Proton Conduction at High Temperature in High-Symmetry Hydrogen-Bonded Molecular Crystals of RuIII Complexes with Six Imidazole-Imidazolate Ligands.

Invited for the cover of this issue is mainly the group of Makoto Tadokoro and co-workers at Tokyo University of Science. Other co-workers are Masaki Itoh, Ryota Nishimura, Kensuke Sekiguchi (TUS students), Dr. Norihisa Hoshino (Tohoku Univ.), Dr. Hajime Kamebuchi (Nihon Univ.), Dr. Jun Miyazaki (Tokyo Denki Univ.), Prof. Motohiro Mizuno (Kanazawa Univ.) and Prof. Tomoyuki Akutagawa (Tohoku Univ.). The image depicts on two mechanisms of proton transport rotations of the proton-conductive starburst molecule [RuIII (HIm)3 (Im)3 ]. Read the full text of the article at 10.1002/chem.202201397.

Proton Conduction at High Temperature in High-Symmetry Hydrogen-Bonded Molecular Crystals of RuIII Complexes with Six Imidazole-Imidazolate Ligands.

A new H-bonded crystal [RuIII (Him)3 (Im)3 ] with three imidazole (Him) and three imidazolate (Im- ) groups was prepared to obtain a higher-temperature proton conductor than a Nafion membrane with water driving. The crystal is constructed by complementary N-H⋅⋅⋅N H-bonds between the RuIII complexes and has a rare Icy-c* cubic network topology with a twofold interpenetration without crystal anisotropy. The crystals show a proton conductivity of 3.08×10-5  S cm-1 at 450 K and a faster conductivity than those formed by only HIms. The high proton conductivity is attributed to not only molecular rotations and hopping motions of HIm frameworks that are activated at ∼113 K, but also isotropic whole-molecule rotation of [RuIII (Him)3 (Im)3 ] at temperatures greater than 420 K. The latter rotation was confirmed by solid-state 2 H NMR spectroscopy; probable proton conduction routes were predicted and theoretically considered.

Possible Tomonaga-Luttinger spin liquid state in the spin-1/2 inequilateral diamond-chain compound K3Cu3AlO2(SO4)4.

K3Cu3AlO2(SO4)4 is a highly one-dimensional spin-1/2 inequilateral diamond-chain antiferromagnet. Spinon continuum and spin-singlet dimer excitations are observed in the inelastic neutron scattering spectra, which is in excellent agreement with a theoretical prediction: a dimer-monomer composite structure, where the dimer is caused by strong antiferromagnetic (AFM) coupling and the monomer forms an almost isolated quantum AFM chain controlling low-energy excitations. Moreover, muon spin rotation/relaxation spectroscopy shows no long-range ordering down to 90 mK, which is roughly three orders of magnitude lower than the exchange interaction of the quantum AFM chain. K3Cu3AlO2(SO4)4 is, thus, regarded as a compound that exhibits a Tomonaga-Luttinger spin liquid behavior at low temperatures close to the ground state.

Synchronized Collective Proton-Assisted Electron Transfer in Solid State by Hydrogen-Bonding Ru(II)/Ru(III) Mixed-Valence Molecular Crystals.

