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.

Analysis of genetic divergence between closely related lines of chickens.

The aim of the present study was to characterize genetic diversity within and differentiation between 5 closely related lines of Japanese-native chickens, the Nagoya breed, based on microsatellite polymorphisms. For 5 Nagoya lines, the mean number of alleles per locus, the observed heterozygosity, the expected heterozygosity, and the inbreeding coefficient within a line ranged from 2.35 to 2.85, from 0.385 to 0.507 (average = 0.438), from 0.404 to 0.480 (average = 0.433), and from -0.056 to 0.074, respectively. These results indicated that Nagoya lines have moderate levels of genetic diversity and no severe inbreeding signatures. Genetic differentiations between pairs of lines (pairwise F(ST)) ranged from 0.0224 to 0.2500. The lowest differentiation was found between 2 lines that were divided into distinct lines about 10 years ago. Genetic clustering analyses, the neighbor-joining tree constructed from genetic distances of the proportion of shared alleles and the Bayesian model-based clustering, were carried out based on multilocus genotypes of individuals. The results suggested that Nagoya lines were genetically distinct from commercial gene pools (broilers and white- and brown-egg layers) and that the Nagoya breed is a unique genetic resource. The results from the present study have the potential to contribute to future breeding and management of lines of the Nagoya breed.

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.

High-resolution spectroscopy of Lambda16N by electroproduction.

An experimental study of the (16)O(e,e'K(+))(Lambda)(16)N reaction has been performed at Jefferson Lab. A thin film of falling water was used as a target. This permitted a simultaneous measurement of the p(e,e'K(+))Lambda, Sigma(0) exclusive reactions and a precise calibration of the energy scale. A ground-state binding energy of 13.76+/-0.16 MeV was obtained for (Lambda)(16)N with better precision than previous measurements on the mirror hypernucleus (Lambda)(16)O. Precise energies have been determined for peaks arising from a Lambda in s and p orbits coupled to the p(1/2) and p(3/2) hole states of the (15)N core nucleus.

Allergen-specific immunotherapy alters the expression of B and T lymphocyte attenuator, a co-inhibitory molecule, in allergic rhinitis.

BACKGROUND: B7/CD28 family co-signalling molecules play a key role in regulating T cell activation and tolerance. Allergen-specific immunotherapy (SIT) alters allergen-specific T cell responses. However, the effect of SIT on the expression of various co-signalling molecules has not been clarified. OBJECTIVE: We sought to determine whether SIT might affect the expression of three co-inhibitory molecules, programmed death (PD)-1, B7-H1 and B and T lymphocyte attenuator (BTLA), in Japanese cedar pollinosis (JCP). METHODS: Peripheral blood mononuclear cells (PBMCs) were isolated from JCP patients who had or had not received SIT. PBMC were cultured in the presence or absence of Cry j 1, after which the cell surface expression of PD-1, B7-H1 and BTLA, as well as IL-5 production, were determined. In addition, the effect of BTLA cross-linking on IL-5 production was examined. RESULTS: After Cry j 1 stimulation, no significant differences in PD-1 and B7-H1 expression were observed between SIT-treated and SIT-untreated patients. BTLA expression was down-regulated in untreated patients after Cry j 1 stimulation and up-regulated in SIT-treated patients. Up-regulation of BTLA in SIT-treated patients was particularly apparent in a CD4(+) T cell subset. IL-5 production was clearly reduced among SIT-treated patients, and the observed changes in BTLA expression correlated negatively with IL-5 production. Moreover, immobilization of BTLA suppressed IL-5 production in JCP patients. CONCLUSION: These results suggest that both IL-5 production and down-regulation of BTLA in response to allergen are inhibited in SIT-treated patients with JCP. BTLA-mediated co-inhibition of IL-5 production may contribute to the regulation of allergen-specific T cell responses in patients receiving immunotherapy.

High resolution spectroscopy of (lambda)(12)B by electroproduction.

An experiment measuring electroproduction of hypernuclei has been performed in hall A at Jefferson Lab on a 12C target. In order to increase counting rates and provide unambiguous kaon identification two superconducting septum magnets and a ring imaging Cherenkov detector were added to the hall A standard equipment. An unprecedented energy resolution of less than 700 keV FWHM has been achieved. Thus, the observed (Lambda)(12)B spectrum shows for the first time identifiable strength in the core-excited region between the ground-state s-wave Lambda peak and the 11 MeV p-wave Lambda peak.

