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2.
J Org Chem ; 88(21): 15444-15451, 2023 Nov 03.
Artigo em Inglês | MEDLINE | ID: mdl-36099541

RESUMO

Tetrabutylammonium acetate (TBAA) and Cu(OAc)2 worked as a binary catalytic system for the solvent-free N-formylation of amines with CO2 and PhSiH3. This catalysis making C-H and C-N bonds with CO2 was coupled with the C-C bond-forming reactions to achieve the one-pot synthesis of enamines, aldehydes, and nitriles. The X-ray crystal structure of a Cu(OAc)2-TBAA complex was also revealed.

3.
BMC Nephrol ; 22(1): 122, 2021 04 07.
Artigo em Inglês | MEDLINE | ID: mdl-33827474

RESUMO

BACKGROUND: Behçet's disease (BD) is a systemic inflammatory vasculitis with both autoimmune and autoinflammatory properties. Renal involvement in BD and its spontaneous remission have been rare. We herein describe a case of parallel disease activity of BD with entero and renal involvements, followed by a spontaneous remission without corticosteroid treatment. CASE PRESENTATION: A 54-year-old woman who had a 4-year history of BD, maintained with colchicine treatment, suffered abdominal pain, hemorrhagic stool and diarrhea. Physical examination revealed strong tenderness in the entire abdomen. Laboratory test results showed increased levels of inflammation, and a computed tomography scan revealed edematous intestinal wall thickening with ascites. Blood and stool cultures showed no specific findings. Since she was suspected to have developed panperitonitis with acute enterocolitis, she started treatment with an antibacterial agent under bowel rest. Her abdominal symptoms gradually improved, while diarrhea and high levels of inflammatory reaction persisted. Colonoscopy revealed discontinuous abnormal mucosal vascular patterns and ulcerations in the whole colon except for the rectum, and histological analyses of the intestine demonstrated transmural mucosal infiltration of inflammatory cells without epithelioid granuloma or amyloid deposition. Based on these findings, she was diagnosed with entero BD. Meanwhile, pedal edema appeared during her hospitalization. Urinalysis results were consistent with nephrotic syndrome, thus a renal biopsy was performed. Light microscopy showed no obvious glomerular and interstitial abnormalities, whereas electron microscopy revealed foot process effacement without immune complex deposition or fibrillary structure, compatible with minimal change disease (MCD). Only with conservative therapy, her proteinuria decreased, followed by a complete remission in 3 weeks from the onset of edema. The coincident episode of MCD was finally diagnosed as renal BD that paralleled disease activity to entero BD. She started adalimumab administration, resulting in the further improvement of diarrhea and inflammatory levels. CONCLUSIONS: This is the first report to demonstrate MCD as renal involvement of BD along with the disease activity of entero BD.


Assuntos
Síndrome de Behçet/complicações , Rim/patologia , Nefrose Lipoide/etiologia , Colo/patologia , Feminino , Humanos , Melena/etiologia , Pessoa de Meia-Idade , Nefrose Lipoide/diagnóstico , Proteinúria/etiologia , Remissão Espontânea
4.
Mod Rheumatol ; 31(3): 593-599, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-32820698

RESUMO

OBJECTIVE: No evidence has shown the efficacy of Sodium Risedronate (Risedronate) for glucocorticoid-induced osteoporosis (GIO) in patients with Rheumatoid arthritis (RA). The aim of this study was to explore the effectiveness and safety of Risedronate for GIO complicated with RA. METHODS: This was a six-month randomized, double-blind, placebo-controlled trial of 95 patients with GIO complicated with RA from 19 centers. The primary endpoint was the change from baseline in lumbar spine bone mineral density (L-BMD). Secondary endpoints included changes in femoral neck and total hip BMD and bone turnover markers, as well as rheumatoid arthritis Disease Activity Score with 28-joint counts. Incident of non-traumatic spine fractures and adverse events were tracked as safety endpoints. RESULTS: Increase in L-BMD was significantly greater in the Risedronate group compared to the Placebo group (Risedronate: 3.49% [95% CI: 1.92-5.05] vs Placebo: 0.12% [95% CI: -2.07 to 2.30], p < .0001). No significant difference was found in the femoral neck and total hip BMD. Although adverse events were observed in 28 patients, none were considered serious. Non-traumatic vertebral fractures were identified in 10 patients. CONCLUSION: Risedronate was effective in increasing L-BMD and was well tolerated in patients with GIO complicated with RA.


