Supramolecular Chiral Assembly of Symmetric Molecules with an Extended Conjugated Core.

C3-symmetric molecules carrying a conjugated diacetylene (DA) core are found to self-assemble into well-defined supramolecular fibers with enhanced supramolecular chirality in both organic and aqueous solutions. The conjugated core affords these amphiphiles characteristic fluorescence properties, which can be quenched partially due to the aggregation. Integration of the C3-symmetry with the conjugation provides these novel molecules strong aggregation tendency through solvent-mediated π-π stacking with preferential supramolecular chirality, which is predominately related to steric hindrance from their dipeptide pendants. Highly uniform supramolecular fibers of P and M handedness with thickness consistent in the dimensions of individual C3 molecules are obtained. The increase of concentrations induces these fibers to wrap together to form supramolecular fibrous bundles. Topochemical polymerization of the DA moieties can transform these supramolecular fibers into stable covalent polymers. We therefore believe that self-assembly of these C3-symmetric molecules with extended conjugated DA cores provides new prospects for the construction of supramolecular helical fibers through enhanced π-π stacking and creates a convenient strategy to furnish covalent chiral polymers of hierarchical structures through supramolecular assembly.

Supramolecular Assembly of C3 -Peptides into Helical Fibers Stabilized through Dynamic Covalent Chemistry.

The supramolecular assembly of C3 -peptides carrying glycine-cysteine (Gly-Cys) dipeptide pendants into helical fibers is described. A Gly-Cys dipeptide sequence was selected to ensure the chirality, and at the same time, to provide a chance to crosslink the structure through oxidation of the thiol into dynamic covalent disulfide, and transfer supramolecular helical fibers into covalent ones. Supramolecular assembly in aprotic solvents affords long helical fibers with left-handedness, which can be stabilized through formation of disulfide. Transformation of supramolecular helical fibers into covalent ones was examined by NMR and FTIR spectroscopies as well as atom force microscopy.

OEGylated Cyclodextrins Responsive to Temperature, Redox, and Metal Ions.

The present work provides a versatile access for "smart" cyclodextrins (CDs) that are responsive to temperature, redox, and metal ions. These CDs are modified with oligoethylene glycols through thiol-ene click chemistry, which are inherently thermoresponsive in aqueous solutions. At the same time, their thermoresponsiveness is tunable through oxidation or metal ion chelation of thioether moieties. Significantly, these stimuli-responsive CDs retained strong inclusion abilities to guest dyes, and the inclusion complexation can be tuned by thermally induced phase transitions, oxidation, as well as metal chelation. The stimuli-responsive complexation with dyes allows to fabricate colorimetric/fluorescent sensors for temperature or for soft metal ions, such as Ag+ and Hg2+. With multiple responsiveness integrated in one material, these monodisperse CDs have formed a new class of stimuli-responsive macrocycles, which can reversibly encapsulate and release guest species through multiple switches.

Metal-Ion-Mediated Supramolecular Assembly of C3 -Peptides.

An investigation on a supramolecular assembly of C3 -molecules benzene-1,3,5-tricarboxamides carrying tetrapeptide Gly-Ala-Gly-Ala pendants promoted by hydrogen bonding and metal ion coordination is described. A Gly-Ala peptide sequence was selected as it is the most abundant repeating unit in silkworm silk, and known to form ß-sheets through efficient intermolecular hydrogen bonds. These C3 -peptides formed long helical fibers in solvents mainly owing to strong hydrogen bonding. However, in the presence of divalent metal ions, chirality of these helical fibers was enhanced through metal coordination and could be transformed into nanospheres with an excess amount of the ions. Different metal ions show different tendencies to mediate the supramolecular chirality, which can even be inverted according to coordination differences.

Photoinduced formation of an azobenzene-based CD-active supramolecular cyclic dimer.

A series of new photo-responsive amino acid-derived azobenzenedicarboxylic acid derivatives (S)-1 a-e were synthesized. Compound (S)-1 a in the trans form exhibited no circular dichroism (CD) signal in DMF under ambient conditions, whereas intense Cotton effects were observed upon UV irradiation, indicating the formation of a chiral supramolecular structure in the cis form. The CD signals disappeared when trifluoroacetic acid (TFA) was added to the solution. The ester counterpart [(S)-1 a'] showed no CD signal. Hydrogen bonding between the carboxy groups seemed necessary for constructing the supramolecular structure. The kinetic studies of cis to trans isomerization of (S)-1 a demonstrated that the formation of a chiral supramolecule enhances the stability of the cis-azobenzene structure. The ESI mass spectrum of stilbenedicarboxylic acid (S)-4, an analogue of (S)-1 b, confirmed the formation of a dimer. A theoretical CD study revealed that (S)-1 a in the cis form should be present as a cyclic chiral dimer.

