Electrically induced ambipolar spin vanishments in carbon nanotubes.

Carbon nanotubes (CNTs) exhibit various excellent properties, such as ballistic transport. However, their electrically induced charge carriers and the relation between their spin states and the ballistic transport have not yet been microscopically investigated because of experimental difficulties. Here we show an electron spin resonance (ESR) study of semiconducting single-walled CNT thin films to investigate their spin states and electrically induced charge carriers using transistor structures under device operation. The field-induced ESR technique is suitable for microscopic investigation because it can directly observe spins in the CNTs. We observed a clear correlation between the ESR decrease and the current increase under high charge density conditions, which directly demonstrated electrically induced ambipolar spin vanishments in the CNTs. The result provides a first clear evidence of antimagnetic interactions between spins of electrically induced charge carriers and vacancies in the CNTs. The ambipolar spin vanishments would contribute the improvement of transport properties of CNTs because of greatly reduced carrier scatterings.

Simple suturing of the nasal septum using the Maniceps septum stitch device.

OBJECTIVE: To present the utility of the recently introduced Maniceps septum stitch device for suturing of the nasal septum. METHODS: This paper describes nasal septum suturing techniques using the Maniceps septum stitch device following septoplasty to prevent post-operative complications such as haematoma and nasal septum perforation. CONCLUSION: Nasal septum suturing using the Maniceps septum stitch device appears to be a safe and easy surgical procedure to help prevent post-operative complications and may reduce the incidence of nasal septum perforation following septoplasty.

Estimating trophic link density from quantitative but incomplete diet data.

The trophic link density and the stability of food webs are thought to be related, but the nature of this relation is controversial. This article introduces a method for estimating the link density from diet tables which do not cover the complete food web and do not resolve all diet items to species level. A simple formula for the error of this estimate is derived. Link density is determined as a function of a threshold diet fraction below which diet items are ignored ("diet partitioning function"). Furthermore, analytic relationships between this threshold-dependent link density and the generality distribution of food webs are established. A preliminary application of the method to field data suggests that empirical results relating link density to diversity might need to be revisited.

Telomere size and telomerase activity in Epstein-Barr virus (EBV)-positive and EBV-negative Burkitt's lymphoma cell lines.

The telomere repeat lengths of BL cell lines were quantified by measuring terminal restriction fragment (TRF). Epstein-Barr virus (EBV)-positive Namalwa, Raji, and EB-3 cell lines have long telomeres, i.e. TRFs 10-19 kbp, whereas the Daudi cell line, producing a transformation-defective EBV mutant, has TRFs approximately 2.2 kbp. EBV-negative BJAB and DG75 cell lines have short TRFs 3.9-5.4 kbp, shorter than the approximately 12 kbp TRFs in PBLs. Telomerase activities of these BL cell lines are similar. TRFs of non-BL lymphoma cell lines are 2.3-5.5 kbp. Fluorescent in situ hybridization (FISH) studies of these cell lines showed remarkable heterogeneity of telomere size in chromosomes in the same BL cell. These results suggest that EBV-positive and EBV-negative BL cell lines have experienced various telomere dynamics.

Elevated immunoglobulin G antibodies to the proline-rich amino-terminal region of Epstein-Barr virus nuclear antigen-2 in sera from patients with systemic connective tissue diseases and from a subgroup of Sjögren's syndrome patients with pulmonary involvements.

