Sustained remission of Cronkhite-Canada syndrome after corticosteroid and mesalazine treatment: A case report.

BACKGROUND: Cronkhite-Canada syndrome (CCS) is a rare disease of unknown etiology. The optimal treatment for CCS remains unknown. Treatment with corticosteroids is considered the mainstay treatment because of its high efficacy, but the therapeutic strategy for steroid-resistant CCS is not yet established. CASE SUMMARY: This is the case of an 81-year-old woman who was diagnosed with CCS. Given her severe diarrhea, nausea, vomiting, and hypoproteinemia, hormone therapy (40 mg/d) was administered, and the symptoms improved within 1 wk. After 3 mo, the patient had no obvious symptoms. The polyps were significantly reduced on review gastroscopy and colonoscopy, thus hormone reduction gradually began. The hormone level was maintained at 10 mg/d after 6 mo. Despite the age of the patient and the side effects of hormones, the patient had no obvious discomfort. However, hormone drugs were discontinued, and mesalazine was administered orally at 3 g/d. The patient's symptoms continued to improve after a follow-up of 5 years. CONCLUSION: Corticosteroids and mesalazine are potential treatment options for CCS.

Luminescent triarylboron-functionalized zinc carboxylate metal-organic framework.

A luminescent triarylboron ligand functionalized with three carboxylic groups has been synthesized and fully characterized. Its use in boron-containing metal-organic frameworks (B-MOFs) has been demonstrated by the synthesis and isolation of a Zn(II)B-MOF compound (B-MOF-1). The crystals of B-MOF-1 belong to the cubic space group F432 with 8-fold interpenetrated networks and ∼21% void space. B-MOF-1 exhibits blue fluorescence and is capable of modest gas sorption of N(2), argon, and CO(2).

{Bis[2-(diphenyl-phosphan-yl)eth-yl]phenyl-phosphane-κP,P',P''}[(Z)-8-mesityl-cyclo-oct-4-en-1-yl]platinum(II) tetra-fluorido-borate dichloro-methane disolvate.

In the title ionic compound, [Pt(C(17)H(23))(C(34)H(33)P(3))](BF(4))·2CH(2)Cl(2), the Pt(II) atom adopts a square-planar coordination geometry with the large (Z)-8-mesityl-cyclo-oct-4-en-1-yl group occupying the fourth coordination site. The (triphos)Pt moiety and the mesityl group are attached to the cyclo-oct-4-ene motif at the 1- and 8-position in a syn configuration. The (BF(4))(-) anion and one of the dichloromethane solvate molecules each are disordered over two sets of sites.

Explorations of new second-order nonlinear optical materials in the K(I)-M(II)-I(V)-O systems.

Explorations of new second-order nonlinear optical (NLO) materials in the K(I)-M(II) -I(V)-O systems led to four novel mixed metal iodates, namely, K(2)M(IO(3))(4)(H(2)O)(2) (M = Mn, Co, Zn, Mg). The four compounds are isostructural and crystallize in space group I2 which is in the chiral and polar crystal class 2. Their structure features zero-dimensional {M(IO(3))(4)(H(2)O)(2)}(2-) anions that are separated by K(+) cations. The M(II) centers are ligated by two aqua ligands in trans fashion and four monodentate iodate anions. The K(+) cation is eight-coordinated by two iodate anions in bidentate chelating fashion and four other iodates in a unidentate fashion. Second harmonic generation (SHG) measurements indicate that K(2)Zn(IO(3))(4)(H(2)O)(2) and K(2)Mg(IO(3))(4)(H(2)O)(2) display moderate SHG responses that are approximately 2.3 and 1.4 times of KH(2)PO(4) (KDP), respectively, and they are also phase-matchable. The SHG response of K(2)Co(IO(3))(4)(H(2)O)(2) is much weaker (about 0.3 x KDP), and no obvious SHG signal was detected for K(2)Mn(IO(3))(4)(H(2)O)(2). Results of optical property calculations for the Zn and Mg phases revealed SHG responses of approximately 5.3 and 4.7 times of KDP, respectively, the order of Zn > Mg is in good agreement with the experiment data.