A proton-coupled electron transfer (PCET) reaction was widely studied with isolated organic molecules and metal complexes in solution in view of the biological catalytic reaction, while studying this reaction in the crystalline or solid-state phase, which has a novel example, would give insight into the rather internal environment of proteins without solvation and a creation of new molecular materials. We tried to crystallize a hydrogen-bonded (H-bonded) coordination polymer with one-dimensional nanoporous channels, formed from redox-active RuIII complexes, [RuIII(Hbim)3] (Hbim- = 2,2'-biimidazolate monoanion). As a result, a synchronized collective PCET phenomenon was observed for the molecular nanoporous crystal by novel solid-state cyclic voltammetry (CV), which could be measured by only setting some crystals on the electrode surface. The nanoporous crystals, {[RuIII(Hbim)3]}n (1), are simultaneously induced to a synchronized collective RuIIRuIII mixed-valence state, {RuIIRuIII}n, with alternating arrays of RuII and RuIII complexes by PCET in a way of the reductive state of {RuIIRuII}n. Further, a new crystal with {RuIIRuIII}n, {[RuII(H2bim)(Hbim)2][RuIII(bim) (Hbim)2][K(MeOBz)6]}n (2), was also prepared, and the solid-state CV revealed the same electrochemical behavior of {RuIIRuIII}n with 1. The single crystal with {RuIIRuIII}n of 2 was unusually a semiconductor with 5.12 × 10-6 S/cm conductivity at 298 K by an impedance method (8.01 × 10-6 S/cm by a direct-current method at 277 K). Thus, an unprecedented electron-hopping conductor driven by a low-barrier proton transfer through a PCET mechanism (Ea = 0.30 eV) was realized in the H-bonding molecular crystal with {RuIIRuIII}n. Such studies on a PCET reaction in the crystalline state is not only worthwhile as a model of essential biological reactions without solvation, but also proposed to a new design of molecular materials to occur an electron transfer by using an intermolecular H-bond.

Copper-catalyzed α-methylenation of benzylpyridines using dimethylacetamide as one-carbon source.

The direct α-methylenation of benzylpyridines was achieved using N,N-dimethylacetamide (DMA) as a one-carbon source under copper catalysis. An intermediary species was detected at an early stage, and a possible mechanism was proposed. Additionally, α-oxygenation and dimerization of benzylpyridines could also be performed efficiently.

Rhodium-catalyzed decarboxylative and dehydrogenative coupling of maleic acids with alkynes and alkenes.

The dehydrogenative coupling of maleic acids with alkynes proceeds smoothly accompanied by decarboxylation under rhodium catalysis to produce variously substituted α-pyrone derivatives. The catalyst system is also applicable to the coupling with 1,3-diynes and alkenes.

Ruthenium-catalyzed ortho-alkenylation of phenylphosphine oxides through regio- and stereoselective alkyne insertion into C-H bonds.

Direct ortho-substitution took place efficiently upon treatment of tri-, di-, and monoarylphosphine oxides with internal alkynes in the presence of a ruthenium catalyst to produce (o-alkenylphenyl)phosphine oxides regio- and stereoselectively. Chemoselective reduction of a product gave the corresponding (o-alkenylphenyl)phosphine, which may be useful as a ligand for transition metals.

Rhodium- and iridium-catalyzed dehydrogenative cyclization through double C-H bond cleavages to produce fluorene derivatives.

The rhodium-catalyzed cyclization of a series of 2,2-diarylalkanoic acids in the presence of copper acetate as an oxidant smoothly proceeded through double C-H bond cleavages and subsequent decarboxylation to produce the corresponding fluorene derivatives. The direct cyclization of triarylmethanols also took place efficiently by using an iridium catalyst in place of the rhodium, while the hydroxy function was still intact.

[Surgery for unruptured middle cerebral artery aneurysm].

Although a large number of patients with unruptured middle cerebral artery (MCA) aneurysms (AN) have been treated by surgical clipping in Japan, there has yet been no comprehensive study investigating the surgical risks based on a quantitative evaluation of the extensive existing body of patient records. This systematic review was conducted to determine morbidity of the procedure by performing a meta-analysis of the literature. The authors used a PubMed and J-stage search from 2000 to 2011 for studies containing the surgical clipping of the unruptured MCA AN. There were 21 articles, containing a total 1,323 cases of unruptured AN with morbidity specifically located in the MCA. 54 cases indicated significant neurological deficits for a morbidity rate of 4.1% (95% CI; 3.0-5.1). A limited number of studies disclosed an incremental increase in morbidity with the size of the aneurysm. Smaller MCA AN (7±3 mm) presented a lower morbidity of 1.48%, whereas giant MCA AN (>25 mm) corresponded with a higher morbidity of 27.8%. Factors consistently associated with high morbidity included incorporated MCA branches, plaque at the neck of the AN, an unclippable configuration, and M1 superior wall AN. Complex aneurysms required a wide array of intracranial bypass procedures, yielding morbidity of 23.4% (95% CI; 20.9-25.9). This is the first systematic review and quantitative meta-analysis of the surgical complications related to unruptured MCA AN.

