is a part of the signal transduction by LPA and may be involved in its mitogenic responses.

New micro-glass-tube leukocyte adherence inhibition assay assessing cell adherence of mononuclear cell subpopulations defined by monoclonal antibodies.

A new micro-glass-tube leukocyte adherence inhibition (LAI) assay which is appropriate for detecting delayed type hypersensitivity in vitro has been developed for human leukocytes. Enumeration of adherent cells is replaced by a cellular radioimmunoassay determining antibody binding of the monoclonal reagents, OKT4, OKT8 and OKM1, to glass-adherent cells, fixed by glutaraldehyde or formaldehyde. An LAI reactivity to purified protein derivative of tuberculin (PPD) was detectable in donors giving a positive PPD skin test with OKT4 reagent, but not with the other two reagents.