Associations of Epstein-Barr virus (EBV) and autoimmune diseases have been hypothesized. We have analysed IgG antibodies to EBV nuclear antigen (EBNA)-2 in sera from Japanese patients with autoimmune systemic connective tissue diseases (CTD), exemplified by systemic lupus erythematosus (SLE), primary Sjogren's syndrome (SS), rheumatoid arthritis (RA), systemic sclerosis (SSc) and secondary SS (classical CTDs complicated with SS). An enzyme-linked immunosorbent assay (ELISA) which uses glutathione-S-transferase polypeptides fused to EBV nuclear antigen (EBNA)-2 and EBNA-1 was developed. Ratios of IgG antibody reactivity to whole IgG concentrations of sera were calculated to normalize EBNA-2 and EBNA-1 antibody levels to the hypergammaglobulinaemia that occurs in CTD. The ELISA optical density OD(450) readings of IgG antibodies to both the amino-terminal aa 1-116 of EBNA-2 and carboxyl-terminal aa 451-641 of EBNA-1 were elevated significantly in patients with SLE, primary SS, RA, SSc and secondary SS when compared to EBNA-1. The OD readings were divided by serum IgG concentrations to normalize for the hypergammaglobulinaemia. The specific levels of IgG antibodies to the amino-terminal region of EBNA-2 were elevated in patients with SLE, primary SS or RA, as well as those with secondary SS complicated with SLE or RA. The EBNA-2 amino-terminal region contains a polyproline tract and a proline-rich sequence and has considerable amino acid sequence homology with many cellular proline-rich proteins. High ratios of EBNA-2 aa 1-116 to EBNA-1 aa 451-641 IgG antibody levels which probably suggest reactivation of EBV latent infection were associated significantly with pulmonary involvement in SS patients. These results are consistent with the hypothesis that the sequence similarity between the amino-terminal region of EBNA-2 and proline-rich cellular proteins is associated with pathogenesis in a subpopulation of CTD patients, possibly by the molecular mimicry-epitope shift mechanism.

A monoclonal antibody that recognizes Epstein-Barr virus nuclear antigen 2 (EBNA 2) amino acids 1-58 does not react with EBNA 2 in native form, consistent with the self-association of EBNA 2 through the amino-terminus.

We have generated a mouse IgG1 monoclonal antibody (mAb) that recognizes amino acids 1-58 of Epstein-Barr virus (EBV) nuclear antigen 2 (EBNA 2) of type 1 EBV strain B95-8. mAb Y101 also reacted with EBNA 2 of EBV type 2 strains MISP and Jijoye in immunoblots, whereas Jijoye EBNA 2 was not detected by the widely used mAb PE2. mAb Y101, in contrast to mAb PE2, reacted with faster migrated, hypophosphorylated proteins of type 1 EBNA 2 as intensely as slower migrated, hyperphosphorylated ones. mAb Y101 did not react in fixed-cell immunostaining or cell extract immunoprecipitation. The results implicate that the amino-terminal epitope is not exposed in a native form, consistent with the previously reported idea of self-association of EBNA 2 through the amino-terminus. mAb Y101 is the first mAb to the EBNA 2 amino-terminus and will be useful for further analyses of the structure and function of EBNA 2.

Conjugation length dependence of internal conversion in carotenoids: role of the intermediate state.

We report on a sub-20-fs transient absorption study of the S2(1(1)B(+)(u))-->S1(2(1)A(-)(g)) internal conversion in a series of carotenoids with a number of conjugated double bonds (N) ranging from 5 to 15. For the longer carotenoids (N>or=9), the measurements reveal the existence of an additional intermediate excited state lying between the optically allowed S2 state and the lower-lying forbidden S1 state. This state enables us to explain the nonmonotonic dependence of the S2-->S1 conversion rate on N and is expected to play an important role in photosynthetic light harvesting.

[Beating heart coronary artery bypass grafting for acute myocardial infarction].

