A bispecific inhibitor of complement and coagulation blocks activation in complementopathy models via a novel mechanism

Inhibitors of complement and coagulation are present in the saliva of a variety of blood-feeding arthropods that transmit parasitic and viral pathogens. Here, we describe the structure and mechanism of action of the sand fly salivary protein lufaxin, which inhibits the formation of the central alternative C3 convertase (C3bBb) and inhibits coagulation factor Xa (fXa). Surface plasmon resonance experiments show that lufaxin stabilizes the binding of serine protease factor B (FB) to C3b but does not detectably bind either C3b or FB alone. The crystal structure of the inhibitor reveals a novel all β-sheet fold containing 2 domains. A structure of the lufaxin-C3bB complex obtained via cryo-electron microscopy (EM) shows that lufaxin binds via its N-terminal domain at an interface containing elements of both C3b and FB. By occupying this spot, the inhibitor locks FB into a closed conformation in which proteolytic activation of FB by FD cannot occur. C3bB-bound lufaxin binds fXa at a separate site in its C-terminal domain. In the cryo-EM structure of a C3bB-lufaxin-fXa complex, the inhibitor binds to both targets simultaneously, and lufaxin inhibits fXa through substrate-like binding of a C-terminal peptide at the active site as well as other interactions in this region. Lufaxin inhibits complement activation in ex vivo models of atypical hemolytic uremic syndrome (aHUS) and paroxysmal nocturnal hemoglobinuria (PNH) as well as thrombin generation in plasma, providing a rationale for the development of a bispecific inhibitor to treat complement-related diseases in which thrombosis is a prominent manifestation.

Stealth oxime ether lipid vesicles promote delivery of functional DsiRNA in human lung cancer A549 tumor bearing mouse xenografts

We previously reported that hydroxylated oxime ether lipids (OELs) efficiently deliver functional Dicer substrate siRNAs (DsiRNAs) in cells. Here, we explored in vivo utility of these OELs, using OEL4 as a prototype and report that surface modification of the OEL4 formulations was essential for their in vivo applications. These surface-modified OEL4 formulations were developed by inclusion of various PEGylated lipids. The vesicle stability and gene knock-down were dependent on the PEG chain length. OEL4 containing DSPE-PEG350 and DSPE-PEG1000 (surprisingly not DSPE2000) promoted gene silencing in cells. In vivo studies demonstrated that OEL4 vesicles formulated using 3 mol% DSPE-PEG350 accumulate in human lung cancer (A549-luc2) xenografts in mice and exhibit a significant increase in tumor to liver ratios. These vesicles also showed a statistically significant reduction of luciferase signal in tumors compared to untreated mice. Taken together, the scalable OEL4:DSPE-PEG350 formulation serves as a novel candidate for delivery of RNAi therapeutics.

Direct epitranscriptomic regulation of mammalian translation initiation through N4-acetylcytidine

mRNA function is influenced by modifications that modulate canonical nucleobase behavior. We show that a single modification mediates distinct impacts on mRNA translation in a position-dependent manner. Although cytidine acetylation (ac4C) within protein-coding sequences stimulates translation, ac4C within 5' UTRs impacts protein synthesis at the level of initiation. 5' UTR acetylation promotes initiation at upstream sequences, competitively inhibiting annotated start codons. Acetylation further directly impedes initiation at optimal AUG contexts: ac4C within AUG-flanking Kozak sequences reduced initiation in base-resolved transcriptome-wide HeLa results and in vitro utilizing substrates with site-specific ac4C incorporation. Cryo-EM of mammalian 80S initiation complexes revealed that ac4C in the -1 position adjacent to an AUG start codon disrupts an interaction between C and hypermodified t6A at nucleotide 37 of the initiator tRNA. These findings demonstrate the impact of RNA modifications on nucleobase function at a molecular level and introduce mRNA acetylation as a factor regulating translation in a location-specific manner.

Crystal Structure of a Soluble APOBEC3G Variant Suggests ssDNA to Bind in a Channel that Extends between the Two Domains

APOBEC3G (A3G) is a single-stranded DNA (ssDNA) cytosine deaminase that can restrict HIV-1 infection by mutating the viral genome. A3G consists of a non-catalytic N-terminal domain (NTD) and a catalytic C-terminal domain (CTD) connected by a short linker. While the CTD catalyzes cytosine deamination, the NTD is believed to provide additional affinity for ssDNA. Structures of both A3G domains have been solved individually; however, a full-length A3G structure has been challenging. Recently, crystal structures of full-length rhesus macaque A3G variants were solved which suggested dimerization mechanisms and RNA binding surfaces, whereas the dimerization appeared to compromise catalytic activity. We determined the crystal structure of a soluble variant of human A3G (sA3G) at 2.5 Å and from these data generated a model structure of wild-type A3G. This model demonstrated that the NTD was rotated 90° relative to the CTD along the major axis of the molecule, an orientation that forms a positively charged channel connected to the CTD catalytic site, consisting of NTD loop-1 and CTD loop-3. Structure-based mutations, in vitro deamination and DNA binding assays, and HIV-1 restriction assays identify R24, located in the NTD loop-1, as essential to a critical interaction with ssDNA. Furthermore, sA3G was shown to bind a deoxy-cytidine dinucleotide near the catalytic Zn²⁺, yet not in the catalytic position, where the interactions between deoxy-cytidines and CTD loop-1 and loop-7 residues were different from those formed with substrate. These new interactions suggest a mechanism explaining why A3G exhibits a 3' to 5' directional preference in processive deamination.

