First Application of Mass Measurements with the Rare-RI Ring Reveals the Solar r-Process Abundance Trend at A=122 and A=123.

The Rare-RI Ring (R3) is a recently commissioned cyclotronlike storage ring mass spectrometer dedicated to mass measurements of exotic nuclei far from stability at Radioactive Isotope Beam Factory (RIBF) in RIKEN. The first application of mass measurement using the R3 mass spectrometer at RIBF is reported. Rare isotopes produced at RIBF-^{127}Sn, ^{126}In, ^{125}Cd, ^{124}Ag, ^{123}Pd-were injected in R3. Masses of ^{126}In, ^{125}Cd, and ^{123}Pd were measured whereby the mass uncertainty of ^{123}Pd was improved. This is the first reported measurement with a new storage ring mass spectrometry technique realized at a heavy-ion cyclotron and employing individual injection of the preidentified rare nuclei. The latter is essential for the future mass measurements of the rarest isotopes produced at RIBF. The impact of the new ^{123}Pd result on the solar r-process abundances in a neutron star merger event is investigated by performing reaction network calculations of 20 trajectories with varying electron fraction Y_{e}. It is found that the neutron capture cross section on ^{123}Pd increases by a factor of 2.2 and ß-delayed neutron emission probability, P_{1 n}, of ^{123}Rh increases by 14%. The neutron capture cross section on ^{122}Pd decreases by a factor of 2.6 leading to pileup of material at A=122, thus reproducing the trend of the solar r-process abundances. The trend of the two-neutron separation energies (S_{2n}) was investigated for the Pd isotopic chain. The new mass measurement with improved uncertainty excludes large changes of the S_{2n} value at N=77. Such large increase of the S_{2n} values before N=82 was proposed as an alternative to the quenching of the N=82 shell gap to reproduce r-process abundances in the mass region of A=112-124.

Interleukin 33 is induced by tumor necrosis factor alpha and interferon gamma in keratinocytes and contributes to allergic contact dermatitis.

BACKGROUND: Interleukin (IL) 33, a novel member of the IL-1 family, is produced mainly by epithelial cells and endothelial cells in response to various types of stress, including necrosis. The effects of IL-33 on the immune cells involved in allergic contact dermatitis have recently been revealed in vitro. However, in vivo, the induction mechanism and function of IL-33 are not fully understood. OBJECTIVES: Our objectives were to investigate induction of IL-33 in keratinocytes and to evaluate the functions of IL-33 and its inducers in a murine model of allergic contact dermatitis. MATERIAL AND METHODS: KERTr cells, a human keratinocyte cell line, were cultured with various cytokines, including tumor necrosis factor (TNF) alpha and interferon (IFN) gamma. IL-33 expression was detected using quantitative reverse transcriptase polymerase chain reaction, immunocytochemistry, and Western blotting. The functions of IL-33, TNF-a, and IFN-y in allergic contact dermatitis were evaluated using a murine model. RESULTS: TNF-alpha and IFN-gamma induced expression of IL-33 mRNA and protein in KERTr cells. Blockade of IL-33 attenuated swelling in the ears of the experimental mice. Similar effects were noted for blockade of TNF-alpha and IFN-gamma in these mice. CONCLUSIONS: TNF-alpha and IFN-gamma induce expression of IL-33, and IL-33 produced by keratinocytes contributes to allergic contact dermatitis. Blockade of IL-33, TNF-alpha, and IFN-gamma could represent novel and potent strategies to treat allergic contact dermatitis.

In situ time-resolved XAFS study on the structural transformation and phase separation of Pt3Sn and PtSn alloy nanoparticles on carbon in the oxidation process.

