Diversity and composition of flower-visiting insects and related factors in three fruit tree species

Animal-mediated pollination is an essential ecosystem service for the production of many fruit trees. To reveal the community composition of flower-visiting wild insects which potentially contribute to fruit production and to examine the effects of geographic location, local meteorological conditions and locally introduced domesticated pollinators on them, we investigated the community composition of insects visiting the flowers (hereafter, "visitors") of apple, Japanese pear and Oriental persimmon for 1‒3 years at 20 sites around Japan. While most of the variation (82%) of the community composition was explained by tree species with a slight contribution by geographic distance (2%), maximum temperature and tree species contributed 62% and 41% of the variation in total abundance of the visitors, respectively. Though the dominant families of the visitors varied spatiotemporally, the community composition of the visitors of apple and Japanese pear clearly differed from that of Oriental persimmon. While Andrenidae and Syrphidae together accounted for 46%‒64% of the visitors of apple and Japanese pear, Apidae represented 57% of the visitors of Oriental persimmon. The taxonomic richness, diversity and evenness of the visitors were best predicted by locally introduced domesticated pollinators and local meteorological conditions of wind speed and maximum temperature. Amongst these selected factors, locally introduced domesticated pollinators could have the largest impact. It seemed to be strongly related to the reduction of taxonomic richness, diversity and evenness of the visitors, accounting for 41‒89% of the variation. Results suggested that the community composition and total abundance of potential pollinators were predominantly determined by tree species and temperature, but locally introduced domesticated pollinators could have a determinantal pressure on the taxonomic diversity of the community.

First report of pear chlorotic leaf spot-associated virus on Japanese and European pears in Japan and its detection from an eriophyid mite

In May 2018, three leaf samples were collected from Japanese pear trees cv. "Hosui" that exhibited typical chlorotic spot symptoms (Supplementary Figure S1) in a germplasm nursery in Tsukuba, Ibaraki. Total RNA was prepared using the rapid CTAB method (Gambino et al. 2008) for high-throughput sequencing, as described by Kubota et al. (2020). In brief, after removing ribosomal RNAs, a library was constructed by fragmenting RNA, synthesizing cDNA, and polymerase chain reaction (PCR) amplification. Sequencing was performed using NovaSeq 6000 sequencer (Illumina, San Diego, CA, U.S.A.) with paired-end 150 nt reads. De novo assembly was performed using CLC Genomics Workbench 11.0 Software (Qiagen, Hilden, Germany), with a minimum length of 500 bp. A total of 36,017 contigs derived from 33,565,182 reads were obtained and subjected to BLASTX search against the GenBank sequence database as of January 2019. Viruses commonly found in stone fruits, i.e., apple stem pitting virus, apple green crinkle-associated virus, apricot latent virus (foveaviruses), and apple stem grooving virus (a capillovirus), were detected. In addition, five contigs with amino acid sequence homologies to P1-P4 of known emaraviruses and the P7 of High Plains wheat mosaic virus (Tatineni et al. 2014) were detected and designated as PEV-Jp. The complete nucleotide (nt) sequences of the five segments of PEV-Jp were determined by Sanger sequencing of cloned reverse transcription (RT)-PCR amplification products using the primers shown in Supplementary Table S1; the 5'- and 3'-terminal sequences were RACE verified (Takara Bio, Shiga, Japan). In pairwise comparisons, the complete RNA1 to RNA5 of PEV-Jp (LC554756-760) shared 90.7% to 98.7% nt identities with those of PCLSaV-CG1 (MK602177-181), indicating that PEV-Jp is an isolate of PCLSaV. Using newly designed segment-specific primers (Supplementary Table S1), 12 symptomatic Japanese pear trees cv. "Kosui" sampled in 2020 from the same nursery tested positive for PCLSaV by RT-PCR while 12 symptomless trees were negative for the virus. Similar chlorotic spots, sometimes accompany necrotic spots, were observed on European pear (Pyrus communis) cv. "Le Lectier." (Fig. S1F) in Niigata in 2019; PCLSaV was detected by RT-PCR in leaf tissue samples from symptomatic trees (n = 3/3) but not in symptomless trees (n = 0/2). No vector for PCLSaV has been identified (Liu et al. 2020) but acaricide sprays in the early spring are effective for preventing occurrence of chlorotic spots in pear orchards (Nakai et al. 2018). Since the infestations of Eriophyes chibaensis Kadono, an eriophyid mite often observed on the Japanese pear (Fig. S1G to S1I) (Kadono, 1981), has been associated with occurrences of the chlorotic spots (Shimizu et al. 2019), samples of E. chibaensis individuals were collected from PCLSaV-positive Japanese pear cvs. "Akizuki" and "Kosui"and P. communis cv. "Le Lectier." for total nucleic acid isolations via phenol-chloroform extraction, followed by quantitative RT-PCR (Supplementary Table S1). The expected RNA1 and RNA5 specific 150 bp products were detected from mite samples collected from Akizuki (n = 6/12), Kosui (n = 13/18), and Le Lectier (n = 6/8). The results indicate that E. chibaensis can ingest PCLSaV and may be a potential vector for the virus, although additional experiments are needed to demonstrate its vector competency. To our knowledge, this is the first report of PCLSaV in Japan and the first report of its detection in E. chibaensis.