Mechanism for APOBEC3G catalytic exclusion of RNA and non-substrate DNA

The potent antiretroviral protein APOBEC3G (A3G) specifically targets and deaminates deoxycytidine nucleotides, generating deoxyuridine, in single stranded DNA (ssDNA) intermediates produced during HIV replication. A non-catalytic domain in A3G binds strongly to RNA, an interaction crucial for recruitment of A3G to the virion; yet, A3G displays no deamination activity for cytidines in viral RNA. Here, we report NMR and molecular dynamics (MD) simulation analysis for interactions between A3Gctd and multiple substrate or non-substrate DNA and RNA, in combination with deamination assays. NMR ssDNA-binding experiments revealed that the interaction with residues in helix1 and loop1 (T201-L220) distinguishes the binding mode of substrate ssDNA from non-substrate. Using 2′-deoxy-2′-fluorine substituted cytidines, we show that a 2′-endo sugar conformation of the target deoxycytidine is favored for substrate binding and deamination. Trajectories of the MD simulation indicate that a ribose 2′-hydroxyl group destabilizes the π-π stacking of the target cytosine and H257, resulting in dislocation of the target cytosine base from the catalytic position. Interestingly, APOBEC3A, which can deaminate ribocytidines, retains the ribocytidine in the catalytic position throughout the MD simulation. Our results indicate that A3Gctd catalytic selectivity against RNA is dictated by both the sugar conformation and 2′-hydroxyl group.

Frequency and features of myasthenia gravis developing after thymectomy

BACKGROUND AND PURPOSE

Thymectomy is an effective treatment for myasthenia gravis (MG) with anti-acetylcholine receptor (AChR) antibodies. We rarely encounter patients who develop MG after surgery for thymic tumors. This study aimed to investigate the characteristics and frequency of post-thymectomy onset (PostTx) MG.

METHODS

We reviewed the clinical information of thymoma-associated MG in 158 patients. Of these, 18 (11%) patients with PostTx MG were identified.

RESULTS

The presence of anti-AChR antibodies (82%) and electrophysiological abnormalities (50%) was confirmed before thymectomy in patients with PostTx MG. The clinical characteristics of PostTx MG were similar to those of pre-thymectomy onset (PreTx) MG. In PostTx MG, the duration between thymectomy and MG onset were distributed as < 6 months (early-onset PostTx MG) and ≥ 6 months (late-onset PostTx MG). Notably, some patients with late-onset PostTx MG were associated with thymoma relapse.

CONCLUSION

Our results suggest that approximately 11% of patients with thymoma-associated MG were PostTx MG and pre-surgical assessment of anti-AChR antibody titer or electrophysiological testing may predict PostTx MG development. However, no difference in clinical manifestation and prognosis was observed between PreTx MG and PostTx MG.

Safety of tapering tacrolimus dose in patients with well-controlled anti-acetylcholine receptor antibody-positive myasthenia gravis

BACKGROUND AND PURPOSE

Tapering immunosuppressants is desirable in patients with well-controlled myasthenia gravis (MG). However, the association between tapering of calcineurin inhibitor dosage and reduction-associated exacerbation is not known. The aim of this study was to clarify the frequency of reduction-associated exacerbation when tacrolimus is tapered in stable patients with anti-acetylcholine receptor antibody-positive MG, and to determine the factors that predict exacerbations.

METHODS

We retrospectively analyzed 115 patients in whom tacrolimus dosage was tapered. The reduction-associated exacerbation was defined as the appearance or worsening of one or more MG symptoms <3 months after the reduction.

RESULTS

Tacrolimus dosage was successfully tapered in 110 patients (96%) without any exacerbation. Five patients (4%) experienced an exacerbation, but symptoms were reversed in all patients when the tacrolimus dose was increased to the previous maintenance level. No patient developed an MG crisis. The age at onset was significantly earlier (30 vs. 56 years, P = 0.025) and the reduction in dosage was significantly larger (2.0 vs. 1.0 mg/day, P = 0.002) in patients with reduction-associated exacerbation than in those without exacerbation. The cut-off values determined in a receiver-operating characteristic curve analysis were 52 years (sensitivity, 57%; specificity, 100%) for the age at onset and 1.5 mg (sensitivity, 80%; specificity, 100%) for the dose reduction.

CONCLUSION

Tapering of tacrolimus was possible in most patients with well-controlled anti-acetylcholine receptor antibody-positive MG. Early age at onset and a large reduction from maintenance dosage were associated with exacerbation. Reductions ≤1.5 mg/day from the maintenance dosage should be considered for patients with late-onset disease.

First report of hepatobiliary Mycobacterium avium infection developing obstructive jaundice in a patient with neutralizing anti-interferon-gamma autoantibodies

This study describes a patient who experienced hepatobiliary Mycobacterium avium infection associated with neutralizing anti–interferon gamma (IFN-γ) autoantibodies during treatment for disseminated M. avium disease. Hepatobiliary M. avium infection should be considered in jaundiced patients with neutralizing anti–IFN-γ autoantibodies, including those receiving antimycobacterial therapy for disseminated M. avium disease.