A cis-complex of NB-2/contactin-5 with amyloid precursor-like protein 1 is localized on the presynaptic membrane.

NB-2/contactin-5 plays an important role in synapse formation in the developing auditory system of rodents. In this study, to further elucidate the molecular role of NB-2 in synapse formation, we examined the interaction between NB-2 and amyloid precursor-like protein 1 (APLP1), as well as their possible co-localization at the synapse. Pull-down assays and cell surface binding assays demonstrated that NB-2 interacts with APLP1. Furthermore, the protein expression profile of APLP1 in western blots was similar to that of NB-2, and localization of APLP1 mRNA partially overlapped that of NB-2 mRNA. In cultured hippocampal neurons, immunofluorescence signals for both NB-2 and APLP1 overlapped with synapsin, a presynaptic marker. Biochemical analysis showed that both NB-2 and APLP1 were enriched in the presynaptic fraction. These results indicate that NB-2 forms a cis-complex with APLP1 on the presynaptic membrane.

Continuous and high-dose cytarabine combined chemotherapy in children with down syndrome and acute myeloid leukemia: Report from the Japanese children's cancer and leukemia study group (JCCLSG) AML 9805 down study.

BACKGROUND: The aim of the JCCLSG AML 9805 Down study was to evaluate the effect of continuous and high-dose cytarabine combined chemotherapy on the survival outcome of acute myeloid leukemia (AML) with Down syndrome (DS). PROCEDURE: From May 1998 to December 2006, DS patients with newly diagnosed AML were enrolled. Remission induction therapy consisted of two courses of pirarubicin, vincristine, and continuous-dose cytarabine (AVC1). The patients who achieved complete remission (CR) after two courses of AVC1 were subsequently treated with mitoxantrone and continuous-dose cytarabine (MC), etoposide and high-dose cytarabine (EC) and pirarubicin, vincristine, and continuous-dose cytarabine (AVC2). RESULTS: Twenty-four patients were enrolled. All patients were younger than 4 years and diagnosed as having acute megakaryoblastic leukemia. Twenty-one patients achieved CR. Three patients died during remission induction therapy due to serious infection. No toxic deaths were observed during remission. All but one patient maintained CR without serious complications. The 5-year overall and event-free survivals were 87.5% ± 6.8% and 83.1% ± 7.7%, respectively. CONCLUSIONS: Continuous and high-dose cytarabine combined chemotherapy with reduced intensity would be effective in DS children with AML.

Analysis three abnormal Protein S genes in a patient with pulmonary embolism.

A protein S (PS) abnormality is a hereditary risk factor for thromboembolism. A 33-year-old female had a left deep vein thrombosis (DVT) and mild pulmonary embolism (PE). Her PS antigen level was 34.7% and the activity level was less than 10%. Genetic analysis identified three missense mutations in PS: the D38Y mutation in exon 3, and the T589I mutation and P626L mutations in exon 15. The D38Y mutation has not been reported previously. An analysis of the patient's family revealed that all members of the family had some PS gene mutation. The D38Y and T589I mutations were both in same allele, the P626L mutation was in another allele. The expression of PS mutations in COS-7 cells revealed that PS activity and antigen were markedly decreased in the D38Y mutation but not in the T589I mutation. The expression of the P626L mutation in baby hamster kidney (BHK) cells showed the PS activity and antigen to be markedly decreased in comparison to the wild type.

Collection by a simple bag method and the function of granulocytes in granulocyte transfusion.