Molecular prevalence of multiple genetic disorders in Border collies in Japan and recommendations for genetic counselling

Reproductive management is necessary to prevent deleterious genetic disorders in purebred dogs, but comprehensive studies aimed at prevention of multiple underlying genetic disorders in a single breed have not been performed. The aims of this study were to examine mutant allele frequencies associated with multiple genetic disorders, using Border collies as a representative breed, and to make recommendations for prevention of the disorders. Genotyping of known mutations associated with seven recessive genetic disorders was performed using PCR assays. More than half (56%) of the Border collies had no mutant alleles associated with any of the seven disorders, suggesting that these disorders can be removed from the population over several generations. Since frequencies of each mutant allele differed among disorders, reproductive management should be performed after the establishment of prevention schemes that are appropriate for each disorder, the type and specificity of genetic test available, and the effective population size in each breeding colony.

The atomic and electronic structures of NiO(001)∕Au(001) interfaces

The atomic and electronic structures of NiO(001)∕Au(001) interfaces were analyzed by high-resolution medium energy ion scattering (MEIS) and photoelectron spectroscopy using synchrotron-radiation-light. The MEIS analysis clearly showed that O atoms were located above Au atoms at the interface and the inter-planar distance of NiO(001)∕Au(001) was derived to be 2.30 ± 0.05 Å, which was consistent with the calculations based on the density functional theory (DFT). We measured the valence band spectra and found metallic features for the NiO thickness up to 3 monolayer (ML). Relevant to the metallic features, electron energy loss analysis revealed that the bandgap for NiO(001)∕Au(001) reduced with decreasing the NiO thickness from 10 down to 5 ML. We also observed Au 4f lines consisting of surface, bulk, and interface components and found a significant electronic charge transfer from Au(001) to NiO(001). The present DFT calculations demonstrated the presence of an image charge beneath Ni atoms at the interface just like alkali-halide∕metal interface, which may be a key issue to explain the core level shift and band structure.

Tight-Binding Study of the {211} Σ=3 Grain Boundary in Cubic Silicon-Carbide

In grain boundaries in compound semiconductors such as SiC, the interface stoichiometry and the wrong bonds between like atoms are of much importance. Firstly, a general definition of the interface stoichiometry in such grain boundaries has been discussed. Secondly, the atomic and electronic structures of the {211} Σ=3 boundary in SiC have been examined by using the self-consistent tight-binding method, based on the atomic models with bonding networks similar to those in the models of the same boundary in Si or Ge. The wrong bonds have significant effects through the large electrostatic repulsion and the generation of localized states as well as those in the {122} Σ=9 boundary in SiC. And the different bond lengths of the wrong bonds very much affect the local bond distortions at the interfaces, which determines the relative stability among the present models.

Energies and Atomic Structures of Grain Boundaries in Diamond: Comparison With Grain Boundaries in Silicon

Fairly different features of grain boundaries in diamond from those in Si were experimentally observed in diamond thin films. As the first step in order to understand the fundamental properties of grain boundaries in diamond, the energy and atomic structure of the {122} σ=9 tilt boundary have been calculated for the first time by using the tight-binding electronic theory. The results have been compared with the calculations of the same boundary and the {111} σ=3 boundary in Si. It has been shown that the σ=9 boundary in diamond has a very large interfacial energy caused by the large bond rigidity as compared with the boundaries in Si and the {111}σ=3 boundary in diamond. This point should be related to the observation that the {122}σ =9 boundary is rarely found in diamond thin films.