Crystal structure of the catalytic domain of HIV-1 restriction factor APOBEC3G in complex with ssDNA

The human APOBEC3G protein is a cytidine deaminase that generates cytidine to deoxy-uridine mutations in single-stranded DNA (ssDNA), and capable of restricting replication of HIV-1 by generating mutations in viral genome. The mechanism by which APOBEC3G specifically deaminates 5′-CC motifs has remained elusive since structural studies have been hampered due to apparently weak ssDNA binding of the catalytic domain of APOBEC3G. We overcame the problem by generating a highly active variant with higher ssDNA affinity. Here, we present the crystal structure of this variant complexed with a ssDNA substrate at 1.86 Å resolution. This structure reveals atomic-level interactions by which APOBEC3G recognizes a functionally-relevant 5′-TCCCA sequence. This complex also reveals a key role of W211 in substrate recognition, implicating a similar recognition in activation-induced cytidine deaminase (AID) with a conserved tryptophan.

APOBEC3G (A3G) is a single-stranded DNA (ssDNA) cytidine deaminase that restricts HIV-1. Here the authors provide molecular insights into A3G substrate recognition by determining the 1.86 Å resolution crystal structure of its catalytic domain bound to ssDNA.

Abstract P3-01-05: A feasibility study of sentinel lymph node detection and analysis of safety to omit axillary lymph node dissection in clinically node-negative breast cancer patients after neoadjuvant chemotherapy

Background: Concerns still remain about lower sentinel node (SN) detection and higher false-negative rates (FNR) in breast cancer patients treated with neoadjuvant chemotherapy (NAC), especially those who are clinically node-positive before NAC. It is necessary to analyze the validity of sentinel node biopsy (SNB) after NAC and evaluate whether the SN identification rate and FNR for clinically N0 (cN0) patients after NAC would be acceptable or not in order to omit axillary lymph node dissection (ALND).

Objectives and methods: We identified SN by radioisotopic methods followed by completion of ALND in cN0 patients after NAC from 2013 to 2016 as part of a clinical research study (SNB group, N=68) to analyze the accuracy of SNB, and retrospectively investigated the prognosis of patients treated with NAC from 2006 to 2012 (control group, N=92) to evaluate whether the validity of SNB would be acceptable or not.

Results: Mean patient ages in the SNB group and control group were 51.0 years and 49.5 years, respectively (p=0.17), and the distribution of intrinsic subtypes was not significantly different between the two groups. The numbers of cN1≤ before NAC in the SNB group and control group were 85.5% (57/68) and 80.4% (74/92), respectively (p=0.58), and the pathological complete response rates were 25.0% (17/68) and 19.6% (18/92), respectively (p=0.41). Lymphoscintigraphy using 99mTc-phytate acid was performed in the SNB group, and hot spots were detected at the ipsilateral axilla in 62 of 68 (91.2%) patients, in all of whom SNs could be identified by using a gamma-probe. The FNR, which indicates no metastasis in SNs and metastasis in non-SN, was 5.9% (4/68). Among these four patients, three were of the luminal type while one was triple negative. The number of patients without metastasis in both SN and non-SN, which are candidates for omission of ALND, was 26 of 68 (38.2%). They included eight of nine HER2-enriched patients and six of 13 luminal-HER2 patients. Conversely, there were no false-negative cases in these subtypes. Moreover, all SNs were identified even if there were metastases in SNs. Regarding the prognosis of the control group, the 10-year disease free survival of post-NAC N0 (ypN0) (52/92, 56.5%) and ypN1≤ (40/92, 43.5%) were 80.7% and 61.2%, respectively (p=0.08); in addition, the 10-year overall survival of yN0 and ypN1≤ were 90.4% and 72.6% (p=0.26). Thus, the prognosis of ypN1≤ was not significantly inferior to that of ypN0. If omission of ALND were performed for false negative cases, then the risk of axillary relapse would be a concern. However, these data indicate the possibility that 5.9% of FNR as shown in the SNB group would not have much influence on prognosis.

Conclusion: The accuracy of SN detection by radioisotopic methods for cN0 breast cancer after NAC was not maintained like that for -early breast cancer although it was better than the results of previous studies. However, there were no false-negative cases in HER2-enriched and luminal-HER2 subtypes, which could be potential candidates for omission of ALND. In addition, omission of ALND for false-negative patients would have less influence on the prognosis.

Citation Format: Maeno K, Yamamoto K, Ono M, Oba T, Iesato A, Ono K, Ito T, Kanai T, Ito K-I. A feasibility study of sentinel lymph node detection and analysis of safety to omit axillary lymph node dissection in clinically node-negative breast cancer patients after neoadjuvant chemotherapy [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P3-01-05.

Significance of measurement of serum trough level and anti-drug antibody of adalimumab as personalised pharmacokinetics in patients with Crohn's disease: a subanalysis of the DIAMOND trial

BACKGROUND

Significance of monitoring adalimumab trough levels and anti-adalimumab antibodies (AAA) for disease outcome in Crohn's disease (CD) patients remained unclear.

AIM

To evaluate the association of adalimumab trough levels and AAA at week 26 with clinical remission at week 52, the effect of azathiopurine on AAA and factors influencing trough levels in CD patients in the DIAMOND trial.

METHODS

We performed this study using adalimumab trough levels, AAA at week 26 and 6-thioguanine nucleotide (TGN) in red blood cells at week 12. A multiple regression model and receiver operating analysis was performed to identify factors influencing adalimumab trough levels and AAA, and adalimumab thresholds for predicting disease activity.