A method for discriminating a Japanese chicken, the Nagoya breed, using microsatellite markers.

The Nagoya breed native to Japan is popular as a dual-purpose breed for eggs and meat. The current study describes a method to discriminate between the Nagoya breed and other breeds and commercial stocks of chicken. Four strains of the Nagoya breed established at the Aichi-ken Agricultural Research Center were analyzed using 25 microsatellite markers. In these strains, 5 of the markers (ABR0015, ABR0257, ABR0417, ABR0495, and ADL0262) had a single allele. Other chicken samples (448) of various breeds and hybrids were analyzed using the same 5 markers. None of these chicken samples had the same allele combination as the Nagoya breed strains. These 5 microsatellite markers provide a practical method to accurately discriminate the Nagoya breed from other chicken breeds.

Maleylated human serum albumin inhibits HIV-1 infection in vitro.

Maleylated-human serum albumin (Mal-HSA) inhibited human immunodeficiency virus type-1 (HIV-1) infection of MT-4 cells in vitro. It was also found to inhibit the fusion between uninfected CD4+ cells (Molt-4 clone 8 cells) and HIV-1 infected cells (Molt-4/HIV-1) to form syncytia. To investigate the mechanism of the inhibition, a study was designed to determine whether Mal-HSA could bind to CD4+ cells. Mal-HSA could bind to both MT-4 cells and Molt-4 clone 8 cells with high affinity, Kd = 2.0 nM and Kd = 5.8 nM, respectively. However, Mal-HSA could neither inhibit anti CD4 antibody Leu 3a binding to Molt-4 clone 8 cells nor modulate the expression of CD4 molecules on the surface of the cells. Mal-HSA binding to Molt-4 clone 8 cells was completely inhibited by sulfated polysaccharides bearing anti-HIV activity, such as dextran sulfate, fucoidan and carrageenan. Other HIV-1 susceptible human T-cell lines, such as Molt-4, CEM-5, H-9 and HuT-78 cells, also have Mal-HSA binding sites showing a high affinity, Kd = 0.9 +/- 0.4 nM. Mal-HSA binding proteins of Molt-4 clone 8 cells were identified by ligand blotting as 155 and 220 kDa proteins. Unlike dextran sulfate, Mal-HSA could not inhibit reverse transcriptase activity of HIV-1. These results indicate that Mal-HSA inhibits HIV-1 infection and syncytia formation, and suggest that 155 and/or 220 kDa proteins of target cells are involved in HIV-1 adsorption and/or the membrane fusion between HIV-1 and target cells.

Human placental ferritin receptor.

Brush-border membranes from human placenta were prepared and their purity was clarified by biochemical and morphological methods. Ferritin binding to these prepared membranes was examined using horse spleen 125I-apoferritin, and was found to be completed within 10 min at 37 degrees C and pH 7.5. The amount of ferritin bound to the membranes was found to be proportional to the amount of membrane added and saturable for a given amount of the membrane in the presence of excess ligand. The membranes exhibited specific ferritin binding with a Ka of 2.3 X 10(7) M-1 at pH 7.5. A competitive binding assay indicated that horse spleen 125I-apoferritin binding was inhibited by a 10-fold molar excess of horse spleen ferric ferritin and a 500-fold molar excess of human transferrin. These results suggest that human placental brush-border membranes have specific receptors for horse spleen apoferritin molecules.

Non-equivalent cooperation between the two nucleotide-binding folds of P-glycoprotein.

To identify the roles of the two nucleotide-binding folds (NBFs) in the function of human P-glycoprotein, a multidrug transporter, we mutated the key lysine residues to methionines and the cysteine residues to alanines in the Walker A (WA) motifs (the core consensus sequence) in the NBFs. We examined the effects of these mutations on N-ethylmaleimide (NEM) and ATP binding, as well as on the vanadate-induced nucleotide trapping with 8-azido-[alpha-32P]ATP. Mutation of the WA lysine or NEM binding cysteine in either of the NBFs blocked vanadate-induced nucleotide trapping of P-glycoprotein. These results suggest that if one NBF is non-functional, there is no ATP hydrolysis even if the other functional NBF contains a bound nucleotide, further indicating the strong cooperation between the two NBFs of P-glycoprotein. However, we found that the effect of NEM modification at one NBF on ATP binding at the other NBF was not equivalent, suggesting a non-equivalency of the role of the two NBFs in P-glycoprotein function.