Energies and Atomic Structures of Grain Boundaries in Silicon: Comparison Between Tilt and Twist Boundaries

The energies and atomic structures of tilt and twist boundaries in Si have been examined by using the tight-binding electronic theory, and the reason why twist boundaries are seldom found in polycrystalline Si has been investigated. About the frequently observed {122} Σ=9 and {255} Σ=27 tilt boundaries, the configurations without any coordination defects consistent with the electron microscopy observations have relatively small interfacial energies with small bond distortions. About the <111> Σ=7, <011> Σ=3 and <001> Σ = 5 twist boundaries, the configurations contain larger bond distortions or more coordination defects, and much larger interfacial energies than those of the tilt boundaries. The <001> twist boundaries have very complex structures as compared with the other twist boundaries, which can be explained by the morphology of the ideal surfaces. The stability of the tilt boundaries in Si can be explained by the viewpoint of the stable structural units consisting of atomic rings.

Mean Inner Potential of Nanostructured Noble Metal Catalysts - Pt/TiO2 Catalyst -

Catalytic properties of noble metal catalysts are often caused by their nanostructures. Gold catalysts are typical cases. It is especially interesting that the catalytic property of gold suddenly changes to resemble that of platinum when the mean size of gold dispersed on certain oxides is <2nm. This phenomenon should be owing to the change of the local electronic structure of the gold particle or the interface between the gold and the oxides, however its detail has not been cleared yet. We measured the mean inner potential of gold particles supported on TiO2 using electron holography and HREM, and found that the mean inner potential of gold depend largely on the size of the gold particles. When the size is >5nm, the mean inner potential is the same as the reported values of bulk gold (experimental: 21–23V, calculated: 25–30V). When the size is <5nm, it begins to increase >30V, and it begins to increase suddenly >40V at the size <2nm. It indicates that the electronic structure of the gold particle varies from that of the bulk state as the size of the gold reduces due to the nano-size effect or the interaction at the interface, since the mean inner potential is sensitive to the electronic state of the outer valence electron. On the other hand, the behavior of the platinum catalysts is different from that of gold catalysts. When the size of the platinum particle on the TiO2 support is >1.5nm, the mean inner potential of platinum is the same as that of the bulk (∼25V). In case of the particle with the size <1.5nm, it begins to increase and the increase rate is lower than that of the gold particles with the size <2nm. It is suggested to be due to the difference of the interaction with TiO2.

Ocular blood flow changes after dynamic exercise in humans

PURPOSE

To investigate control mechanisms for ocular blood flow changes after dynamic exercise using two different methods.

METHODS

Changes over time in the tissue blood flow in the retina and choroid-retina of healthy volunteers were determined after dynamic exercise (Master's double two-step test), using scanning laser Doppler flowmetry (SLDF) and laser speckle flowgraphy (LSFG). Changes in intraocular pressure (IOP), blood pressure, plasma CO(2) gas concentration (pCO(2)), and levels of nitric oxide (NO) metabolites were examined.

RESULTS

Retinal blood flow measured by SLDF increased significantly only at 15 min after exercise. In contrast, normalized blur (NB) values in the choroid-retina, obtained by LSFG, increased significantly up to 60 min after exercise. Ocular perfusion pressure (OPP), calculated from IOP and blood pressure, increased significantly immediately and 15 min after exercise. The plasma NO metabolite levels increased significantly, although pCO(2) levels were unchanged.

CONCLUSIONS

Dynamic exercise changes OPP and produces increased tissue blood flow in the retina in the immediate postexercise period, while blood flow increases more persistently in the choroid-retina. Difference in control of blood flow in these two regions may be related to stronger autoregulatory mechanism of blood flow in the retina. Nitric oxide may play a role in the regulation of blood flow.

IL-4-mediated development of TGF-beta1-producing cells from naïve CD4(+) T cells through a STAT6-independent mechanism

Transforming growth factor-beta1 (TGF-beta1) is an inhibitory cytokine increasingly recognized as a key factor for immuno-regulation. The function of IL-4 in the regulation of TGF-beta1 production from T cells has been reported previously; however, the precise molecular mechanism still remains to be elucidated. For a better understanding of the mechanism involved in regulation, we have investigated a relationship between the STAT6-dependent pathway and TGF-beta1 production from naïve T cells. TCR crosslinking initiates TGF-beta1 production in CD4(+) T cells, and IL-4-mediated signaling enhances the TGF-beta1 production from naïve CD4(+) T cells. The IL-4-mediated up-regulation of TGF-beta1 production from naïve CD4(+) T cells is elicited in STAT6-deficient (STAT6 KO) mice, but not in IL-4 receptor-deficient (IL-4R KO) mice. These results clearly demonstrate that a STAT6-independent pathway is working in IL-4-mediated enhancement of TGF-beta1 production from naïve CD4(+) T cells. Moreover, the addition of IL-4 showed no additive effect on TGF-beta1 promoter-mediated transcription stimulated by TCR. Therefore, we hypothesize that the IL-4-mediated signaling does not work directly on the transcription of the TGF-beta1 gene, but rather regulates the expansion of TGF-beta1-secreting T cells.