We consider that off-pump coronary artery bypass grafting (CABG) [OPCAB], which results in local myocardial ischemia, is more effective for patients with acute myocardial infarction (AMI) than conventional CABG under cardiac arrest with global myocardial ischemia. Twenty-one patients (15 males, 6 females) received OPCAB for AMI, among whom surgery was performed following percutaneous coronary intervention (PCI) failure in 4 and PCI was performed prior to OPCAB in 2, while PCI was not performed in the remaining 15. Preoperatively, 16 patients had intraaortic balloon pumping (IABP), and 4 had IABP and percutaneous cardiopulmonary support (PCPS). The mean interval from onset to surgery was 11.7 (range 3 to 40) hours. In 20 cases, a complete revascularization was performed. The mean number of bypasses was 2.3 and OPCAB was carried out in 14 patients. In 2 cases, OPCAB was converted to on-pump beating CABG for complete revascularization. Fourteen patients (67%), each maintained with preoperative left ventricular ejection fraction (EF), were discharged with an elective bypass. Four patients died after on-pump beating CABG, in whom EF was lower than 10%. In addition, 3 died of low cardiac output syndrome (LOS) under PCPS and 1 of ventricular fibrillation. Based on our results, we considered that complete revascularization using OPCAB was effective for cases of AMI with PCI difficulty. However, in shock cases requiring PCPS, cardiac function was not improved even after revascularization. Therefore, it is necessary to study new procedures for shock cases during the period from onset to surgery.

Epstein-Barr virus nuclear antigen-1 colocalizes with lamin B1 in the nucleoplasm and along the nuclear rim.

Epstein-Barr virus nuclear antigen 1 (EBNA-1) is essential for the maintenance of latent EBV plasmids, and is also a transcriptional regulator. Nuclear lamins, components of the nuclear lamina, have also been found in the nucleoplasm. We report here that EBNA-1 coincided with lamin B1 in the nucleoplasm and around the nuclear rim during S-phase by confocal microscopy of cells transfected with EBNA-1 in the absence of EBV plasmids. Lamin B1, which is rarely detected in nuclear soluble fractions, was detected in chromatin and nuclear matrix fractions of the EBNA-1-expressing cells. These observations suggest that EBNA-1 colocalizes with lamin B1 in the subnuclear sites.

Operating point control system for a continuous flow artificial heart: in vitro study.

We proposed and developed a practical and effective servo control system for rotary blood pumps. A rotary blood pump for assisting the failing natural heart should be operated only in physiologically acceptable conditions. The operation of a rotary blood pump is based on the rotational speed of the impeller and pressure head. If the pump flow and the pressure head are set within an acceptable range, the driving condition is deemed normal condition, and this control system maintains the preset operating point by applying proportional and detective control (PD control). If the pump flow or pressure head is outside the acceptable range, the driving condition is determined to be abnormal condition, and this system operates the pump in a recovery fashion. If the driving condition is kept under abnormal conditions of sudden decrease of the flow, the condition is termed a suction condition. The controller releases the pump from the suction condition and later returns it to the normal condition. In this study, we evaluated these servo control modes of the centrifugal pump and confirmed whether the performance of this proposed operating point control system was practical.

System design of a bioartificial liver with a high performance hemodialyzer as an immunoisolator using a mathematical kinetic model.

We propose a new bioartificial liver (BAL) system equipped with a high performance hemodialyzer to act as an immunoisolation device. We discuss the design of the BAL system using a mathematical kinetic model with the experimentally obtained mass-transfer performances of various hemodialyzers. The mass transfer resistances of the hemodialyzers did not adversely influence the ammonia-removal and bioactive-substance-supply performances of the BAL system. A suitable hemodialyzer for the BAL system is available even at present using an engineering design. The remaining problems to be overcome before realizing clinical use of the BAL system are to increase the rate constant of the first order reaction of the BAL for ammonia metabolism and to develop a new method of blood access that can be used safely with long term reliability at a high blood flow rate (ca. 556 ml/min).

Recombinant human basic fibroblast growth factor (bFGF) stimulates periodontal regeneration in class II furcation defects created in beagle dogs.