Berberine mitigates high glucose-induced podocyte apoptosis by modulating autophagy via the mTOR/P70S6K/4EBP1 pathway.

AIMS: This study aimed to investigate the characteristics and mechanism of autophagy on podocyte apoptosis under high glucose (HG) conditions and further explore the effect of berberine on podocyte autophagy, apoptosis and the potential mechanism. MATERIALS AND METHODS: The levels of LC3II/I in podocytes stimulated with HG were detected at 0, 2, 4, 8, 12, 24, 36 and 48 h by western blotting. CCK-8 was used to detect the viability of podocytes. The level of autophagy was detected by western blotting, transmission electron microscopy and immunofluorescence. Podocyte apoptosis was analysed by using Hoechst staining, western blotting, annexin V/propidium iodide dual staining, and confocal microscopy. Then, podocytes were transfected with siRNA to silence mTOR, and the expression levels of proteins and mRNA involved in the mTOR/P70S6K/4EBP1 pathway were further investigated by western blotting and qRT-PCR. KEY FINDINGS: In this study, we found significantly reduced LC3II/LC3I and increased p62 in podocytes stimulated with HG for 24 h, and the level of autophagy reached a minimum at 24 h. Berberine restored podocyte viability and significantly attenuated HG-mediated inhibition of autophagy, as evidenced by the increased expression of LC3II/LC3I, the number of autophagosomes and the inhibition of p62. Moreover, berberine counteracted HG-induced podocyte apoptosis and injury, which was negatively correlated with the autophagy effect. Notably, silencing mTOR with siRNA augmented the inhibition of P70S6k and 4EBP1 phosphorylation, which was similar to the effect of berberine. SIGNIFICANCE: Berberine activates podocyte autophagy by inhibiting the mTOR/P70S6K/4EBP1 signaling pathway, thereby alleviating podocyte apoptosis.

Unconventional Pyridyl Ligand Inclusion within a Flexible Metal-Organic Framework Bearing an N,N'-Diethylformamide (DEF)-Solvated Cd5 Cluster Secondary Building Unit.

A cationic three-dimensional (3D) metal-organic framework (MOF) sustained by an N,N'-diethylformamide (DEF)-solvated zigzag-shaped Cd5 cluster secondary building unit (SBU), [Et2 NH2 ]2 [Cd5 (BTB)4 (DEF)2 ] ⋅ 4.75DEF (1 a, H3 BTB=benzene-1,3,5-tribenzoic acid) shows flexible framework behavior and undergoes solvate exchange with CHCl3 to yield [Et2 NH2 ]2 [Cd5 (BTB)4 (DEF)2 ] ⋅ xCHCl3 (1 b) accompanied by changes to pore sizes and shapes. Unexpectedly, the DEF solvates coordinated to the central Cd2+ could not be replaced by strongly donor pyridyl and dipyridyl ligands. Additionally, more electron-deficient pyridyls preferentially coordinated to the flanking Cd2+ of the Cd5 SBU, as exemplified by [Et2 NH2 ]2 [Cd5 (BTB)4 (DEF)2 (PyCHO)2 ] ⋅ xSol (2 a, PyCHO=4-pyridinealdehyde) and [Et2 NH2 ]2 [Cd5 (BTB)4 (DEF)2 (PyAc)2 ] ⋅ xSol (2 b, PyAc=4-acetylpyridine). Density functional theory (DFT) calculations were used to understand these counterintuitive observations.

Switchable ambient-temperature singlet-triplet dual emission in nonconjugated donor-acceptor triarylboron-Pt(II) complexes.