RESULTS

There was a significant difference of adalimumab trough level at week 26 between patients with disease remission and without at week 52 (7.7 ± 3.3 μg/mL vs 5.4 ± 4.3 μg/mL: P <.001). Adalimumab trough level of 5.0 μg/mL yielded optimal sensitivity and specificity for remission prediction (80.2% and 55.6%, respectively). AAA development at week 26 significantly affected remission at week 52 (P = .021), which was strongly associated with adalimumab trough levels. Female gender and increasing body weight were independently associated with low adalimumab trough levels, and female gender was associated with AAA development. A cut-off 6TGN level of >222.5 p mol/8 ×10⁸ RBCs yielded sensitivity (100%) and specificity (60.6%) for AAA negativity.

CONCLUSION

Adalimumab trough levels and AAA occurrence were significantly associated with clinical remission. Higher 6TGN affected AAA negativity. The combination therapy is beneficial in some relevant aspects for CD patients. (UMIN Registration No. 000005146).

Fluence correction factor for graphite calorimetry in a clinical high-energy carbon-ion beam

The aim of this work is to develop and adapt a formalism to determine absorbed dose to water from graphite calorimetry measurements in carbon-ion beams. Fluence correction factors, [Formula: see text], needed when using a graphite calorimeter to derive dose to water, were determined in a clinical high-energy carbon-ion beam. Measurements were performed in a 290 MeV/n carbon-ion beam with a field size of 11  ×  11 cm², without modulation. In order to sample the beam, a plane-parallel Roos ionization chamber was chosen for its small collecting volume in comparison with the field size. Experimental information on fluence corrections was obtained from depth-dose measurements in water. This procedure was repeated with graphite plates in front of the water phantom. Fluence corrections were also obtained with Monte Carlo simulations through the implementation of three methods based on (i) the fluence distributions differential in energy, (ii) a ratio of calculated doses in water and graphite at equivalent depths and (iii) simulations of the experimental setup. The [Formula: see text] term increased in depth from 1.00 at the entrance toward 1.02 at a depth near the Bragg peak, and the average difference between experimental and numerical simulations was about 0.13%. Compared to proton beams, there was no reduction of the [Formula: see text] due to alpha particles because the secondary particle spectrum is dominated by projectile fragmentation. By developing a practical dose conversion technique, this work contributes to improving the determination of absolute dose to water from graphite calorimetry in carbon-ion beams.

Nanoscale Characterization of Interaction of APOBEC3G with RNA

The human cytidine deaminase APOBEC3G (A3G) is a potent inhibitor of the HIV-1 virus in the absence of viral infectivity factor (Vif). The molecular mechanism of A3G antiviral activity is primarily attributed to deamination of single-stranded DNA (ssDNA); however, the nondeamination mechanism also contributes to HIV-1 restriction. The interaction of A3G with ssDNA and RNA is required for its antiviral activity. Here we used atomic force microscopy to directly visualize A3G-RNA and A3G-ssDNA complexes and compare them to each other. Our results showed that A3G in A3G-RNA complexes exists primarily in monomeric-dimeric states, similar to its stoichiometry in complexes with ssDNA. New A3G-RNA complexes in which A3G binds to two RNA molecules were identified. These data suggest the existence of two separate RNA binding sites on A3G. Such complexes were not observed with ssDNA substrates. Time-lapse high-speed atomic force microscopy was applied to characterize the dynamics of the complexes. The data revealed that the two RNA binding sites have different affinities for A3G. On the basis of the obtained results, a model for the interaction of A3G with RNA is proposed.

Correction: A narrow amide I vibrational band observed by sum frequency generation spectroscopy reveals highly ordered structures of a biofilm protein at the air/water interface

Correction for 'A narrow amide I vibrational band observed by sum frequency generation spectroscopy reveals highly ordered structures of a biofilm protein at the air/water interface' by Zhuguang Wang et al., Chem. Commun., 2016, 52, 2956-2959.

An Effective New Cryopreservation Procedure for Pancreatic Islets Using Hollow Fiber Vitrification

The present study aimed at establishing a new cryopreservation method for mouse pancreatic islets by vitrification using hollow fibers as a container. A unique feature of the hollow fiber vitrification (HFV) method is that this method achieves stable vitrification using a minimum volume of cryoprotectant (CPA) solution, thereby ensuring high viability of the islets. The cytotoxicity, optimum composition, and concentration of the CPAs for vitrifying islets were examined. The viability, functional-integrity of vitrified islets were evaluated in comparison with those vitrified by conventional methods. Insulin secretion was measured in vitro by a static incubation assay and the metabolic functions was tested after transplantation into Streptozotocin-induced diabetic mice. The combination of 15% dimethyl sulfoxide+15% ethylene glycol resulted in the best CPA solution for the HFV of islets. HFV showed the highest viability in comparison to 2 vitrification methods, open pulled straws and vitrification with EDT324 solution. The vitrified islets stably expressed β-cells markers NeuroD, Pancreatic and duodenal homeobox-1, and MafA. Transplantation of the vitrified islets achieved euglycemia of the host diabetic mice and response to an intraperitoneal glucose tolerance test to a similar extent as non-vitrified transplanted islets. The HFV method allows for efficient long-term cryopreservation of islets.

A narrow amide I vibrational band observed by sum frequency generation spectroscopy reveals highly ordered structures of a biofilm protein at the air/water interface

We characterized BslA, a bacterial biofilm protein, at the air/water interface using vibrational sum frequency generation spectroscopy and observed one of the sharpest amide I bands ever reported. Combining methods of surface pressure measurements, thin film X-ray reflectivity, and atomic force microscopy, we showed extremely ordered BslA at the interface.