The dynamic behavior and kinetics of the structural transformation of supported bimetallic nanoparticle catalysts with synergistic functions in the oxidation process are fundamental issues to understand their unique catalytic properties as well as to regulate the catalytic capability of alloy nanoparticles. The phase separation and structural transformation of Pt(3)Sn/C and PtSn/C catalysts during the oxidation process were characterized by in situ time-resolved energy-dispersive XAFS (DXAFS) and quick XAFS (QXAFS) techniques, which are element-selective spectroscopies, at the Pt L(III)-edge and the Sn K-edge. The time-resolved XAFS techniques provided the kinetics of the change in structures and oxidation states of the bimetallic nanoparticles on carbon surfaces. The kinetic parameters and mechanisms for the oxidation of the Pt(3)Sn/C and PtSn/C catalysts were determined by time-resolved XAFS techniques. The oxidation of Pt to PtO in Pt(3)Sn/C proceeded via two successive processes, while the oxidation of Sn to SnO(2) in Pt(3)Sn/C proceeded as a one step process. The rate constant for the fast Pt oxidation, which was completed in 3 s at 573 K, was the same as that for the Sn oxidation, and the following slow Pt oxidation rate was one fifth of that for the first Pt oxidation process. The rate constant and activation energy for the Sn oxidation in PtSn/C were similar to those for the Sn oxidation in Pt(3)Sn/C. In the PtSn/C, however, it was hard for Pt oxidation to PtO to proceed at 573 K, where Pt oxidation was strongly affected by the quantity of Sn in the alloy nanoparticles due to swift segregation of SnO(2) nanoparticles/layers on the Pt nanoparticles. The mechanisms for the phase separation and structure transformation in the Pt(3)Sn/C and PtSn/C catalysts are also discussed on the basis of the structural kinetics of the catalysts themselves determined by the in situ time-resolved DXAFS and QXAFS.

Insulator-metal phase transition of Pr(0.6)Ca(0.4)MnO(3) studied by x-ray absorption spectroscopy in pulsed magnetic fields.

Evolution of the Mn K-edge x-ray absorption near edge structure (XANES) in Pr(0.6)Ca(0.4)MnO(3) at pulsed magnetic fields has been investigated. A small enhancement of XANES spectra is detected across the magnetic-field-induced transition from the charge- and orbital-ordered (COO) insulator to ferromagnetic metal at 20 K. It is found that the magnetic-field dependence of the enhancement shows clear hysteresis, as seen in the magnetization with metamagnetic transition, suggesting a significant correlation between the change in the XANES and the field-induced collapse of the COO state. The enhancement of the absorption can be explained by an increase of the 4p density of states due to a reduction of hybridization between the 4p state of the central Mn ion with the core hole and the neighboring Mn 3d state. Local structural change around Mn ions is expected to modify the strength of the hybridization.

Talbot interferometry for imaging two-dimensional electron density distribution over discharge plasma with higher sensitivity.

The basic properties of a Talbot interferometer implementing pinhole arrays were experimentally and numerically investigated for the improvement of measurement sensitivity of laser wavefront sensors utilized for electron density imaging over discharge plasmas. A numerical simulation using a plane wave decomposition method indicated that the pinhole arrays with a pitch of 300 µm and a pinhole diameter of 150 µm were most suitable for the measurement of the millimetre-scale discharge plasmas, in consideration of the spatial resolution and measurement accuracy. The plane wave decomposition simulation expected that the measurement sensitivity of the 8th-Talbot-length interferometer could be improved by a factor of 4 compared with the previously developed Shack-Hartmann type laser wavefront sensors, which was experimentally verified by the self-image behavior of the pinhole arrays. The Talbot interferometric system was successfully used for electron density imaging over the vacuum arcs generated between a 3-mm gap. The electron density image observed by the Talbot interferometers was in excellent agreement with that visualized by the previously developed Shack-Hartmann sensors. The practical notification for the pinhole array fabrication was also presented.

Four states of tyrosine residues in the fibrinogen molecule.

The ionization of tyrosine residues in fibrinogen was studied by a spectrophotometric method. The total of 100 tyrosine residues in the fibrinogen molecule was classified into four states: (1) 28 tyrosine residues with pK 10.1 (m = 1.0). (2) tyrosine residues with pK 11.5 (m = 1.0), (3) 20 tyrosine residues with pK 12.2 (m = 3.0) and (4) 10 tyrosine residues non-ionizable. When fibrinogen was treated with 4 M guanidine . HCl, all of the tyrosine residues became ionizable with the ionization characteristics of pK 10.1 (m = 1.0). The ionization characteristics of tyrosine residues in plasmin-digested fibrinogen were similar to those of fibrinogen, while in CNBr-treated fibrinogen they were fairly different. The value, m, stands for the number of hydroxyl ions involved in the ionization of a tyrosine residue.