A triarylboron compound Si-BNPA (1) containing a BMes(2) acceptor and an N-(2'-pyridyl)-7-azaindolyl (NPA) donor linked by a tetrahedral silane group has been synthesised. This molecule displays unusual white singlet-triplet dual emission at 77 K, with an exceptionally long phosphorescent decay time (2.2 s). Fluoride titration experiments established that the singlet and triplet emission peaks are due to acceptor-based Mes-->B charge transfer and donor-based 3pi-->pi* transitions, respectively. This dual emission was found to be persistent and observable at ambient temperature in its Pt(II) complex [Pt(N,N-Si-BNPA)Ph2] (2a). Furthermore, 2a was found to undergo intramolecular "roll-over" C-H activation to produce the N,C-chelate complex [Pt(N,C-Si-BNPA)(SMe2)Ph] (2b). This compound also displays ambient temperature singlet-triplet dual emission, but with a much greater phosphorescent efficiency than 2a due to the formation of a more stable chelate ring. Addition of fluoride was found to have little impact on the phosphorescent emission of 2a, but resulted in a large enhancement of the phosphorescent emission intensity of 2b. To establish the impact of donor-acceptor geometry on this singlet-triplet dual emission, the properties of linearly conjugated donor-acceptor complexes [Pt(N,N-BNPA)Ph2] (3a) and [Pt(N,C-BNPA)Ph2] (3b) were also examined. Consistent with 2a and 2b, the N,C-chelate complex 3b has a much higher phosphorescent efficiency than the N,N-chelate 3a. Although 3a and 3b show bright and fluoride-switchable phosphorescence at ambient temperature, they are not dual emissive and show only metal-to-ligand chage-transfer-based phosphorescence. The non-conjugated donor-acceptor geometry and the overlap of the donor and acceptor singlet and triplet excitation bands in Si-BNPA and its Pt(II) complexes may thus be the key for achieving singlet-triplet dual emission on two separated chromophores in a single molecule.

The anionic coordination polymer {K2[Pt(II)2Ag(I)8(2,2'-bipyridine)2(O2CCF3)14]}n.

The trimetallic compound catena-poly[dipotassium(I) [bis(2,2'-bipyridine)di-mu3-trifluoroacetato-dodeca-mu2-trifluoroacetato-diplatinum(II)octasilver(I)]], K2[Pt2Ag8(C2F3O2)14(C10H8N2)2], forms an extended structure in the solid state. Electrostatic interactions involving the K+ ions play a key role in the formation of the extended structure in three dimensions. The Ag(I) ions form one-dimensional coordination polymers, with alternating Ag2 and Ag6 units linked by CF3CO2- ligands. Pt...Pt interactions perpendicular to the one-dimensional polymerization axis provide another element of long-range order, and electrostatic interactions with K+ ions provide connectivity between adjacent polymeric structures.

Reversible intramolecular C-C bond formation/breaking and color switching mediated by a N,C-chelate in (2-ph-py)BMes2 and (5-BMes2-2-ph-py)BMes2.

A diboron compound with both 3-coordinate boron and 4-coordinate boron centers, (5-BMes2-2-ph-py)BMes2 (1) and its monoboron analogue, (2-ph-py)BMes2 (2) have been synthesized. Both compounds are luminescent but have a high sensitivity toward light. UV and ambient light cause both compounds to isomerize to 1a and 2a, respectively, via the formation of a C-C bond between a mesityl and the phenyl group, accompanied by a drastic color change from yellow or colorless to dark olive green or dark blue. The structures of 1a and 2a were established by 2D NMR experiments and geometry optimization by DFT calculations. Both 1a and 2a can thermally reverse back to 1 and 2 via the breaking of a C-C bond, with the activation barrier being 107 and 110 kJ/mol, respectively. The N,C-chelate ligands in 1 and 2 were found to play a key role in promoting this unusual and reversible photo-thermal isomerization process on a tetrahedral boron center. Reactions with oxygen molecules convert 1a and 2a to 5-BMes2-2-[(2-Mes)-ph]-pyridine (1b) and 2-(2-Mes)-ph-pyridine (2b), respectively.