Granulocyte transfusion is effective for treating some intractable infections. We have recently developed a simple bag method for collecting granulocytes without using apheresis. A recombinant human granulocyte colony-stimulating factor (G-CSF) (50, 100, 200, and 400 microg nartograstim) was administered to 5 healthy male adult volunteers. The quantity and quality of the collected granulocytes were evaluated. The G-CSF dose proportionally increased the collected neutrophil count. The count of collected neutrophils correlated strongly with the count before collection (r2 = 0.684; P < .001). The neutrophil counts collected from 200 mL whole blood were 0.90 x 10(9), 1.68 x 10(9), 2.40 x 10(9), and 2.99 x 10(9) at 50, 100, 200, and 400 microg G-CSF, respectively. There was no significant difference in neutrophil counts between the 200-microg and 400-microg doses. doses. Concerning granulocyte functions, active oxygen production and phagocytic capacity were not affected by irradiation with 15 Gy. Transient arthralgia occurred in 2 subjects. A single administration of 200 microg G-CSF enabled the collection of large quantities of granulocytes by the bag method. We consider that the collection of granulocytes by the bag method from 400 mL of whole blood drawn twice can theoretically provide 3 x 10(8)/kg of granulocytes for treating children weighing less than 30 kg.

Combined effects of cyclooxygenase-1 and cyclooxygenase-2 selective inhibitors on intestinal tumorigenesis in adenomatous polyposis coli gene knockout mice.

As with cyclooxygenase (COX)-2, genetic disruption of COX-1 gene or pharmacologic inhibition of its activity has been shown to decrease the number of intestinal polyps in Apc gene-deficient mice. The present study was designed to investigate the combined effects of COX-1 and COX-2 selective inhibitors on spontaneous polyp formation in APC1309 female mice. The animals were treated with 300 or 600 ppm mofezolac (a COX-1 selective inhibitor) alone, 200 or 400 ppm nimesulide (a COX-2 selective inhibitor) alone, 300 ppm mofezolac plus 200 ppm nimesulide, 600 ppm mofezolac plus 400 ppm nimesulide, or 10 ppm indomethacin (a dual-COX inhibitor) in the diet from 7 weeks of age for 4 weeks. Percentage inhibition of polyp area in the intestine was 17% with 600 ppm mofezolac alone and 25% with 400 ppm nimesulide alone, their sum of 42% being almost equal to the 37% observed for the combination treatment. Administration of 300 ppm mofezolac plus 200 ppm nimesulide also significantly decreased polyp area in the intestine by 30%. Moreover, the numbers of polyps more than 2.5 mm in diameter were markedly decreased by combined treatment of both COX inhibitors. With 10 ppm indomethacin, the dual inhibitor, polyp area was also clearly reduced by 46%. Our results indicate that COX-1 and COX-2 may to some extent contribute to polyp formation independently and inhibitor combination treatment thus has particular potential for chemoprevention of colon carcinogenesis.

Concomitant suppression of hyperlipidemia and intestinal polyp formation in Apc-deficient mice by peroxisome proliferator-activated receptor ligands.

Epidemiological studies have shown a positive association of colon cancer with hyperlipidemia. Furthermore, signaling generated by peroxisome proliferator-activated receptor (PPAR) alpha and gamma ligands, suggested to be candidate tumor preventive agents, has been shown to lower serum triglyceride levels. In the present study, we assessed hyperlipidemia in Apc-deficient mice, model animals for human familial adenomatous polyposis, and examined the effects of pioglitazone and bezafibrate, respectively, PPARgamma and PPARalpha agonists, on both hyperlipidemia and intestinal polyposis. Serum lipid levels in Apc(1309) mice and Min mice from 6 to 15 weeks of age were measured. Although serum levels of triglyceride and cholesterol were low in both Apc(1309) and wild-type mice at 6 weeks, triglycerides were elevated 10-fold in Apc(1309) mice by the age of 12 weeks but not in their wild-type counterparts. Cholesterol was also increased significantly, and marked centrilobular-restricted steatosis was observed in the livers of aged Apc(1309) mice. Similar findings were observed for Min mice at 15 weeks of age. Moreover, lipoprotein lipase mRNA levels in the liver and small intestine of Apc(1309) and Min mice were demonstrated to be lower than those in wild-type mice. Treatment of Apc(1309) mice with 100 and 200 ppm pioglitazone or bezafibrate for 6 weeks from 6 weeks of age caused dose-dependent reduction in serum triglycerides and cholesterol, along with reduction in the numbers of intestinal polyps to 67% of the control value. The present study clearly demonstrated a hyperlipidemic state in Apc gene-deficient mice and a potential of PPARalpha and PPARgamma ligands to suppress both hyperlipidemia and polyp formation. Hyperlipidemia in these mice may thus be associated with their intestinal lesion development.