Fibrin membrane endowed with biological function. V. Multienzyme complex of uricase, catalase, allantoinase and allantoicase.

The enzymes (uricase (EC 1.7.3.3), allantoinase (EC 3.5.3.4), and allantoicase (EC 3.5.2.5) which participate in degradation of purine bases, were embedded separately in fibrin membranes formed by fibrinogen-fibrin conversion with thrombin. All of these enzymes together with catalase were also embedded in a single fibrin membrane to make an immobilized multienzyme complex. The multienzyme complex in fibrin membrane thus prepared had an ability of degradation of uric acid to urea and glyoxylic acid via allantoin and allantoic acid. The stability of immobilized uricase or catalase embedded in fibrin membrane upon lyophilization was also tested in a comparison with nonimmobilized enzymes.

Sodium trichloroacetate-induced helical conformation of poly(L-lysine).

Sodium trichloroacetate which has been reported previously to be an effective denaturation reagent for proteins was applied to poly(L-lysine) and poly(L-glutamic acid) to see its effects on a coil-to-helix transition and on the chemical reactivities of the xi-amino group of poly(L-lysine). Addition of sodium trichloroacetate to poly(L-lysine) induced a helical conformation even at neutral pH where the xi-amino group of the polymer was protonated. On the other hand, little effect was observed on the coil-to-helix transition of poly(L-glutamic acid). The xi-amino group of poly(L-lysine) has an anomalously high reactivity with naphthoquinone 4,6-disulfonate carrying a negative charge. Sodium trichloroacetate inhibited the reaction of the xi-amino group with this reagent, while sodium trichloroacetate enhanced slightly the reaction of the xi-amino group of poly(L-lysine) with diazonium-1-H-tetrazole carrying a positive charge.

Photooxidation of fibrinogen in the presence of methylene blue and its effect on polymerization.

Human fibrinogen was illuminated in the presence of methylene blue. The resulting photooxidized fibrinogen was devoid of polymerization activity and thrombin-induced coagulability. The initial rate of the thrombin catalysed release of fibrinopeptides from photooxidized fibrinogen was normal. It was shown that illumination of photooxidized fibrinogen and photooxidized fragment N-DSK caused the modification of histidine residues. Tryptophan residues were also modified. When fibrinogen was photooxidized immediately after the addition of thrombin, the capacity to polymerize was lost. The inhibition of polymerization was less marked when oxidation was initiated at the time when polymerization began or thereafter. Photooxidized fibrinogen acts as an inhibitor of the polymerization of fibrin monomers. Photooxidized fibrinogen has affinity for thrombin-activated fibrinogen-Sepharose and thrombin-activated fragment N-DSK-Sepharose. When the former conjugate is illuminated in the presence of methylene blue its affinity for fibrinogen is decreased. It is concluded that the fragment N-DSK domain of fibrinogen is affected by photooxidation.

Rat homologue of the human M(r) 110000 antigen is the protein that expresses widely in various tissues.

The rat homologue of the human M(r) 110000 antigen, which cross-reacts with anti-carcinoembryonic antigen antibodies, was isolated from a rat lung cDNA library. The deduced amino acid sequence revealed a signal peptide, cysteine-rich and immunoglobulin-like region, serine-threonine region, and N-glycosylation sites in the extracellular portion. Northern blot analysis demonstrated a wide distribution of the mRNA in adult rat tissues and A10 rat vascular smooth muscle cells. Therefore, the rat homologue of the human M(r) 110000 antigen may be a receptor or a cell adhesion molecule rather than a specific carcinogenic antigen.

Significance of tryptophan residues in the D-domain of the fibrin molecule in fibrin polymer formation.

The modification of fibrin monomer with H2O2 caused reduction of the association activity of fibrin monomer. The association activity was not reduced even by modification of approx. 16 out of the total 64 tryptophan residues in the fibrin molecule; it was then abolished by further modification of the following several residues. Fragment D obtained by proteolysis of fibrinogen with plasmin, inhibited the association activity of fibrin monomer and the modification of approx. six out of the total 21 tryptophan residues in the fragment led to the complete loss of the inhibitory effect. It was concluded from these studies that about six tryptophan residues in the D-domain of fibrin are important for the association of fibrin monomer.