Tumor formation suppressed in gammadeltaT knock-out mice

Tumor formation was examined in mice in which the beta-chain gene of alphabetaT was knocked out (alphabetaT-KO mice) or the delta-chain gene of gammadeltaT was knocked out (gammadeltaT-KO mice). Development of Hepa 1-6 cell hepatoma was observed in six of six alphabetaT-KO mice, in four of six wild-type mice, and in only one of six gammadeltaT-KO mice. These results imply that gammadeltaT cells play a role in suppression of killer cell activity in tumor-bearing mice.

Cytolytic and IFN-gamma-producing activities of gamma delta T cells in the mouse intestinal epithelium are T cell receptor-beta-chain dependent

We analyzed the cytolytic activity of intraepithelial T cells (IEL) isolated from the small intestines of 2- to 3-month-old mutant mice rendered deficient in different gene(s) in which the number of IEL expressing either T cell receptor (TCR)-alpha beta (alpha beta-IEL) or TCR-gamma delta (gamma delta-IEL) were absent or markedly diminished. When compared with wild-type littermates, cytolytic activity of gamma delta-IEL was sharply attenuated in TCR-beta mutant mice but remained unaltered in TCR-alpha mutant mice in which a minor population of dull TCR-beta+ (betadim)-IEL was also present. Cytolytic activity of gamma delta-IEL was maintained in mice doubly homozygous for beta2-microglobulin and transporter associated with antigen processing 1 gene mutations in which a conspicuous decrease was noted in absolute numbers of alpha beta-IEL. In contrast, both TCR-delta and IL-7 receptor-alpha gene mutations that lead to lack of gamma delta-IEL generation did not affect the development or cytolytic activity of the remaining alpha beta-IEL. The anti-CD3 and anti-TCR-gamma delta mAb-induced IFN-gamma production of gamma delta-IEL showed the same TCR-alpha and TCR-beta mutation-dependent variability. These results indicate that cytolytic and IFN-gamma-producing activities of gamma delta T cells in mouse intestinal epithelium are TCR-beta-chain-dependent.

Transport kinetics of leucine enkephalin across Caco-2 monolayers: quantitative analysis for contribution of enzymatic and transport barrier

In this study, we determined the activities of four aminopeptidases such as aminopeptidase B (APB), M (APM), N (APN) and dipeptidylpeptidase IV (DPP IV) in Caco-2 cells and compared with those in the rat intestinal mucosae. The activities of APB, APM and APN appeared to be highest in rat small intestinal mucosa, while DPP IV activity was much higher in Caco-2 cells than that in the rat intestinal mucosa. Next the inhibitory effects of various protease inhibitors were examined in Caco-2 homogenate. Three tested inhibitors, bacitracin, amastatin and puromycin, effectively inhibited the activities of APM, APN and DPP IV except for APB. Further, we quantitatively evaluated the permeation and degradation properties of leucine enkephalin (Leu-Enk) in the presence or absence of inhibitors in Caco-2 monolayer system. Leu-Enk had a high degradation clearance (CLd) and a low permeation clearance (CLp) in Caco-2 monolayers. This finding indicates that the very rapid degradation of Leu-Enk on the apical side of Caco-2 monolayers was due to aminopeptidases. However, these protease inhibitors besides sodium glycocholate were able to reduce the CLd values markedly, thereby increasing the permeation amount of Leu-Enk across Caco-2 monolayers. In particular, amastatin significantly decreased the CLd value and increased the CLp value. This enhanced CLp value was further increased by the coadministration with an absorption enhancer, EDTA or laurylmaltoside. These findings are relevant to the oral administration of peptide drugs and to developing an efficient oral delivery system.