Synthesis and helical structures of poly(ω-alkynamide)s having chiral side chains: effect of solvent on their screw-sense inversion.

New ω-alkynamides, (S)-HC≡CCH2CONHCH2CH(CH3)CH2CH3 (1) and (S)-HC≡CCH2CH2CONHCH(CH3)CH2CH2CH2CH2CH3 (2) were synthesized and polymerized with a rhodium catalyst in CHCl3 to obtain cis-stereoregular poly(ω-alkynamide)s (poly(1) and poly(2)). Polarimetric, CD, and IR spectroscopic studies revealed that in solution the polymers adopted predominantly one-handed helical structures stabilized by intramolecular hydrogen bonds between the pendent amide groups. This behavior was similar to that of the corresponding poly(N-alkynylamide) counterparts (poly(3) and poly(4)) reported previously, whereas the helical senses were opposite to each other. The helical structures of the poly(ω-alkynamide)s were stable upon heating similar to those of the poly(N-alkynylamide)s, but the solvent response was completely different. An increase in MeOH content in CHCl3/MeOH resulted in inversion of the predominant screw-sense for poly(1) and poly(2). Conversely, poly(3) was transformed into a random coil, and poly(4) maintained the predominant screw-sense irrespective of MeOH content. The solvent dependence of predominant screw-sense for poly(1) and poly(2) was reasonably explained by molecular orbital studies using the conductor-like screening model (COSMO).

Primer design for identifying economically important Liriomyza species (Diptera: Agromyzidae) by multiplex PCR.

Leafminer flies, especially, Liriomyza huidobrensis, Liriomyza sativae and Liriomyza trifolii, are quarantine species in many countries. Their morphological similarity makes identification difficult. To develop a rapid, reliable, sensitive and simple molecular identification method using multiplex PCR, we newly sequenced the mitochondrial cytochrome oxidase I (COI) genes of Liriomyza bryoniae, Liriomyza chinensis, L. huidobrensis, L. sativae, L. trifolii, Chromatomyia horticola and four parasitoid species. We aligned them with all the COI sequences of the leafminer flies found in the international DNA nucleotide sequence databases (DDBJ/EMBL/GenBank). We then designed species-specific primers to allow us to differentiate between L. bryoniae, L. chinensis, L. huidobrensis, L. sativae, and L. trifolii.

Indication of endoscopic retrograde cholangiography by noninvasive predictive factors of common bile duct stones before laparoscopic cholecystectomy: a prospective clinical study.

PURPOSE: To evaluate the reliability of a screening method in patients with common bile duct (CBD) stones before laparoscopic cholecystectomy (LC) based on predictive factors, and to determine the cases for which preoperative therapeutic endoscopic retrograde cholangiography (ERC) is indicated. MATERIALS AND METHODS: Alkaline phosphatase, total bilirubin, amylase, and dilation of CBD results were defined as predictive factors for CBD stones. In cases in which all these 4 factors were negative, preoperative ERC was omitted, and in cases in which 1 of the 4 factors was positive, ERC was performed before LC. RESULTS: A total of 323 patients (83.7%) in whom all 4 factors were negative, ERC was omitted. In all the 63 patients (16.3%) in whom 1 of the 4 factors was positive, ERC was performed. In 52 (82.5%) of them, CBD stones were present and in 43 of them, LC was performed after endoscopic choledocholithotomy. CONCLUSIONS: For cases in which any 1 of the 4 factors was positive before LC, it was strongly recommended to perform preoperative ERC.

[Efficacy of hepatic arterial infusion chemotherapy with cisplatin for advanced hepatocellular carcinoma].