Antimicrobial activity of hyperbranched polymers: Synthesis, characterization, and activity assay study

Poly(cyanurateamine) and poly(triacrylatetrimine) hyperbranched polymers were synthesized for the first time by adopting Michael addition reaction. These polymers were obtained by reacting diethylenetriamine (A2) with 2,4,6-triallylcyanurate (B3) and trimethylolpropane triacrylate (B3), respectively, at room temperature. The polymers were characterized by spectroscopic techniques such as Fourier transform infrared, 1H-, and 13C-nuclear magnetic resonance spectroscopy. The antimicrobial activity of hyperbranched polymers was studied against Staphylococcus aureus ATCC 25923, Escherichia coli, Bacillus firmus, Bacillus subtilis MTCC 2423, Serratia marcescens, Pseudomonas aeruginosa, Micrococcus sp., and Acinetobacter beijerinckii. Both poly(cyanurateamine) and poly(triacrylatetrimine) show good antibacterial activity against gram-positive bacteria compared to gram-negative bacteria. Interestingly, poly(triacrylatetrimine) is better resistant to promising antibiotics and antiseptics bacteria, Pseudomonas aeruginosa and Serratia marcescens in comparison with poly(cyanurateamine).

Serum cytokine and chemokine profiles in patients with myasthenia gravis

Myasthenia gravis (MG) is an autoimmune-mediated inflammatory disease of the neuromuscular junction. Previous studies of animal MG models have suggested important roles of cytokines in MG pathogenesis, but adequate studies on cytokines in human MG are lacking. Using a multiplex suspension array system, we measured the serum levels of 27 cytokines/chemokines in 47 anti-acetylcholine receptor antibody-positive patients with MG and 20 normal controls (NC) to investigate the contribution of cytokines/chemokines toward MG pathogenesis. Correlations between clinical parameters and cytokine/chemokine levels in patients with MG were also examined. The serum levels of interleukin (IL)-15 (mean ± standard deviation: 6·85 ± 6·97 pg/ml) and vascular endothelial growth factor (VEGF) (96·21 ± 71·60 pg/ml) significantly increased, whereas IL-4 levels (3·57 ± 0·86 pg/ml) decreased in patients with MG compared with NC (IL-15: 4·42 ± 1·55 pg/ml; VEGF: 63·51 ± 32·95 pg/ml; IL-4: 4·15 ± 0·81 pg/ml, P < 0·05). In addition, eight cytokines (IL-4, IL-8, IL-15, eotaxin, macrophage inflammatory protein-1α, macrophage inflammatory protein-1β, VEGF and IL-1b) were significantly changed among MG patients with thymoma, MG patients without thymoma and NC (P < 0·05). Some cytokines, such as IL-4, IL-15, and VEGF, may play roles in the pathogenesis of MG.

Operation status of the electron cyclotron resonance ion source at Gunma University

An ECR ion source of Gunma University Heavy Ion Medical Center, so-called KeiGM [M. Muramatsu, A. Kitagawa, Y. Sakamoto, S. Sato, Y. Sato, H. Ogawa, S. Yamada, H. Ogawa, Y. Yoshida, and A. G. Drentje, Rev. Sci. Instrum. 76, 113304 (2005)], has been operated for cancer therapy and physical/biological experiment since 2010. KeiGM produces typically 230 μA of 10 keV/u C(4+) ions from CH4 gases. The vacuum pressure is kept between 1.2 × 10(-4) and 1.7 × 10(-4) Pa so as to suppress the pulse-to-pulse current fluctuation within ±10%. The extraction electrode is cleaned every 6-8 months in order to remove deposited carbon, which increases the leak current and discharge. In order to investigate the possibility of long-term operation without such maintenances, oxygen aging for the cleaning of the extraction electrode has been tested in the test bench. The same-designed ion sources at National Institute of Radiological Sciences and SAGA Heavy Ion Medical Accelerator in Tosu (SAGA-HIMAT) are also operated with stable C(4+) current, which are suitable for the continuous operation for cancer therapy.

26 IN VIVO EXOGENIC ORGAN GENERATION WITH ORGANOGENESIS-DISABLED CLONED PIGS AS A PLATFORM

The generation of organs from pluripotent stem cells (PSC) is one of the ultimate goals of regenerative medicine. We have demonstrated that functional organs can be generated in vivo from xenogenic PSC in the body of organogenesis-disabled mice using blastocyst complementation. To apply this principle in generating human organs, a technical platform using large non-rodent mammals is essential. The aim of the present study was to establish a blastocyst complementation system using cloned pig embryos. We generated transgenic-cloned pigs with an apancreatic phenotype via the overexpression of Hes1 (hairy and enhancer of split-1) under the Pdx1 promoter (pancreatic and duodenal homeobox-1). Cloned embryos of apancreatic pigs (host embryos, male) were complemented (i.e. chimerized) by blastomeres of cloned embryos (donor cells, female) with normal developmental competence. Chimeric embryos were cultured for 1 or 2 days before being transferred into the uteri of oestrus-synchronized gilts. The complementation of 292 Pdx1-Hes1 cloned embryos gave rise to 260 (89.0%) blastocysts. The transfer of these blastocysts resulted in 5 male chimeric pigs. Chimerism was confirmed by the detection of host embryo-derived Pdx1-Hes1 and marker transgenes of the donor cells, such as humanized Kusabira-Orange (huKO) or Pdx1-Venus. Chimeric pigs possessed normally formed pancreata entirely derived from the exogenous donor cells. We thus established a blastocyst complementation system in the pig using cloned embryos that would otherwise give rise to apancreatic animals. Chimeric pigs obtained developed normally, maintaining normal serum glucose concentrations up to maturity, and became fertile boars. Mating the chimeric boars with 7 wild-type sows gave rise to 72 fetuses/piglets of which 37 (51.4%) exhibited the apancreatic phenotype. These results indicate that a missing organ can be generated from exogenous cells when functionally normal pluripotent cells chimerize with a cloned dysorganogenetic embryo. Blastocyst complementation using cloned porcine embryos may permit the use of a large animal for the generation of functional organs from xenogenic PSC, including human iPSC. The chimeric boar produced by blastocyst complementation sired fetuses/offspring with the apancreatic phenotype in a Mendelian fashion. Porcine fetuses with an organogenesis-disabled phenotype may provide a useful platform for organ regeneration research. Table 1.Production of chimeric pigs by complementation and of Pdx1-Hes1 cloned embryos