Possible cause of G-C-->C-G transversion mutation by guanine oxidation product, imidazolone.

BACKGROUND: The genome is constantly assaulted by oxidation reactions which are likely to be associated with oxygen metabolism, and oxidative lesions are generated by many types of oxidants. Such genotoxin-induced alterations in the genomic message have been implicated in aging and in several pathophysiological processes, particularly those associated with cancer. The guanine base (G) in genomic DNA is highly susceptible to oxidative stress due to having the lowest oxidation potential. Therefore, G-C-->T-A and G-C-->C-G transversion mutations frequently occur under oxidative conditions. One typical lesion of G is 8-oxo-7,8-dihydro-guanine (8-oxoG), which can pair with A. This pairing may cause G-C-->T-A transversion mutations. Although the number of G-C-->C-G transversions is rather high under specific oxidation conditions such as riboflavin photosensitization, the molecular basis of G-C-->C-G transversions is not known. RESULTS: To determine which oxidative products are responsible for G-C-->C-G transversion mutations, we photooxidized 5'-d(AAAAAAGGAAAAAA)/5'-d(TTTTTTCCTTTTTT) using either riboflavin or anthraquinone (AQ) carboxylate under UV irradiation. Prolonged low-temperature (4 degrees C) enzymatic digestion of photoirradiated sample indicated that under both conditions the amount of 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG) initially increased with decreasing amounts of 2'-deoxyguanosine (dG), then decreased with the formation of 2-amino-5-[(2-deoxy-beta-D-erythro-pentofuranosyl)amino]-4H-imidazol-4-one (dIz), suggesting that nascent 8-oxoG was further oxidized to 2,5-diamino-4H-imidazol-4-one (Iz) in duplex DNA. Photoirradiation of an AQ-linked oligomer with a complementary strand containing 8-oxoG indicated that 8-oxoG residues were oxidized to Iz. These results indicate that Iz is formed from 8-oxoG through long-range hole migration. Primer extension experiments using a template containing Iz demonstrated that only dGTP is specifically incorporated opposite Iz suggesting that specific Iz-G base pairs are formed. The 'reverse' approach consisting of DNA polymerization using dIzTP showed that dIzTP is incorporated opposite G, further confirming the formation of a Iz-G base pair. CONCLUSIONS: HPLC product analysis demonstrated that Iz is a key oxidation product of G through 8-oxoG in DNA photosensitized with riboflavin or anthraquinone. Photoreaction of AQ-linked oligomer confirmed that Iz is formed from 8-oxoG through long-range hole migration. Two sets of primer extension experiments demonstrated that Iz can specifically pair with G in vitro. Specific Iz-G base pair formation can explain the G-C-->C-G transversion mutations that appear under oxidative conditions.

Purification, characterization and molecular cloning of Cha o 1, a major allergen of Chamaecyparis obtusa (Japanese cypress) pollen.

Pollen of Chamaecyparis obtusa (Japanese cypress) is one of the causes of allergic pollinosis in Japan. A major allergen of the pollen designated Cha o 1, was purified by two-step ion exchange chromatography. Cha o 1 was separated into four components with molecular masses of 48.5 kDa and 52.0 kDa, each with pIs of 6.77 and 6.82. The 23-residue N-terminal sequence of Cha o 1 was determined and shown to have high identity with that of Cry j 1, a major allergen of Cryptomeria japonica pollen. cDNA coding for Cha o 1 was cloned by hybridization screening using Cry j 1 cDNA as a probe. One of the cDNA clones, pCHA-1 was sequenced and found to code for a putative 21-residue signal peptide and a 354-residue native protein with a derived molecular mass of 38.1 kDa. The deduced amino acid sequence of Cha o 1 showed 79-80% identity with those of Cry j 1. These findings were consistent with observations of a close crossreaction between the two allergens. Homology analyses revealed that Cha o 1 had 46-49% identity with Amb a 1 families and Amb a 2, the major allergens of short ragweed. Cry j 1 has pectate lyase enzyme activity, suggesting that Cha o 1 may have the same enzyme activity as Cry j 1.