Several growth factors (or cytokines) have been recently investigated for their use as potential therapeutics for periodontal tissue regeneration. The objective of this study was to evaluate periodontal tissue regeneration, including new bone and cementum formation, following topical application of recombinant basic fibroblast growth factor (bFGF, FGF-2) to furcation class II defects. Twelve furcation class II bone defects were surgically created in six beagle dogs, then recombinant bFGF (30 micro g/site) + gelatinous carrier was topically applied to the bony defects. Six weeks after application, periodontal regeneration was analyzed. In all sites where bFGF was applied, periodontal ligament formation with new cementum deposits and new bone formation was observed histomorphometrically, in amounts greater than in the control sites. Basic FGF-applied sites exhibited significant regeneration as represented by the new bone formation rate (NBR) (83.6 +/- 14.3%), new trabecular bone formation rate (NTBR) (44.1 +/- 9.5%), and new cementum formation rate (NCR) (97.0 +/- 7.5%). In contrast, in the carrier-only sites, the NBR, NTBR, and NCR were 35.4 +/- 8.9%, 16.6 +/- 6.2%, and 37.2 +/- 15.1%, respectively. Moreover, no instances of epithelial down growth, ankylosis, or root resorption were observed in the bFGF-applied sites examined. The present results indicate that topical application of bFGF can enhance considerable periodontal regeneration in artificially created furcation class II bone defects of beagle dogs.

Cyclic changes of granulocyte colony-stimulating factor (G-CSF) mRNA in the human follicle during the normal menstrual cycle and immunolocalization of G-CSF protein.

BACKGROUND: Ovulation has several similarities with inflammation and is closely connected to the activity of leukocytes and inflammatory cytokines. Since granulocytes are one of the major leukocytes, we focused our attention on the presence and local production of granulocyte colony-stimulating factor (G-CSF) in the human ovary. METHODS: The presence of G-CSF protein in the follicular fluid and perifollicular tissues was examined by Western blot analysis (n = 5) and immunohistochemical staining (n = 10). The relative expression levels of G-CSF mRNA in relation to GAPDH in granulosa, theca and luteal cells during the menstrual cycle were measured by quantitative RT-PCR using TaqMan technology (n = 15). RESULTS: G-CSF protein was detected in all follicular fluid and located mainly in granulosa cells of the follicle and luteal cells. The expression level of G-CSF mRNA in the late follicular phase was 137.6 +/- 18.5, which was approximately 10-fold greater than other phases during the menstrual cycle (P < 0.05). CONCLUSIONS: These results demonstrate that G-CSF is produced in the human follicle shortly before the ovulatory phase and may play an important role in the mechanism of ovulation.

Possible role of organ-specific autoantigen for Fas ligand-mediated activation-induced cell death in murine Sjögren's syndrome.

Activation-induced cell death (AICD) is a well-known mechanism of peripheral T cell tolerance that depends upon an interaction between Fas and Fas ligand (FasL). In this study, we demonstrate that the administration of a soluble form of anti-FasL Ab, FLIM58, results in severe destructive autoimmune exocrinopathy in the murine model of human Sjögren's syndrome (SS), and we found that an organ-specific autoantigen may play an important role on down-modulation of AICD. A high titer of serum autoantibodies against 120-kDa alpha-fodrin autoantigen was detected in the FLIM58-treated mice, and splenic T cell culture supernatants contained high levels of IFN-gamma. In vitro T cell apoptosis assay indicated that FasL-mediated AICD is down-regulated by autoantigen stimulation in spleen cells from the murine SS model, but not from Fas-deficient MRL/lpr mice and FasL-deficient MRL/gld mice. FasL undergo metalloproteinase-mediated proteolytic processing in their extracellular domains, resulting in the release of soluble trimeric ligands (soluble FasL). We showed that the processing of soluble FasL occurs in autoantigen-specific CD4(+) T cells, and that a significant increase in expressions of metalloproteinase-9 mRNA was observed in spleen cells from SS model mice. These findings indicate that the increased generation of soluble FasL inhibits the normal AICD process, leading to the proliferation of effector CD4(+) T cells in the murine SS model.

Amino acid substitution analyses of the DNA contact region, two amphipathic alpha-helices and a recognition-helix-like helix outside the dimeric beta-barrel of Epstein-Barr virus nuclear antigen 1.