Direct activation of human CD8+ cytotoxic T lymphocytes by interleukin-18

Direct activation of human cytotoxic T lymphocytes (CTL) by interleukin (IL)-18 was observed in a system in which CTL effective against autologous tumor cells were generated. Peripheral blood mononuclear cells (PBMC) from tumor-bearing patients, after removal of natural killer (NK) cells, were cultured in a medium containing IL-1, -2, -4, and -6, with or without IL-18, and stimulated with autologous tumor cells. IL-18 increased the activity of the CTL and the proportion of autologous CD8+ T cells present after 28 days in the induction culture. When purified CD8+ T cells were cultured in the presence of IL-18 and IL-2 for 7 days, the CTL showed enhanced cytotoxic activity against autologous tumor cells. Moreover, a purified CD8+ T cell population, which did not exhibit any apparent cytotoxic activity against autologous tumor cells, displayed cytotoxic activity after 7-day incubation with IL-18. These results suggest that IL-18 may be useful to generate autologous CTL in humans and may thereby contribute to adoptive immunotherapy for tumors.

Enhancement of antigen-specific IFN-gamma production from CD8(+) T cells by a single amino acid-substituted peptide derived from bovine alphas1-casein

Modulation of CD8(+) T-cell responses specific for an exogenous antigen by epitope variants would be advantageous to develop a novel means of antigen-specific immune regulation. We have analyzed CD8(+) T-cell responses to single amino acid-substituted variants of a peptide corresponding to residues 142-149 (p142-149; LAYFYPEL) of alphas1-casein, a major milk allergen, which is a dominant determinant restricted by H-2Kb. An analog peptide L142I with a substitution of Ile for Leu at the nonanchor N-terminal residue induced more IFN-gamma secretion than p142-149 from specific CD8(+) T cells. Furthermore, L142I could prime CD8(+) T cells more efficiently in vivo, and these L142I-primed cells secreted more IFN-gamma than p142-149-primed CD8(+) T cells upon stimulation with p142-149 in vitro. These findings are mainly explained by the greater ability of L142I to form stable Kb-peptide complexes. These findings indicate that appropriate analog peptides may be useful as efficient inducers of CD8(+) T cells which recognize the parent peptide and secrete IFN-gamma, a potent inhibitor of Th2-dependent events, including IgE production.

Selective induction of CD8+ T cell functions by single substituted analogs of an antigenic peptide: distinct signals for IL-10 production

The CD8+ T cell clone 5F1 produces interleukin 10 (IL-10) and interferon gamma(IFN-gamma) in response to stimulation with a peptide corresponding to region 142-149 of bovine alpha(s1)-casein (p142-149). Ninety analog peptides derived from p142-149 with single amino acid substitutions of putative T cell receptor contact residues were prepared to examine whether production of IL-10 and IFN-gamma by 5F1 can be altered by stimulation with these peptides. We found that some peptides triggered only IL-10 production whereas others induced production of IFN-gamma alone or both of these cytokines. Peptides inducing IFN-gamma production triggered both cytotoxicity and a proliferative response, whereas peptides inducing production of IL-10 but not IFN-gamma triggered neither of these responses. Our results clearly demonstrate that the signaling pathway required for IL-10 production in CD8+ T cells differs from that required for IFN-gamma production. The distinct cellular signals for IL-10 production appear to be independent of those for cytotoxicity and the proliferative response of CD8+ T cells.

Oral administration of antigen does not influence the proliferation and IFN-γ production of responsive CD8+ T cells but enables to establish T cell clones with different lymphokine production profile

Feeding of a whole casein diet, which abolished the α(s1)-casein-specific proliferation and IFN-γ productivity of CD(4+) T cells, did not affect the proliferative response of CD8(+) T cells with regard to the antigen dose response, cell dose response, kinetics of the proliferation and epitope specificity, as well as IFN-γ production. To assess the characteristics of the CD8(+) T cells, we established α(s1)-casein-specific CD8(+) T cell clones from both casein-fed and control mice. The established clones produced different amount of IFN-γ and IL-10, and one clone derived from the casein-fed mice produced a remarkable amount of IL-10. The clones from casein-fed mice produced considerable amounts of TGF-β, while those from control mice produced only small amounts. The possible role of CD8(+) T cells in oral tolerance is discussed.

[Simultaneous operation of emergency coronary artery bypass grafting and gastrotomy with suturing ulcer]

A 62-year-old man with complaints of severe chest pain came to our hospital. An emergency coronary angiography was performed and he was diagnosed as having acute myocardial infarction. Due to severe triple vessels disease he was referred to the department of Cardiovascular Surgery to undergo emergency coronary artery bypass grafting. In the coronary care unit, sudden hematoemesis due to hemorrhagic gastric ulcer occurred, however, just when he was going to be transferred to the operation room. Because the gastric bleeding was thought to be serious under extracorporeal circulation, which was indispensable for coronary artery bypass grafting, gastrotomy with suturing ulcer was performed prior to median sternotomy with use of intraaortic balloon pumping. Severe infection was not complicated. His postoperative course was uneventful.