BACKGROUND: Transcatheter arterial chemoembolization (TACE) was performed as the initial therapy for advanced hepatocellular carcinoma (HCC). However, no effective chemotherapy has been established for patients who did not respond to TACE, and for those the therapy was not suitable. Since 2004, transcatheter arterial infusion (TAI) chemotherapy using fine-powder cisplatin has been applied at our department to such cases mentioned before. This report described the therapeutic results of TAI therapy and presented a case of HCC accompanied by portal vein tumor thrombus (PVTT) for which the therapy was effective. PATIENTS AND METHODS: TAI was performed using cisplatin in 16 patients with inoperable advanced HCC between 2004 and 2010. Cisplatin was infused into the proper hepatic artery at a dose of 65 mg/m2 for 30 minutes. RESULTS: TAI was performed in each patient 1.8 times on average, ranging from 1 to 8 times. Therapeutic Effect 4 (TE4) was obtained in 1 case, TE3 in 2, TE2 in 1, and TE1 in 11 cases. The only severe adverse event rated as grade 3 or above during the study were nausea and anorexia reported in 6.3% of the patients, and adverse events rated as less than grade 2 were increased serum hepato-biliary enzyme levels in 68.8%, nausea in 68.8% of the patients. The overall 1-year survival rate was 31.2%, and the 50% survival period was 314 days. CONCLUSION: As a treatment option following the initial TACE therapy for advanced HCC, TAI using cisplatin can improve the prognosis of HCC.

Carcinoma of the ampulla of vater arising from the peribiliary gland.

The present paper reported a case of a carcinoma that probably developed from the peribiliary gland within the ampulla of Vater based on the histopathological findings of the resected specimens. A 49-year-old female became aware of epigastralgia and was diagnosis of stenosis of duodenal 2nd portion. There were no malignant findings on gastrointestinal endoscopy and computed thomography. Endoscopic retrograde cholangiopancreatography revealed no tumor in the main pancreatic duct or the common bile duct or ampulla of Vater. Pylorus preserving panctreaticoduodenectomy was performed with a diagnosis of duodenal stenosis of unknown cause. The histopathological findings revealed that a moderately to poorly differentiated adenocarcinoma originating near the peribiliary gland in the ampulla of Vater was extensively distributed in the submucosal layer of the duodenum. Based on these findings, a diagnosis of a carcinoma of the ampulla of Vater arising from the peribiliary gland was most likely suspected. Judging from the generally known development and extension of carcinoma of the ampulla of Vater, the current case appeared to be a very rare one.

[Two cases of advanced hepatocellular carcinoma with portal vein tumor thrombus responding to transcatheter arterial infusion chemotherapy using cisplatin].

We report two cases of advanced hepatocellular carcinoma( HCC) with a portal vein tumor thrombus (PVTT) responding to transcatheter arterial infusion chemotherapy (TAI) using cisplatin (CDDP). Case 1: A 65-year-old male patient was diagnosed with unresectable multiple HCCs. After 5 courses of transcatheter arterial chemoembolization (TACE), the tumor became markedly enlarged, and a PVTT (Vp2) and lymph node metastasis were noted. TAI was conducted as the second- line chemotherapy, and the liver tumor, PVTT, and lymph node metastasis shrank. The clinical response was rated as a partial response (PR). Case 2: A 72-year-old female patient was diagnosed with single HCC. After a course of TACE, the tumor became markedly enlarged and was accompanied by a PVTT (Vp4). TAI was performed as the second-line chemotherapy, and the liver tumor and PVTT significantly shrank. The clinical response was also rated as a PR. TAI using CDDP as the second-line chemotherapy for advanced HCC is a promising treatment likely to contribute to the improvement of the patient's prognosis.

Alternating ring-opening metathesis copolymerization of amino acid derived norbornene monomers carrying nonprotected carboxy and amino groups based on acid-base interaction.

Amino acid derived norbornene monomers having carboxy (1) and amino groups (2) were synthesized and subjected to ring-opening metathesis copolymerization with various feed ratios using the Grubbs second generation ruthenium catalyst. The M(n)'s of the copolymers ranged from 5300 to 9400 (M(w)/M(n) = 1.40-1.69). The monomer conversion and M(n) of the copolymer were maximized when the monomer feed ratio was 1:1. The monomer unit ratios in the copolymers were almost 1:1 at 10% conversion, irrespective of the feed ratios. The monomer reactivity ratios r(1) and r(2) were estimated to be 0.08 and 0.02, which confirmed that alternating copolymerization occurred. It is considered that alternating copolymerization is brought about by the acid-base interaction between the monomers and/or between the propagating polymer end and the incoming monomer.

Cellulose derivatives carrying triphenylamine (TPA) moieties: synthesis and electro-optical properties.