Electrophilic fluorination of cationic Pt-aryl complexes.

The electrophilic fluorination of several (triphos)Pt-aryl(+) establishes the first example of aryl-F coupling from a Pt center.

Dinuclear Cu(I) complexes of 1,2,4,5-tetra(7-azaindolyl)benzene: persistent 3-coordinate geometry, luminescence, and reactivity.

Five Cu(I) complexes [Cu2(ttab)(CH3CN)2][BF4]2 (1), [Cu(2)(ttab)(PPh3)2][BF4]2 (2), [Cu2(ttab)I2] (3), [Cu2(ttab)(I3)2] (4), and [Cu2(ttab)(I)BF4]n (5) with 1,2,4,5-tetra(7-azaindolyl)benzene (ttab) have been synthesized and characterized. The structures of compound 1, 2, 4, and 5 have been determined by single-crystal X-ray diffraction analyses, which established that 1, 2, and 4 are discrete dinuclear Cu2 compounds while compound 5 is a 1D coordination polymer with the I- ligand bridging two dinuclear Cu2 units. The ttab ligand in all four complexes adopts a 1,3-chelation mode. The Cu(I) center in all complexes is three-coordinate. Close contact between the Cu(I) center and the benzene ring in the ttab ligand was observed in all four structures, which is believed to play a role in stabilizing the three-coordinate geometry of the Cu(I) center. The crystals of 1, 2, and 5 contain channels in the lattice that host solvent molecules such as CH2Cl2 and toluene. Fluorescent measurements established that, in solution, compounds 1-3 display weak blue luminescence which originates from the ttab but is significantly red-shifted and has a much lower emission intensity, compared to the free ttab ligand. The application of compound 1 in C-N cross-coupling reactions was examined by using the reaction of phenyl halides with imidazole as a model system. For the reaction with phenyl iodide, 1 was found to be as effective a catalyst as the CuI/1,10-phenanthroline system. For the reaction with phenyl bromide, 1 is less effective than the CuI/1,10-phenanthroline system. Compound 1 reacts with O2 gas, as established by UV-vis spectra, but the oxidized products have not been characterized.

7-Azaindolyl- and 2,2'-dipyridylamino-functionalized molecular stars with sixfold symmetry: self-assembly, luminescence, and coordination compounds.

Two novel star molecules functionalized with 7-azaindolyl and 2,2'-dipyridylamino groups have been synthesized. Both molecules possess a sixfold rotation symmetry. Molecule L1 is based on the hexaphenylbenzene core with the formula of hexa[p-(7-azaindolyl)phenyl]benzene, while molecule L2 is based on the hexakis(biphenyl)benzene core with the formula of hexa[p-(2,2'-dipyridylamino)biphenyl]benzene. Both compounds have been characterized by single-crystal X-ray diffraction analyses. Molecule L1 forms extended two-dimensional layered structure, while L2 forms interpenetrating columnar stacks in the solid state, as revealed by X-ray diffraction analyses. Nanowire structures based on columnar stacks through self-assembly of L2 on a graphite surface were revealed by an STM study. Molecules L1 and L2 are capable of binding to metal ions, resulting in unusual structural motifs. Two Ag(I) complexes with the formulae of [(AgNO(3))(2)(L1)] (1) and [(AgNO(3))(3)(L1)] (2) were isolated from the reactions of AgNO(3) with L1. Compound 1 displays extended intermolecular pi-pi stacking interactions that are responsible for its extended two-dimensional structure in the crystal lattice. Complex 2 has a "bowl" shape and forms polar stacks in the crystal lattice. A Cu(II) complex with the formula of [{Cu(NO(3))(2)}(6)(L 2)] (3) was isolated from the reaction of Cu(NO(3))(2) with compound L2. The six Cu(II) ions in 3 are chelated by the 2,2'-dipyridylamino groups of the star ligand L2. Intermolecular Cu-O (nitrate) bonds lead to the formation of an extended two-dimensional coordination network of 3. Both L1 and L2 are blue luminescent. Their interactions with Ag(I) or Cu(II) cause drastic quenching of emission. In addition, the luminescence of L1 and L2 is sensitive to the presence of protons, which cause a reduction of emission intensity and a red shift of the emission energy.