[Short-term results of leaving elephant trunk in type A aortic dissection]

Elephant trunk prosthesis was devised for treatment of multiple aortic aneurysm. But it has applied to type A aortic dissection. Because residual false lumen often dilates gradually and come to have the risk of rupture. Two patients who were diagnosed as type A aortic dissection were performed total aortic arch replacement with Elephant trunk prosthesis on distal anastmosis. Postoperative diagnostic images showed that residual false lumen of proximal descending aorta were thrombosed. Now it is not necessary to perform next extensive aortic replacement. Complication which is threatened in using Elephant trunk prosthesis, paraplegia, thromboembolism, kinking of prosthesis could have been avoided by setting suitable length and diameter of the prosthesis.

[A case of left atrial thrombi following mitral valvuloplasty for mitral regurgitation associated with idiopathic thrombocytopenic purpura]

A 58-year-old man, who had been submitted to an indication of mitral valvuloplasty (MVP) because of severe mitral regurgitation, was diagnosed as idiopathic thrombocytopenic purpura (ITP). In order to diminish the peri-operative blood loss, splenectomy and high-dose bolus administration of gamma-globulin (400 mg/kg/day) were performed at the time of two weeks and during last five days respectively, prior to MVP surgery. In early post-operative stage, anticoagulant therapy was held down considering ITP, and we were not troubled with bleeding throughout the peri-operative period. On the fourteenth post-operative day, however, mural thrombi in the left atrium were pointed out by transesophageal echocardiography (TEE). Then anticoagulant therapy was reinforced by increasing the warfarin dose. When TEE was restudied on 36th, post-operative day, mural thrombi had almost disappeared. Although it is commonly known that mitral valvuloplasty has low risk of thrombosis and less necessity of anticoagulation, hyper coagulability may be feasible in the early post-operative period of our case whose ITP is meticulously treated prior to surgery. Suitable anticoagulation should have been performed regardless of ITP immediately after MVP.

Enhancing effect of interleukin-4 on the secretion of interferon-gamma by alpha s1-casein-specific CD8+ T cells

alpha s1-Casein-specific CD8+ T cell clones expressed the interleukin (IL)-4 receptor, although they did not secrete detectable IL-4. We found that IL-4 significantly enhanced the secretion of interferon (IFN)-gamma by these CD8+ T cell clones. IL-4 also enhanced the secretion of IFN-gamma induced by stimulating the immobilized anti-CD3 antibodies of polyclonal CD8+ T cells which had been isolated from lymph nodes and were stimulated in vitro with the immobilized anti-CD3 antibody and IL-2. In addition, IL-4 added at the time of this first in vitro stimulation induced strong IFN-gamma productivity, as well as IL-4 and IL-10 productivity, which were detectable upon restimulation of these cells. Results are discussed in relation to the inhibitory effects of IFN-gamma production on IL-4-producing cells.

Analysis of cytokine producing activity of intestinal intraepithelial T cells from TCR beta-chain and delta-chain mutant mice

Intestinal intraepithelial T cells (IELs) expressing either gammadelta TCR or alphabeta TCR have been proposed to play an important role in the regulation of intestinal epithelia by producing cytokines that directly influence the adjoining intestinal epithelial cell (IEC) functions. To illuminate this issue, we utilized TCR mutant mice to obtain gammadelta IELs, alphabeta IELs and mixed gammadelta and alphabeta IELs from corresponding alphabeta T-cell-deficient (beta-/-), gammadelta T-cell-deficient (delta-/-) and wild-type (WT) littermate mice. The production of IFN-gamma by these IELs as well as the mRNA for IFN-gamma, TGF-alpha, TGF-beta1, TNF-alpha and TNF-beta in these IELs, in conjunction with the effect of produced cytokines on the expression of class II MHC molecules by the in vitro cell line IEC-6, were investigated. IFN-gamma and TNF-alpha [corrected] specific mRNA were detectable in all freshly isolated gammadelta, alphabeta and WT IELs. In addition to the IFN-gamma and TNF-alpha [corrected] mRNA, alphabeta and WT IELs that had been activated in culture plates coated with anti-CD3 mAb contained mRNA for TGF-beta1 and TNF-beta proteins. In the cultured gammadelta IELs, however, the signals for IFN-gamma and TNF-alpha [corrected] transcripts were weak, and mRNA for the latter two cytokines was almost undetectable. Supernatants from in vitro culturing of alphabeta and WT IELs but not gammadelta IELs induced class II MHC gene expression in IEC-6, whereas, in the presence of anti-IFN-gamma mAb, the same culture supernatants failed to do so. In fact, the concentration of IFN-gamma in supernatants from alphabeta and WT IEL cultures was ten- to twentyfold higher than that in the supernatant from the gammadelta IEL culture. Finally, TGF-alpha specific mRNA was not detectable in the gammadelta and alphabeta IELs even after in vitro activation. These results indicate that alphabeta IELs are superior to gammadelta IELs in the ability to produce IFN-gamma, TGF-beta1, TNF-alpha [corrected] and TNF-beta through TCR crosslinking primary in vitro stimulation.