Embryonic expression of beta-actin-lacZ hybrid gene injected into the fertilized ovum of the domestic fowl.

An experiment was carried out to investigate the expression of cloned DNA injected into the germinal disc of the chick fertilized ovum. The beta-actin-lacZ hybrid gene, MiwZ, was injected, in the closed circular form, into the cytoplasm of the germinal disc at the single-cell stage. The embryos were cultured in vitro, then in recipient eggshells up to day 4 of incubation. The survival rate of the embryos at day 4 was 42% (55/130), and the rate of embryos expressing MiwZ was 64% (35/55). Twenty-two embryos expressed the MiwZ in both embryonic and extraembryonic tissues, while the remainder expressed the MiwZ in only extraembryonic tissues. Mosaic expression was observed in most of the embryos expressing MiwZ in embryonic tissues. Expression throughout all tissues of the embryo including blood cells occurred in one case. In this case, the injected DNA was assumed to have integrated at an earlier stage. The results indicate that it is now possible to investigate the promoter activities of introduced exogenous genes as well as the effect of introduced genes on embryogenesis in early chick embryos. This technique may also facilitate the production of transgenic chicks.

Morphological characteristics of the temporomandibular joint in the pouch young of the Tasmanian devil.

We recently reported the absence of the articular disc, which is a constant structure in mammals, in the temporomandibular joint of the adult Tasmanian devil. However, whether the articular disc disappears with growth of the animal was unknown. The aim of this study was to determine whether a pouch young of the Tasmanian devil has the articular disc. The temporomandibular joint of a fresh carcass of the pouch young, whose crown-rump length was 43 mm, was examined microscopically and by microcomputed tomography. The absence of the articular disc in the pouch young temporomandibular joint was histologically confirmed. It is suggested that the articular disc of the Tasmanian devil is naturally absent.

Aureobasidin A, an antifungal cyclic depsipeptide antibiotic, is a substrate for both human MDR1 and MDR2/P-glycoproteins.

The human MDR1 gene encodes the multidrug transporter P-glycoprotein (Pgp). Although the MDR2/Pgp shares about 80% identity at the amino acid level with the MDR1/Pgp, the MDR2/Pgp cannot act as a multidrug transporter. We examined the drug sensitivity of Saccharomyces cerevisiae expressing either the human MDR1/Pgp or MDR2/ Pgp. The human MDR1/Pgp conferred about 4-fold resistance to aureobasidin A, a cyclic depsipeptide antifungal antibiotic, on the drug-sensitive yeast strains. Interestingly the human MDR2/Pgp also conferred about 2.5-fold resistance to aureobasidin A. The resistance to aureobasidin A conferred by the MDR2/Pgp as well as by the MDR1/Pgp was overcome by vinblastine, verapamil, and cyclosporin A, depending on their concentrations, but not by colchicine. Aureobasidin A probably interacts directly with Pgps, because it overcame multidrug resistance of human cells and inhibited azidopine photoaffinity labeling of MDR1/Pgp in human cell membranes. These results suggest the possibility that the human MDR1 and MDR2/Pgps have conserved domain(s) for drug recognition.

Ling Zhi-8: studies of a new immunomodulating agent.

Ling Zhi-8 (LZ-8) is a protein derived from the fungus Ganoderma lucidum and has immunomodulatory capacities. It was shown to be mitogenic toward mouse splenocytes in vitro and immunosuppressive in vivo by reducing antigen-induced antibody formation and by preventing completely the incidence of autoimmune diabetes in nonobese diabetic mice. In this study, the mitogenic effects of LZ-8 on human mononuclear cells are reported. In accordance to its mitogenic effect on mouse splenocytes, LZ-8 proved to be mitogenic for human PBMC. This mitogenic effect of LZ-8 apparently required the presence of monocytes. We also demonstrated it to be immunosuppressive in vitro in a human MLC performed in the absence of monocytes, using purified T cells and EBV-transformed allogeneic B cells. Furthermore, we tested LZ-8 for its possible suppressive effects in 2 different models of allogeneic tissue transplantation. LZ-8 proved to have a significant effect on cellular immunity, since its administration in an allografted mouse skin model resulted in an increased survival time. In a model of transplanted allogeneic pancreatic rat islets, LZ-8 was effective in delaying the rejection process of allografted islets. More frequent or continuous administration resulted in a further prolongation of survival time. No serious side effects of LZ-8 could be discerned in these experiments.