Palladium(II) complexes of bowls, pinwheels, cages, and N,C,N-pincers of starburst ligands 1,3,5-Tris(di-2-pyridylamino)benzene and 2,4,6-Tris(di-2-pyridylamino)-1,3,5-triazene.

The reactions of Pd(II) ions with starburst ligands 1,3,5-tris(di-2-pyridylamino)benzene (tdab) and 2,4,6-tris(di-2-pyridylamino)-1,3,5-triazene (tdat) have been investigated. Complexes with the Pd:tdab (or tdat) ratio being 1:1 and 3:1 have been isolated and characterized. The structures of five new Pd(II) complexes containing the starburst ligands have been determined by X-ray diffraction analyses, which include chelate compounds [PdCl(2)(tdab)], 1, [(PdCl(2))(3)(tdab)], 2, [(Pd(OAc)(2))(3)(tdab)], 4, and [(Pd(OAc)(2))(3)(tdat)], 5, and a cyclometalated compound [Pd(OAc)(NCN-tdab)], 3. The Pd(II) ion in the 1:1 compound 1 is chelated by two pyridyl groups. Similarly, each Pd(II) center in the 3:1 compounds 2, 4, and 5 is chelated by two pyridyl groups. However, these three compounds display distinct structural features: 2 adopts a "bowl-shaped" structure, 4 has a "pinwheel"-like structure, and 5 has a "up-and-down" structure. Compounds 4 and 5 were examined in solution by variable-temperature (1)H NMR, which revealed that both compounds retain the "pinwheel" and the "up-and-down" structure, respectively. The observed structural preference by 4 and 5 is attributed to both electronic and steric factors.

Three-coordinate organoboron compounds BAr2R (Ar = mesityl, R = 7-azaindolyl- or 2,2'-dipyridylamino-functionalized aryl or thienyl) for electroluminescent devices and supramolecular assembly.

Eight novel three-coordinate boron compounds with the general formula BAr(2)L, in which Ar is mesityl and L is a 7-azaindolyl- or a 2,2'-dipyridylamino-functionalized aryl or thienyl ligand, have been synthesized by Suzuki coupling, Ullmann condensation methods, or simple substitution reactions (L = p-(2,2'-dipyridylamino)phenyl, 1; p-(2,2'-dipyridylamino)biphenyl, 2; p-(7-azaindolyl)phenyl, 3; p-(7-azaindolyl)biphenyl, 4; 3,5-bis(2,2'-dipyridylamino)phenyl, 5; 3,5-bis(7-azaindolyl)phenyl, 6; p-[3,5-bis(2,2'-dipyridylamino)phenyl]phenyl, 7; 5-[p-(2,2'-dipyridylamino)phenyl]-2-thienyl, 8). The structures of 1, 3, and 5-7 have been determined by X-ray diffraction analyses. These new boron compounds are bright blue emitters. Electroluminescent devices using compound 2 or 8 as the emitter and the electron-transport layer have been successfully fabricated. Molecular orbital calculations (Gaussian 98) have established that the blue emission of compounds 1-8 originates from charge transfer between the pi orbital of the ligand L and the p(pi) orbital of the boron center. The ability of these boron compounds to bind to metal centers to form supramolecular assemblies was demonstrated by treatment of compound 2 with Zn(O(2)CCF(3))(2), which generated a 1:1 chelate complex [2.Zn(O(2)CCF(3))(2)] (10), and also by treatment of compound 4 with AgNO(3), yielding a 2:1 coordination compound [(4)(2).Ag(NO(3))] (11). In the solid state, compounds 10 and 11 form interesting head-to-head and tail-to-tail extended structures that host solvent molecules such as benzene.