Combined effects of prostaglandin E receptor subtype EP1 and subtype EP4 antagonists on intestinal tumorigenesis in adenomatous polyposis coli gene knockout mice.

Previous studies have shown that prostaglandin E(2) (PGE(2)) is involved in intestinal carcinogenesis through its binding to the PGE(2) receptor subtypes EP(1) and EP(4) and activation of downstream pathways. ONO-8711 and ONO-AE2-227, prostaglandin E receptor subtype EP(1)- and EP(4)-selective antagonists, respectively, are known to suppress formation of intestinal polyps in adenomatous polyposis coli gene-deficient mice. The present study was designed to investigate the combined effects of EP(1) and EP(4) antagonists on spontaneous polyp formation in APC1309 mice in order to determine the contribution of each receptor to intestinal tumorigenesis. APC1309 mice were treated with 400 ppm of ONO-8711 alone, 400 ppm of ONO-AE2-227 alone or both in combination in the diet for 6 weeks. The mean area of polyps found in the intestine, calculated as the longer diameter x the shorter diameter x pi, was reduced by 12%, 43% (P < 0.01) and 56% (P < 0.01) of the mean control value (8.8 mm(2)) in the ONO-8711 alone, ONO-AE2-227 alone and combination treatment groups, respectively, suggesting clear additive effects of the combination. The same additive tendency for suppression was also observed with respect to the numbers of polyps in the intestine. Polyp size reduction was more remarkable with the EP(4) antagonist, while the number reduction was more pronounced with the EP(1) antagonist. Our results indicate that EP(1) and EP(4) may have separate intrinsic roles and, to some extent, contribute to polyp formation independently. Thus, combination treatment has potential for the chemoprevention of colon carcinogenesis.

Inhibitory effects of mofezolac, a cyclooxygenase-1 selective inhibitor, on intestinal carcinogenesis.

Cyclooxygenase (COX)-2, one enzyme isoform responsible for producing prostanoids from arachidonic acid, contributes to colon carcinogenesis. Recently, genetic disruption of COX-1, the other isoform, was shown to decrease the number of intestinal polyps and prostaglandin E(2) levels in intestinal mucosa, like the case with COX-2 gene disruption, in Min mice. We therefore investigated whether a COX-1 selective inhibitor, mofezolac, suppresses intestinal carcinogenesis in rodents. F344 male rats, receiving azoxymethane (AOM, 15 mg/kg body wt) s.c. injections at 5 and 6 weeks of age, were fed a diet containing 600 or 1200 p.p.m. mofezolac for 4 weeks. The number of aberrant crypt foci (ACFs) per rat and the bromodeoxyuridine labeling index of the crypt epithelium were dose-dependently decreased by administration of mofezolac, the value for the former at 1200 p.p.m. being 60% of control value. When Apc gene knockout mice (APC1309 mice) were given 600 or 1200 p.p.m. mofezolac in their diet for 8 weeks, the numbers of intestinal polyps were also dose-dependently decreased, with reduction to 59% of that in the control diet group at the higher dose. Nimesulide, a COX-2 selective inhibitor used as positive control, showed similar suppressive effects on the development of ACFs in AOM-treated rats and polyps in Apc gene knockout mice. The data indicate that both COX-1 and COX-2 can contribute to intestinal tumorigenesis.