Functional consequences of tryptophan modification in human fibrinogen.

When human fibrinogen was modified with H2O2, inter- and intra-molecular cross-links of fibrinogen were formed, accompanied with oxidation of tryptophan, methionine and tyrosine residues. These cross-links may be closely associated with oxidation of tryptophan residues. The polymerization activity of fibrinogen with thrombin was decreased markedly by this modification. Modification of tryptophan residues in fibrinogen was also performed with 2-hydroxy-5-nitrobenzyl bromide. Modification of two out of a total 78 tryptophan residues in the molecule with the reagent led to the intensification (1.7 times) of the polymerization activity with thrombin and further modification of the next two residues led to complete loss of the polymerization activity. The first two tryptophan residues to be modified are in Fragment D, and the next two occur in Fragment E.

Ca2+- or Mg2+-dependent ATPase in plasma membrane of cultured endothelial cells from bovine carotid artery.

ATPase was found in plasma membrane of cultured endothelial cells from bovine carotid artery. The activity of the enzyme solubilized by octaethyleneglycol mono-n-dodecyl ether was enhanced by the addition of Ca2+ or Mg2+ and was not affected by F-actin and ouabain. Vmax was 2.8 and 10.0 mumol Pi/mg protein per h for Ca2+- and Mg2+-dependent activity, respectively, and the corresponding Km was 4.8 X 10(-4) M and 3.2 X 10(-4) M. Molecular weight of the protein was estimated to be approx. 250 000, as determined by activity-staining electrophoresis with polyacrylamide gels.

Triggering of the vascular permeability reaction by activation of the Hageman factor-prekallikrein system by house dust mite proteinase.

A 30-kilodalton (kDa) proteinase from the house dust mite Dermatophagoides farinae (Df-proteinase) was recently purified (Takahashi et al. (1990) Int. Arch. Allergy Appl. Immunol. 91, 80-85). In this paper we detailed the biological activities of the Df-proteinase. The activation of the kinin cascade by Df-proteinase was examined in vitro by using purified guinea pig Hageman factor (HF), prekallikrein (PK) and high-molecular-weight kininogen (HMWK) and the effect of this proteinase on endogenous human plasma proteinase inhibitors (serpins) and alpha 2-macroglobulin was tested. In addition, enhancement of the vascular permeability reaction in guinea pig skin by Df-proteinase was examined in vivo. These experiments showed that Df-proteinase could activate all the steps of the kinin-generating cascade, i.e., HF, PK and HMWK, and that Df-proteinase retained proteolytic activity even in the presence of an excess amount of endogenous proteinase inhibitors in plasma. We also found that the marked enhancement of the vascular permeability reaction was induced by Df-proteinase via the activation of the kinin-generating cascade without the release of histamine. From these results, we conclude that the proteinase of the house dust mite, Df-proteinase, has the potential to generate bradykinin and that the presence of this proteinase in biological systems would exacerbate inflammatory reactions in some pathological conditions.

Chemical modification of L-asparaginase with comb-shaped copolymer of poly(ethylene glycol) derivative and maleic anhydride.

L-asparaginase from Escherichia coli, an antitumor enzyme, was chemically modified with a comb-shaped copolymer of poly(ethylene glycol) derivative and maleic anhydride (activated PM). The PM-modified asparaginase lost the immunoreactivity with retaining high enzymic activity and also prolonged the clearance time in blood. Intraperitoneal administration of PM-asparaginase markedly increased the mean survival-time of lymphoma L5178Y-bearing mice in comparison with that of unmodified asparaginase. Pretreatment of mice with PM-asparaginase before immunizing with unmodified asparaginase extremely suppressed the anti-asparaginase antibody production.

Cell cycle arrest and apoptosis of leukemia cells induced by L-asparaginase.

Apoptotic cell death of murine leukemia cells induced by E. coli L-asparaginase was studied. Deprivation of L-asparagine from the culture of L5178Y cells by L-asparaginase caused the fragmentation of chromosomal DNA of the leukemia cells within 24 h. Prior to the degradation of DNA, cell cycles of L5178Y cells were found to be arrested in G1 phase, and evidence of the DNA strand breaks was initially observed in G1 phase cells as early as 8 h after the asparaginase treatment. Therefore, apoptosis of leukemia cells induced by L-asparaginase is an event that is associated with the cell cycle arrest in G1 phase.