20 GENERATION AND CHARACTERIZATION OF TRANSGENIC-CLONED PIGS EXPRESSING THE FAR-RED FLUORESCENT PROTEIN MONOMERIC PLUM

Transgenic (Tg) pigs expressing a fluorescent protein are extremely useful for research into transplantation and regenerative medicine. This study aimed to create Tg pigs expressing monomeric Plum (mPlum), a far-red fluorescent protein with a longer wavelength than enhanced green fluorescent protein (EGFP) and humanized Kusabira Orange (huKO), the two fluorescent proteins that have been used previously for Tg pig production. A linearized CAG-mPlum transgene construct was transferred into porcine fetal fibroblasts (PFF) by electroporation. mPlum fluorescence-positive cells were collected using a cell sorter and used as nuclear donors (mPlum-PFF) for somatic cell nuclear transfer (SCNT). In vitro-matured oocytes were obtained from porcine cumulus–oocyte complexes cultured in NCSU23-based medium and were used to obtain recipient oocytes for SCNT after enucleation. Then, SCNT was performed as reported previously (Matsunari et al., 2008). The reconstructed embryos were cultured for 7 days in porcine zygote medium-5 (PZM-5). mPlum fluorescence expression was screened during the early development of the embryos. After 5 or 6 days of culture, the SCNT embryos were surgically transferred to the uterus of a recipient gilt. We first obtained fetuses on Day 36 or 37 of gestation by Caesarean section and the PFF were retrieved from their skin. Fluorescence expression was analysed using fluorescence microscope, and the number of transgene copies in each fetus was determined by Southern blot analysis. We also analysed whether unique spectral properties of mPlum are suitable for multicolor imaging using confocal microscope and flow cytometer. The identification of mPlum-expressing PFF under the mixed culture of PFF expressing EGFP and huKO was examined. The 2 cell lines of PFF expressing EGFP and huKO were previously generated in our laboratory. Rates of normal cleavage and blastocyst formation occurred in the SCNT embryos generated with mPlum-PFF (mPlum embryos) were equivalent to those of SCNT embryos derived from nontransgenic PFF (34/42, 81.0%; 33/42, 78.6% v. 37/40, 92.5%; 30/40, 75.0%). Total cell numbers in mPlum and control blastocysts did not differ significantly (88.3 ± 6.0 v. 99.9 ± 8.8). Fluorescence expression in the mPlum embryos began at the 8-cell stage and became brighter from the morula stage. The gilt into which 103 mPlum embryos were transferred produced 3 fetuses. These fetuses expressed mPlum fluorescence systemically and had 1 to 5 copies of the transgene. Multicolor fluorescence imaging and flow cytometric analyses of a mixed culture of mPlum PFF and PFF expressing EGFP and huKO showed that clear identification and isolation of cells displaying each of the 3 fluorescence signals was possible. These observations demonstrate that the transfer of CAG-mPlum did not interfere with the development of porcine SCNT embryos and resulted in the successful generation of Tg cloned pigs that systemically expressed mPlum. This work was supported by JSPS KAKENHI Grant Number 25293279.

Scale-up Rule for Double Bubble Tubular Process of PA6 Film

The analysis of scale-up rule for double bubble tubular film process of PA6 was investigated. The scale-up rule previously proposed for a blown film process by the authors was applied to a double bubble tubular film process with a small-scale plant for research (pilot plant) and a large-scale plant for commercial production (production plant).

According to the scale-up rule based on the equivalent stretching stress between the pilot and production plants, the equivalence of stretching stability, birefringence pattern and deformation pattern were confirmed.

It has been confirmed that the proposed scale-up rule is applicable to predict the physical properties such as film impact strength and the bubble stability for the large-scale tubular film process on the basis of the experimental results obtained from the pilot plant.

Dynamics of Double Bubble Tabular Film Process for Producing Biaxially oriented Nylon 6 Film

A double bubble tubular film process for nylon 6 was investigated. This report discussed three topics: Relationship between process conditions and film stretching stresses; deformation rate during double bubble process, birefringence and film thickness uniformity; and scale-up rule for double bubble tubular film process. The optimum stretching stress during the double bubble tubular film process exists. The bubble break occurs over stress of 1300 Kg/cm2 and bubble stability occurs below stress of 600 Kg/cm2. The cross point of stretching stress, which means stress in the machine direction is equal to stress in the transverse direction, is influenced by a deformation rate which is closely related to birefringence and bubble stability. Bubble stability and film thickness uniformity are improved with increasing deformation rate. It is found that the scale-up rule which was set up theoretically is applicable to predict the physical properties and bubble stability for large scale double bubble tubular film process once the same process is carried out by using the same scale machine and a small amount of resin.