OBJECTIVES AND METHODS: Epstein-Barr virus (EBV) nuclear antigen 1 (EBNA-1), which is essential for EBV latency, homodimerizes and binds to the EBV replication origin, oriP. We analyzed the dimerization/DNA-binding domain of EBNA-1 by random and site-directed amino acid substitution. RESULTS: Random point mutations that resulted in reduced DNA binding clustered in the DNA contact region (a.a. 461-473) and at or near the termini of alpha-helix II (514-527). Three substitutions of Gly in the DNA contact region each greatly reduced binding to a single binding site oligonucleotide. Substitutions at and near the termini of alpha-helix II diminished DNA binding. A helix-deforming substitution in alpha-helix I (477-489) blocked DNA binding. A helix-deforming substitution in alpha-helix III (568-582) abolished dimerization and DNA binding. Similarities in surface electrostatic properties and conserved amino acids were found between alpha-helix II and recognition helices of papillomavirus E2 proteins. CONCLUSIONS: The basic DNA contact region is crucial for the specific interaction of EBNA-1 with a single binding site. Alpha-helix I477 is indispensable for oriP binding, and alpha-helix III568 contributes to the homodimeric structure of EBNA-1. Alpha-helix II514 contributes to oriP binding, perhaps changing its alignment with DNA.

Epstein-Barr virus nuclear antigen-1-dependent and -independent oriP-binding cellular proteins.

OBJECTIVE: Epstein-Barr virus (EBV) nuclear antigen-1 (EBNA-1) and the replication origin, oriP, are essential for the replication and maintenance of latent EBV DNA in cells, but no enzymatic activity has been associated with EBNA-1 protein alone. In this study, we have searched for host cellular proteins that interact with EBNA-1 protein in various B cell lines latently infected with EBV, including a recently EBV growth-transformed cell line. METHODS: By using gel shift analysis, we investigated the interactions of an oligonucleotide containing a single EBNA-1 recognition site, derived from the family of repeats (FR) element of oriP, with protein from cell extracts. RESULTS: The FR oligonucleotide bound a (72-kD) cellular protein in the absence of EBNA-1 and without induction of the previously reported 'anti-EBNA-1 proteins'. The FR oligonucleotide formed complexes with additional proteins from EBNA-1-synthesizing cell lines; these complexes were abolished or supershifted by anti-EBNA-1 monoclonal antibodies. SDS-PAGE analyses of 35S-Met-labeled proteins that bound to a biotin- conjugated FR oligonucleotide, fractionated by a glycerol gradient centrifugation and affinity-purified with streptavidin, showed three major bands, a 72-kD protein, the FR binding of which seemed to be independent of EBNA-1, a 64-kD protein in both EBNA-1-transfected and latently EBV-infected cell lines, and a 45-kD protein in EBV-infected cell lines, which was most prominent in a recently EBV growth-transformed cell line. CONCLUSIONS: The FR element forms complexes with cellular proteins in the absence and presence of EBNA-1. These 72-, 64- and 45-kD cellular proteins might be involved in the function of the oriP and EBNA-1 system.

Effect of weak electric current on reducing oral bacteria in vitro.

The ions generated by weak electric current may be used for removal of dental plaque. Also, it has been judged from changes in the viable bacterial cell count and the amount of adenosine triphosphate (ATP) in the saliva that the passage of such a current also has a bactericidal effect on the oral microflora. We confirmed in vitro that 0.5 and 1.0 mA currents that passed for 10 min through phosphate buffered saline containing salivary bacteria were effective in killing the bacteria.

Glycyrrhizin increases survival of mice with herpes simplex encephalitis.

We examined the effect of glycyrrhizin (GR), a component of licorice root extract, on herpetic encephalitis that was inflicted on mice by inoculation of herpes simplex virus 1 (HSV-1) onto their cornea. Intraperitoneal (i.p.) administration of GR to mice suffering from herpetic encephalitis increased their survival rate in average about 2.5 times (from 37.5-29.0% to 81.8-83.3%; mean values from 2 experiments) while it reduced HSV-1 replication in the brain to 45.6% of the control. These results demonstrate a stimulative effect of GR on the mouse defense system(s) against HSV-1 infection.