Immunohistochemical studies on hemoglobin-haptoglobin and hemoglobin catabolism sites.

In order to clarify the catabolism sites of Hb-Hp and free Hb, the organ distributions of [125I]-Hb-Hp and [125I]-Hb were studied, and the cell types in each organ incorporating them were determined by immunohistochemical methods. After administration of [125I]-Hb-Hp in very small amounts to rats, 84.5% was incorporated into the liver, but the renal uptake was only 0.6%. [125I]-Hb was incorporated into the kidneys rather than into the liver when a fivefold greater amount of [125I]-Hb than the binding capacity of plasma Hp was administered. Parenchymal cells, but not Kupffer cells, in the liver were stained with anti-Hb or anti-Hp IgG after administration of Hb in an amount corresponding to the Hb binding capacity of Hp. The proximal tubule cells, but not the distal tubule cells, in the kidney were stained with anti-Hb IgG after administration of a fivefold greater amount of Hb than the binding capacity of Hp. On the basis of these results, we suggest that Hb-Hp was incorporated mainly into liver parenchymal cells and did not traverse glomeruli in the kidney. In contrast to Hb-Hp, free Hb could pass through the glomeruli easily and was incorporated into the proximal tubule cells.

Out of plane measurements of the decay neutron from the giant resonance in the 12C(e,e(')n)11C reaction

Out of plane measurements of the angular correlations for the 12C(e, e(')n) reaction have been performed for the first time in the giant resonance region. The cross sections were directly separated into the longitudinal and transverse, longitudinal-transverse, and transverse-transverse components. The cross section at the peak of the giant resonance ( omega = 22.5 MeV) has been found to be almost all longitudinal. It was reproduced by the multipole expansion with E0 and E2 components besides E1. The longitudinal-transverse component might have a maximum around 24 MeV. The transverse-transverse component is very small over the giant resonance.

Establishment and characterization of a human colon cancer cell line, OUMS-23, from a patient with familial adenomatous polyposis.

A human colon carcinoma cell line designated OUMS-23 has been established from metastatic pericardial fluid of a male familial adenomatous polyposis patient with colon cancer. Since 1984, the epithelial cells have been maintained in culture. Ultrastructural studies revealed the presence of numerous microvilli on the cell surface and desmosomes between the adjacent cells. The cells secreted carcinoembryonic antigen into the culture medium (15 ng/10(6) cells-1 24 h-1). The cells expressed heat-stable placental-type-like alkaline phosphatase, whereas the normal counterparts expressed tissue-unspecific alkaline phosphatase. Karyotypic analysis showed that the cell line was of human origin and that the chromosome number was broadly distributed between 53 and 118. Southern blot analysis of the APC gene revealed no abnormalities in OUMS-24 cells, while Northern blot analysis demonstrated that the expression of the gene was about one-half that of the normal human fibroblasts. No mutations at the "hot spots" of codons 12 and 61 of H-, K- and N-ras proto-oncogenes were detected in the cells. The cells could grow in soft agar at a cloning efficiency of 6.5%, and upon transplantation into nude mice the cells formed tumors, which were diagnosed as differentiated adenocarcinoma.

Thermophilic biodesulfurization of dibenzothiophene and its derivatives by Mycobacterium phlei WU-F1.

Dibenzothiophene (DBT) derivatives can be detected in diesel oil following hydrodesulfurization treatment, and they are widely recognized as target compounds for more efficient desulfurization. The moderately thermophilic bacterium Mycobacterium phlei WU-F1 was isolated for its ability to grow at 50 degrees C in a medium with DBT as the sole source of sulfur. At 50 degrees C, resting cells of WU-F1 degraded 0.81 mM DBT within only 90 min to produce 2-hydroxybiphenyl as a desulfurized metabolite through the selective cleavage of carbon-sulfur bonds, and also degraded 0.81 mM of derivatives such as 2,8-dimethylDBT, 4,6-dimethylDBT and 3,4-benzoDBT within 8 h. In addition, the resting cells exhibited high DBT-desulfurizing ability over a wide temperature range from 20 to 50 degrees C. Because M. phlei WU-F1 possesses higher desulfurizing ability toward DBT and the derivatives over a wider temperature range than any other microorganisms previously reported, it may have useful practical applications for biodesulfurization.