Prediction of Birefringence for Optical Memory Disk

Polycarbonate (PC) is considered to be a proper resin for optical memory disk, however PC resin shows high birefringence. It is very important to reduce birefringence of PC optical memory disk. This research is to obtain the relationship between birefringence and process conditions and to get the optimum condition for the production of low birefringence substrate of PC optical memory disk. The birefringence distribution of PC optical memory disk was theoretically predicted by the calculations of both the stress distribution caused by molecular orientation during the filling stage and the thermal stress caused by temperature difference during the cooling stage. The relationship between birefringence distribution and the process conditions such as rheological properties of PC resin, injection temperature, mold temperature, mold design and annealing condition is possible to be predicted theoretically by calculating shear stress during the injection process and thermal stress during the cooling process. The predicted results of birefringence distribution qualitatively agree with the experimental ones.

Thickness Uniformity of Double Bubble Tubular Film Process for Producing Biaxially Oriented PA 6 Film

It is known that while the double bubble tubular film process gives better impact strength and more uniform shrinkage balance than the tenter process, yet it is relatively poor in film thickness uniformity. The film thickness uniformity of the PA 6 produced by the double bubble tubular film process was investigated.

The optimum stretching stress during the double bubble tubular film process exists. The bubble breaks over stress 130 MPa and bubble is unstable below stress 60 MPa. In the optimum condition, which is process temperature 310 °C and stretching ratio 3.2, stretched film uniformity was twice worse than non-stretched film one. The thickness uniformity of the film stretched in the optimum condition was better than that of the film stretched at higher process temperature and at lower stretching ratio. In the observations of the bubble sample through the polarizing plates, deformation pattern showed the equality of deformation. Thickness uniformity of non-stretched film significantly affects the thickness uniformity of biaxially oriented film.

Local stretching ratio, which varies along the film width, influences tensile modulus and tensile strength at break. In order to obtain the uniform physical properties of film, it is important to produce the film with uniform thickness. Film thickness uniformity can be improved when stretching stress is high and bubble stability is good. These factors are influenced by stretching temperature, stretching ratio and air velocity from air ring.

Deformation Behavior, Processability and Physical Properties for Biaxially Oriented Film of LLDPE

The bubble deformation behavior of double bubble tubular film (DBTF) of linear low density polyethylene (LLDPE) is experimentally analyzed. Also investigated is how the bubble deformation behavior of the stretched films are changed by stretching conditions, especially stretching temperature, and how the properties of stretched films are influenced by stretching conditions.

From the results, the optimum conditions required to obtain a stable bubble and good properties for the DBTF of LLDPE are indicated. The relationship between the DBTF and laboratory tenter stretched film (LTSF) is investigated in order to predict the processability and the properties of the DBTF by using the laboratory tenter biaxial stretcher. This method is not only more time efficient, but also reduces overall costs of developing the DBTF.

Easy Tear Film of Biaxially Oriented PA 6/MXD 6 Blend by Double Bubble Tubular Film Process

In the market, a film which adapted to environmental and barrier problems is desired. This report discusses the stretching stability and physical properties for biaxially oriented PA 6/ MXD 6 blending film produced by double bubble tubular film process. As MXD 6 blending ratio increased, the stretching stress decreased. Hydrogen bond is due to be suppressed by the steric hindrance of the MXD 6 resin. Blending film can be stretched stably and oxygen gas permeability is more excellent than PA 6. Further the film blended between 20 % and 40 % as MXD 6 blend ratio has the property of easy straight line cut. It is found that the plate-like cylinder structure was formed in the observation of TEM. However, thickness uniformity deteriorates when MXD 6 blending ratio exceeds 40 %. To improve the thickness uniformity, the influence of the kneading conditions was studied. When the melting point of MXD 6 decreased, the stretching stability deteriorated and mechanical properties drastically lowered. The excess reaction of the blending resins is not desirable. Stretchability, easy tear property and oxygen gas barrier property are maintained by following process conditions. In case of dry blending, MXD 6 30% is proper content. And in case of premixing, MXD 6 melting point keeps over 236°C. It was confirmed that there is the condition satisfying all properties. The blending film keeps the compatible performance of strength and easy tear property. Namely, the material and production technology of a film could solve environmental and barrier free problems.

Bowing Phenomenon in Double Bubble Tubular Film Processing for PA 6

This report is to discuss the bowing phenomenon and the sag elimination tension for biaxial oriented PA 6 film process, which consists of double bubble tubular film process and the thermosetting tentering.

The bowing phenomenon does not occur in the heat set of the triple bubble tubular process. However, there is a serious problem of the bubble stability when the sufficient thermosetting by the tubular process is carried out, so the heat set by the tenter process is required. The bowing phenomenon arises when the annealing is carried out by the tenter method. The bowing distortion becomes large when the annealing temperature is high and film relaxation ratio is large.

It is possible to reduce the bowing distortion when thermosetting is carried out in a two-step tenter process. The shrinkage stress of the stretched film was relaxed in the heat treatment during the second step whose temperature is higher than the first one. A two-step heat treatment was able to decrease the bowing distortion compared with the one-step heat treatment.

When the bowing phenomenon occurred, shrinkage percentage in hot water changes along the cross-direction of a film. The humidity expansion coefficient in the film which increases as the increasing shrinkage percentage in hot water is related to the molecular orientation. The sag also increased with increasing the bowing distortion. The bowing distortion and the sag elimination of tension have proportional connection.