A novel ethyl cellulose derivative [poly(1)] that carries triphenylamine moieties is synthesized with a moderate number-average molecular weight up to 78,200 in 85% yield by the reaction of 4-(diphenylamino)benzoic acid with the residual hydroxy group of ethyl cellulose. Poly(1) is soluble in common organic solvents including toluene, CHCl3, CH2Cl2, and tetrahydrofuran while insoluble in hexane, diethyl ether, and methanol. The polymer emits blue-green fluorescence with quantum yields up to 65% in CHCl3 and displays unique solvatochromism. The cyclic voltammograms of poly(1) indicate that the polymer carrying TPA moieties is electrochemically redox active. The onset temperature of weight loss of the poly(1) is about 177 degrees C according to thermogravimetric analysis in air.

Synthesis and helical structure of poly(1-methylpropargyl ester)s with various side chains.

Optically active 1-methylpropargyl esters bearing various substituents were polymerized with [(nbd)Rh](+)[eta(6)-C(6)H(5)B(C(6)H(5))(3)](-) (nbd=norbornadiene) as a catalyst to afford the corresponding poly(1-methylpropargyl ester)s with moderate molecular weights in good yields. The polymers have a cis-stereoregular structure, which was determined by (1)H NMR spectroscopy. Large optical rotations and clear CD signals demonstrated that all these polymers take on a helical structure with a predominantly one-handed screw sense. The polymers exhibited large viscosity indices in the range 1.14-1.75. Chiral amplification was observed in R/S copolymerization. Conformational analysis revealed that the polymers form a tightly twisted helical structure with a dihedral angle of 70 degrees at the single bond of the main chain.

Synthesis and properties of DNA complexes containing 2,2,6,6-tetramethyl-1-piperidinoxy (TEMPO) moieties as organic radical battery materials.

We report here the first example of organic radical battery with DNA. Though there is a growing interest in DNA/cationic-lipid complexes as promising gene delivery vehicles, few efforts have been focused on the use of such complexes as advanced materials for organic optoelectronic applications. The present article describes how substitution of the sodium counter cation of DNA with cationic amphiphilic lipid(1-4) provided novel DNA-lipid complexes that contain TEMPO radicals, in which the actual mole ratio of phosphate to lipid was 1:0.84 to 1:0.16. All the TEMPO-containing DNA-lipid complexes displayed reversible two-stage charge/discharge processes, the discharge capacities of which were 40.5-60.0 A h kg(-1). In particular, the capacity of a DNA-lipid(3)-based cell reached 60.0 A h kg(-1), which corresponds to 192 % relative to its theoretical value for the single-electron one-stage process, indicating a two-electron process.

Preoperative assessment for feasibility of laparoscopic cholecystectomy using magnetic resonance cholangiography.

BACKGROUND/AIMS: We present the results of classification of magnetic resonance cholangiography (MRC) focusing upon visualization of cystic duct for preoperative laparoscopic cholecystectomy (LC), along with assessments of a possible correlation between MRC classification and feasibility of LC. METHODOLOGY: The study included a total of 663 patients who were diagnosed as cholelithiasis. MRC were classified into four types: Type A; entire biliary tract was visualized (+), Type B; cystic duct (+) but gallbladder was not(-), Type C; gallbladder (+), cystic duct (-), and Type D; gallbladder (-), cystic duct (-). The feasibility of LC was assessed using the following two variables: 1) percentages of cases in which LC was changed to open cholecystectomy (OC) and 2) operating time. The results were compared in respect of the relationship with the MRC classification. RESULTS: MRC were classified as follows: Type A (58.4%), Type B (15.2%), Type C (19.3%) and Type D (7.1%). A total of 124 patients (18.7%) had chronic cholecystitis, and a strong correlation with MRC type was noted (p<0.0001). In 46 patients (7.5%), the surgical procedure was changed from LC to OC. The percentages of cases in which LC was changed to OC was significantly higher for Type C and Type D (p<0.0001), so these two groups demonstrated prolonged operating time. CONCLUSIONS: Our MRC classification based on the visualization of cystic duct can reflect the feasibility of LC, and LC may be less feasible tin Type C, and in particular Type D patients.

Synthesis and charge/discharge properties of polyacetylenes carrying 2,2,6,6-tetramethyl-1-piperidinoxy radicals.