Difference in signal transduction for IL-10 and IFN-gamma production in a CD8+ T cell clone

CD8+ T cell clones produced both interleukin 10 (IL-10) and interferon-gamma (IFN-gamma) when these cells were stimulated with a T-cell-specific mitogen, concanavalin A (Con A). One of these CD8+ T cell clones, 13G2, secreted IFN-gamma at similar levels with calcium ionophore, A23187, as well as by Con A, but IL-10 production by A23187 was less than by Con A. On the other hand, N6,O2-dibutyryl cAMP enhanced the production of IL-10 but not IFN-gamma when the low doses of Con A or A23187 coexisted. In a T cell clone, the production of these two cytokines required different signal transductions. These results indicate that a T cell clone can produce diverse cytokines depending on the surrounding condition.

CD8+ T cells specific to the exogenous antigen. Mode of antigen recognition and possible implication in immunosuppression

This study demonstrates and characterizes CD8+ T cells specific to the exogenous Ag, bovine alpha s1-casein. Purified CD8+ T cells from alpha s1-casein-primed lymph node cells proliferated well in response to an alpha s1-casein derivative, trypsin-digested alpha s1-casein. CD8+ T cell repertoire for the exogenous Ag was directly demonstrated in the primary culture condition. The intact alpha s1-casein primed the responding CD8+ T cells in vivo more efficiently than the tryptic alpha s1-casein; however, the in vitro proliferative response by the intact alpha s1-casein was weaker than that of the tryptic alpha s1-casein. CD8+ T cells recognized the exogenous Ag in association with MHC class I molecules as revealed by an Ab-blocking study. The major immunodominant region for the CD8+ T cells was mapped to region 136-151 of alpha s1-casein, and peptide 136-151 primed the responding CD8+ T cells but not any CD4+ T cells. Peptide 136-151 is the CD8+ T cell-specific determinant. Upon antigenic stimulation, the exogenous Ag-specific CD8+ T cells produced a significant level of IFN-gamma, which has immune suppressive activity for IgE synthesis. Our study strongly implies that CD8+ T cells that proliferate and produce IFN-gamma in response to the exogenous Ag would play a vital role in Ag-specific immunosuppression.

CD8+ T cells specific to the exogenous antigen. Mode of antigen recognition and possible implication in immunosuppression

This study demonstrates and characterizes CD8+ T cells specific to the exogenous Ag, bovine alpha s1-casein. Purified CD8+ T cells from alpha s1-casein-primed lymph node cells proliferated well in response to an alpha s1-casein derivative, trypsin-digested alpha s1-casein. CD8+ T cell repertoire for the exogenous Ag was directly demonstrated in the primary culture condition. The intact alpha s1-casein primed the responding CD8+ T cells in vivo more efficiently than the tryptic alpha s1-casein; however, the in vitro proliferative response by the intact alpha s1-casein was weaker than that of the tryptic alpha s1-casein. CD8+ T cells recognized the exogenous Ag in association with MHC class I molecules as revealed by an Ab-blocking study. The major immunodominant region for the CD8+ T cells was mapped to region 136-151 of alpha s1-casein, and peptide 136-151 primed the responding CD8+ T cells but not any CD4+ T cells. Peptide 136-151 is the CD8+ T cell-specific determinant. Upon antigenic stimulation, the exogenous Ag-specific CD8+ T cells produced a significant level of IFN-gamma, which has immune suppressive activity for IgE synthesis. Our study strongly implies that CD8+ T cells that proliferate and produce IFN-gamma in response to the exogenous Ag would play a vital role in Ag-specific immunosuppression.