Stretchability and Properties of LLDPE Blends for Biaxially Oriented Film

In order to improve the stretchability of linear low density polyethylene (LLDPE) for double bubble tubular film (DBTF), the blending of LLDPEs have been investigated. Three LLDPEs of varying densities were blended, and several films having different densities, molecular-weight distributions and composition distributions were produced. The stretchability and properties of these films were investigated and the relationship between the stretchability and the material properties were also discussed. The material properties of LLDPE which showed better stretchability were reported. Furthermore, the stretchability of LLDPE by using the laboratory tenter stretched film (LTSF) and the DBTF were compared. The prediction of the stretchability for the DBTF by using the LTSF was reported.

Stretchability and Properties of Various LLDPE for Biaxially Oriented Film

Stretchability and properties of linear low density polyethylene (LLDPE) blends for biaxially oriented film was investigated in the previous report [1]. That report focused on changing the film density by blending three different densities of LLDPE. The relationship among stretchability, film density and the composition distribution was explored. In this report, several different densities and melt flow indices (MFI) of LLDPE were examined. A film with a density of about 0.915 g/cm3 displayed the best stretchability, while films not less than 2 g/10 min MFI had poor stretchability. The most suitable composition distribution for stretching was reported. The properties of biaxially oriented films were also evaluated. Furthermore, the relationship between the laboratory tenter stretched film (LTSF) and the double bubble tubular film (DBTF) was investigated. There was a correlation between the density in film over 0.910 g/cm3 and the stretchability of the DBTF and LTSF.

Easy Tear Multilayer Film of Biaxially Oriented PA6/MXD6 by Double Bubble Tubular Film Process

In the market, a film which is adapted to environmental and barrier problems and easy tear property is desired. A previous report discussed easy tear PA6 film. This report discusses the film having not only easy tear, but also high barrier properties.

A biaxially oriented PA6/MXD6 blend film produced by double bubble tubular film process does possess gas barrier. So a multilayer film having high gas barrier layer and keeping easy tear cut has been studied. High gas barrier layer of high content MXD 6 in the center layer is added to PA6/MXD6 blend film in the outer layers.

When MXD6 blending ratio of PA6/MXD6 blending film layer is 30 %, the property of easy straight line cut is obtained. It is found that the plate-like cylinder structure was formed in the observation of TEM for PA6/MXD6 blend film.

The multilayer biaxially oriented film composed of PA6/MXD6 blend layer and MXD6 high content layer keeps high strength, easy tear property and high gas barrier. Namely, the material and production technology of a PA6 film could solve environmental and barrier problems.

Study on the Bleeding Mechanism of Slip Agents in a Polypropylene Film using Molecular Dynamics

The bleeding (internal transport) process of additives in a polypropylene film under atmospheric pressure was investigated. The experimental results were explained more precisely by a new model assuming the two-step transport between the amorphous and crystalline regions. The diffusion coefficient of a higher fatty acid such as behenic acid (docosanoic acid) in isotactic polypropylene film and that of higher fatty acid amides such as erucamaide (13-cis-docosenamide) in ethylene copolymerized polypropylene film were determined at 40 and 50°C respectively. The difference between the diffusion coefficients of three slip agents in a polypropylene film at 50°C was explained using a molecular dynamics simulation in which self-association of the slip agent molecules by hydrogen bonding was considered.

Acrylamide based molecularly imprinted polymer for detection of m-nitrophenol

Molecular imprinting has already proven to be one of the most promising artificial receptors that can lead to specific recognition at molecular level. In this work, molecular imprinting polymers (MIPs) were prepared from acrylamide (ACM) as functional monomer and m-nitrophenol as template respectively. Bis-acrylamide was used as cross-linker. Synthesis was carried out first by ultrasonication of the reaction mixture containing monomer, cross-linker and template in chloroform. Subsequently, the polymerization was conducted at high temperature catalyzed by initiator. Interaction between functional monomers and template was studied by using UV-Vis and 1H NMR spectroscopy. Removal and rebinding of template were monitored by using FTIR (ATR) and cross-polarization magic angle spinning (CP-MAS) 13C NMR spectrometer. The SEM micrograph showed absence of cavity in non-imprinted polymer (NIP), whereas definite cavities were observed in imprinted polymer (MIP). Maximum binding of m-nitrophenol by MIP was higher at lower template concentration, i.e., 0.54 mg/g of MIP at template concentration of 5 ppm as compared to 0.42 mg/g of MIP at template concentration of 10 ppm. Further, bis-acrylamide crosslinked MIP exhibited better binding ability as compared to that of ethylene glycol dimethacrylate cross linked MIP.

Multilayer Barrier Film of Biaxially Oriented PA6/EVOH by Double Bubble Tubular Film Process

In the market, a film adapted to environmental and barrier problems is desired. The previous report discussed easy tear and gas barrier PA6 film. This report discusses the multilayer PA6 film having high barrier EVOH layer.

A biaxially oriented PA6 film produced by double bubble tubular film process has high strength, but does not have enough gas barrier property compared with K-coated PA6. In the following a multilayer film with gas barrier layer is studied. A high gas barrier layer of EVOH is added to the center layer in the outer layers of PA6 films. The gas barrier ability increases with increasing the content of EVOH and decreasing ethylene content of EVOH, but at the same time the mechanical properties and processability get worse. From this point of view, it is found that the optimum content of EVOH is between 20% and 43%.

In a biaxially oriented multilayer film composed of PA6 layers and EVOH one keeps high strength and high gas barrier. The material and production technology of a PA6 film can solve environmental and barrier problems.