The 2,2,6,6-tetramethyl-1-piperidinoxy (TEMPO)-containing acetylenic monomers HC[triple bond]CC(6)H(3)-p,m-(CONH-4-TEMPO)(2) (1), HC[triple bond]CC(6)H(3)-p,m-(COO-4-TEMPO)(2) (2), (S,S,S,S)-HC[triple bond]CC(6)H(3)-p,m-[CO-NHCH{COO-(4-TEMPO)}CH(2)COO-(4-TEMPO)](2) (3), (S,S)-HC[triple bond]CC(6)H(4)CO-NHCH{COO-(4-TEMPO)}CH(2)COO-(4-TEMPO) (4), HC[triple bond]CC(6)H(4)-p-OCO-4-TEMPO (5), HC[triple bond]CCH(2)C(CH(3))(CH(2)OCO-4-TEMPO)(2) (6), HC[triple bond]CCH(2)NHCO-4-TEMPO (7), and HC[triple bond]CCH(2)OCO-4-TEMPO (8) were polymerized to afford novel polymers containing the TEMPO radical at high densities. Monomers 1, 3-6, and 8 provided polymers with average molecular weights of 10 000-136 500 in 62-99 % yield in the presence of a rhodium catalyst, whereas monomers 2 and 7 gave insoluble polymers in 100 % yield. The formed polymers were thermally stable up to approximately 274 degrees C according to thermogravimetric analysis (TGA). All the TEMPO-containing polymers demonstrated reversible charge/discharge processes, whose discharge capacities were 21.3-108 A h kg(-1). In particular, the capacity of poly(1)-, poly(4)-, and poly(5)-based cells reached 108, 96.3, and 89.3 A h kg(-1), respectively, which practically coincided with their theoretical values.

Synthesis and extremely high gas permeability of polyacetylenes containing polymethylated indan/tetrahydronaphthalene moieties.

Polymethylated poly(diphenylacetylene) derivatives, a new category of substituted polyacetylenes, were successfully synthesized, and proved to show extremely high gas permeability.

[Transradial approach for transcatheter arterial chemoembolization in patients with unresectable and recurrent hepatocellular carcinoma--a comparison with a conventional transfemoral approach].

We evaluated a clinical usefulness and safety of transradial approach for transcatheter arterial chemoembolization (TAE) in patients with unresectable and recurrent hepatocellular carcinoma (HCC) compared with that of conventional transfemoral approach. The two groups (radial group; n=385, 1999.7-2007.3, femoral group; n=150, 1997.4-1999.6) of cases were retrospectively compared with regard to the successful rate of angiography, TAE, interventional time, Lipiodol retention pattern and complications. Hepatic angiography and TAE were completed in 379 (98.4%) of 385 cases in the radial group. There was no inter-group difference of interventional time. Minor complications (dull pain or numbness of puncture site) occurred in 29 (7.6%) patients in the radial group. Transradial approach has some advantages as follows: (1) No time will be required to stop breeding after removal of sheath. (2) The patient may freely walk after the examination. TAE by our new transradial approach for HCC was found to have a therapeutic efficacy with lower complications comparable to that of conventional transfemoral approach.

Useful predictive factors of common bile duct stones prior to laparoscopic cholecystectomy for gallstones.

BACKGROUND/AIMS: The aim of this study was to determine useful predictive factors of common bile duct stones (CBDs) as diagnosed by endoscopic retrograde cholangiopancreatography (ERCP) in patients who underwent laparoscopic cholecystectomy (LC) for gallstones. METHODOLOGY: A total of 510 patients underwent ERCP prior to LC. Also reviewed in each were clinical data, laboratory data, and ultrasonographic findings. Data were evaluated by uni- and multivariate analysis to determine which of the useful predictive factors thus far reported might be in the concurrence of CBDs. RESULTS: Univariate analysis identified jaundice, pancreatitis, ALT, total bilirubin, alkaline phosphatase, amylase, and CBD dilatation at ultrasonography as predictors. Multivariate analysis subsequently identified alkaline phosphatase (p<0.0001), total bilirubin (p=0.0008), amylase (p=0.0009), and CBD dilatation at ultrasonography (p=0.0012) as independent predictive factors of CBDs. The estimates for the detection of CBDs, when the indication of ERCP is determined on the basis of the four predictive factors, were found to be as follows: sensitivity 97.6%, positive predictive value 78.6%, and positive accuracy 95.3%. CONCLUSIONS: It is advisable to ascertain by preoperative ERCP whether there might be any CBDs in patients about to undergo an LC for treatment of cholelithiasis insofar as the patient has one or more of these factors. It is concluded that an LC may be performed by omitting the prior ERCP, conversely, on patients devoid of all of these factors.