Perineal-onset Fournier's gangrene in a patient undergoing hemodialysis--importance of perineal-onset manifestation.

We present a rare case of perineal-onset Fournier's gangrene in a patient undergoing hemodialysis. A 51-year-old Japanese man manifested an acute-onset perineal pain with perirectal abscess; subsequently, the pain extended to the abdomen, chest, and loin despite quick treatment. His consciousness deteriorated to delirium and he died of septic shock on the third day of admission. Computed tomography (CT) revealed soft-tissue air along the right rectal wall, moreover, the infection extended to the anterior wall of the bladder and the right peripsoas muscle. On the basis of the clinical course and CT findings, the patient was diagnosed as having the complications of Fournier's gangrene, however, no scrotal lesions were detected. Fournier's gangrene is considered to be easily diagnosed on the basis of skin lesions, such as scrotal erythema and swelling. However, in the early stage, the diagnosis of Fournier's gangrene is difficult in a patient with perineal pain before the detection of skin lesions. In conclusion, definitely the key to improving the prognosis of this fulminant infection is the prompt recognition of the pathological process. Therefore, Fournier's gangrene should always be considered when patients undergoing hemodialysis manifest perirectal disorders, even when no scrotal lesions are detected, because there is the possibility of intra-abdominal and intra-retroperitoneal infections resulting in septic shock.

Mechanical properties of a bioabsorbable nerve guide tube for long nerve defects.

The mechanical properties of nerve guide tubes must be taken into consideration when they are being developed. We previously reported the feasibility of using 50:50 tubes in a canine 40mm peroneal nerve defect model, where 50:50 represents the proportion of poly(L-lactic) acid (PLLA) and polyglycolic acid (PGA). The aim of the current study was to show that 50:50 tubes have suitable mechanical properties for repairing long nerve defects. Four types of nerve guide tubes made with PLLA to PGA fiber ratios of 100:0 (i.e. 100% PLLA) (100:0 tube), 50:50 (50:50 tube), 10:90 (10:90 tube), and 0:100 (0:100 tube) were designed and created using a tubular braiding machine. Their mechanical properties were examined in vitro (up to 16 weeks). In compression testing, 50:50 tubes had the highest normalized force value, followed in order by the 100:0, 10:90, and 0:100 tubes up to 8 weeks after immersion. From the point of view of biomechanics and bioresorbability, out of the 4 tube types tested, 50:50 tubes appeared to have the optimal mechanical properties for longer nerve defects.

Effect of combination antiretroviral therapy upon rectal mucosal HIV RNA burden and mononuclear cell apoptosis.

BACKGROUND: Pathogen-negative diarrhea is common in HIV infection and has been associated with clinical symptoms, histopathology, HIV expression, CD4+ lymphocyte depletion, cytokine mRNA expression, and apoptosis of lamina propria mononuclear cells. OBJECTIVES AND METHODS: To examine the short-term (7-day) effects of treatment with combination antiretroviral therapies upon gastrointestinal symptoms and rectal mucosa in 15 HIV-infected subjects. RESULTS: Treatment was associated with significant decreases in the perception of abdominal bloating and cramps. Similar declines in RNA burden and rises in CD4+ lymphocyte counts were found in blood and mucosa. Treatment was also associated with a fall in the number of lamina propria mononuclear cells undergoing apoptosis by in situ labeling, a change that correlated with the change in mucosal viral burden. CONCLUSIONS: Peripheral blood and mucosal compartments are equally responsive to effective antiretroviral therapies. The detection of significant changes within 7 days of starting antiviral therapy implies that intestinal dysfunction may be a direct result of local HIV infection.

Biomedical and biotechnological applications of PEG- and PM-modified proteins.

Chemical modification of proteins and other bioactive molecules with polyethylene glycol (PEG) or its derivatives (PM) can be used to tailor molecular properties to particular applications, eliminating disadvantageous properties or conferring new molecular functions. Complexes of therapeutic proteins and PEG or PM show reduced immunoreactivity, prolonged clearance times and improved biostability. Modification with PEG can also increase the solubility and activity of enzymes in organic solvents, thus extending their potential for application in organic syntheses and biotransformation processes.