Autoreactive CD8+ T cell clones producing immune suppressive lymphokines IL-10 and interferon-gamma

Highly purified CD8+ T cells were stimulated repeatedly by syngeneic irradiated spleen cells. From separate cloning experiments, we succeeded in isolating two CD8+ clones, 4B4 and D2, which proliferated in response to autologous antigen-presenting cells (APC) completely in the absence of fetal calf serum. A T cell proliferation assay, using congenic strain of mice, indicates that both autoreactive clones were restricted to self-Db molecules. Our study is the first report of establishing murine autoreactive CD8+ clones restricted to self MHC class I molecules. To assess the immune suppressive activity of each autoreactive clone, we measured the production of IL-10 and interferon-gamma, which have specific immune suppressive activity toward type 1 helper T cell (Th1) proliferation and IgE synthesis, respectively. In response to autologous APC, both D2 and 4B4 produced considerable amounts of interferon-gamma and a low but significant level of IL-10. Each supernatant of D2 and 4B4 significantly suppressed IgE synthesis. These results strongly suggest the existence of CD8+ autoreactive T cells with immune suppressive activity.

Anti-IL-10 antibody enhances the proliferation of CD8+ T cell clones: autoregulatory role of murine IL-10 in CD8+ T cells

All CD8+ T cell clones used in this study secreted IL-10, and their proliferation was inhibited by exogenous IL-10. This study addresses the question of whether IL-10 produced by responding T cell clones would inhibit proliferation of the secreting T cells themselves. Anti-IL-10 antibodies enhanced the proliferative response of the CD8+ T cell clones, the enhancing effect appearing in the late period of proliferation. However, the proliferation of both CD4+ Th1 and Th2 clones was not affected by anti-IL-10 throughout the culture. In addition to that of the cloned T cells, the proliferative response of a primary culture of CD8+ T cells was enhanced by the anti-IL-10 antibody. This is the first report on a lymphokine which has an autoregulatory role in inhibiting T cell proliferation.

Effects of Structural Disorder on the Electronic Properties of Silicon: Tight-Binding Calculations of Grain Boundaries

The atomic and electronic structures of tilt and twist boundaries in Si have been calculated by using the transferable semi-empirical tight-binding (SETB) method, and the relations between the local structural disorder and the electronic properties of Si have been obtained clearly. The odd-membered rings and the four-membered rings induce the changes of the shape of the local density of states (LDOS). The bond distortions generate the peaks at the band edges in the LDOS, and greatly distorted bonds induce the weak-bond states inside the band gap. The three-coordinated defect generates a deep state in the band gap, which is much localized at the three-coordinated atom. The five-coordinated defect generates both deep and shallow states. The deep state is localized in the neighboring atoms except the five-coordinated atom, although the shallow states exist among the five-coordinated atom and the neighboring atoms. Configurations of boundaries are very effective in order to clarify the effects of the local structural disorder in amorphous SI.

Endoscopic laser therapy in the curative and palliative treatment of upper gastrointestinal cancer

Endoscopic laser treatment was initially applied for gastrointestinal bleeding, but has been actively extended, especially in Japan, to the curative treatment of early upper gastrointestinal cancers. We have treated 10 cases of early gastric cancer and 1 case of early esophageal cancer by Nd-YAG laser radiation, and 2 cases of early gastric cancer by photochemical therapy (PCT) with argon laser + hematoporphyrin derivative. Also, 62 cases of advanced cancer were treated, 10 of the esophagus and 52 of the stomach, for bleeding (18 cases) or stenosis (34 cases). The cases were nonresectable or they were patients who refused surgery. Satisfactory results were obtained by treatment with YAG laser, but have not yet been obtained with PCT. In order to find indications for the possible extension of endoscopic laser therapy to operable cases of early gastric cancer, we studied lymph node metastases in 200 cases of early gastric cancer surgically treated by us. It was found that early gastric cancers (both mucosal and submucosal) measuring less than 2 cm in diameter, of type I, IIa, and IIc (without ulcer scar), had no lymph node metastases and such cases can be treated by local therapy--such as endoscopic laser therapy. In palliative endoscopic laser therapy for complications of advanced gastrointestinal cancers, there are no major problems with active performance. We obtained a high (90%) hemostatic rate in bleeding cases of upper gastrointestinal cancer and a satisfactory (65%) rate of dilating effect in cases of cancerous stenosis at the esophagus and cardia.(ABSTRACT TRUNCATED AT 250 WORDS)