Assuntos
Conservadores da Densidade Óssea/uso terapêutico , Osteoporose/tratamento farmacológico , Ácido Risedrônico/uso terapêutico , Idoso , Artrite Reumatoide/tratamento farmacológico , Densidade Óssea , Conservadores da Densidade Óssea/administração & dosagem , Conservadores da Densidade Óssea/efeitos adversos , Método Duplo-Cego , Feminino , Glucocorticoides/efeitos adversos , Glucocorticoides/uso terapêutico , Humanos , Vértebras Lombares/patologia , Masculino , Pessoa de Meia-Idade , Osteoporose/etiologia , Ácido Risedrônico/administração & dosagem , Ácido Risedrônico/efeitos adversos
5.
Arthritis Rheum ; 60(8): 2457-67, 2009 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-19644870

RESUMO

OBJECTIVE: Antibodies to prothrombin (APTs) and to beta2-glycoprotein I are the major autoantibodies responsible for lupus anticoagulant (LAC) activity. APTs comprise antibodies against prothrombin alone as well as antibodies against phosphatidylserine/prothrombin complex (anti-PS/PT), the latter being highly associated with the antiphospholipid syndrome (APS). The effect of anti-PS/PT on thrombin generation has not been elucidated, and the paradoxical effect of LAC (an anticoagulant in vitro, but a procoagulant in vivo) remains an enigma. The purpose of this study was to investigate the effects of anti-PS/PT on thrombin generation and to examine the LAC paradox. METHODS: We evaluated 36 anti-PS/PT-positive APS patients and 127 healthy subjects. Markers of in vivo thrombin/fibrin generation, including prothrombin fragment F1+2, thrombin-antithrombin III complex, soluble fibrin monomer, D-dimer, and fibrin degradation products, were measured. Mouse monoclonal anti-PS/PT antibody 231D was established, and its effects on in vitro thrombin generation were investigated by chromogenic assay. RESULTS: Significantly elevated levels of markers of thrombin/fibrin generation were observed in anti-PS/PT-positive patients, regardless of the presence or absence of anticardiolipin antibodies, as compared with healthy subjects. In the presence of low concentrations of human activated factor V (FVa), monoclonal antibody 231D increased thrombin generation in a dose-dependent manner. In contrast, when high concentrations of FVa were added, monoclonal antibody 231D decreased thrombin generation. Under a constant concentration of FVa, a high concentration of human FXa enhanced the effect of 231D. CONCLUSION: The presence of anti-PS/PT greatly correlated with increased thrombin generation in APS patients. The in vitro effects of monoclonal antibody 231D on thrombin generation are "biaxial" according to the FVa/FXa balance. These data may serve as a clue to understanding the LAC paradox and the thrombogenic properties of anti-PS/PT.


Assuntos
Síndrome Antifosfolipídica/sangue , Autoanticorpos/sangue , Fibrina/metabolismo , Fosfatidilserinas/imunologia , Protrombina/imunologia , Trombina/metabolismo , Adolescente , Adulto , Idoso , Animais , Anticorpos Monoclonais/biossíntese , Anticorpos Monoclonais/farmacologia , Síndrome Antifosfolipídica/imunologia , Biomarcadores/metabolismo , Células Cultivadas , Feminino , Humanos , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Pessoa de Meia-Idade , Adulto Jovem
6.
J Chem Phys ; 128(6): 064507, 2008 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-18282056

RESUMO

In the present work, we have performed quantum chemical calculations to determine preferable species among the ionic complexes that are present in ambient water due to the autodissociation of water molecule. First, we have formulated the relative population of the hydrated complexes with respect to the bare ion (H(3)O(+) or OH(-)) in terms of the solvation free energies of the relevant molecules. The solvation free energies for various ionic species (H(3)O(+), H(5)O(2) (+), H(7)O(3) (+), H(9)O(4) (+) or OH(-), H(3)O(2) (-), H(5)O(3) (-), H(7)O(4) (-), H(9)O(5) (-)), categorized as proton or hydroxide ion in solution, have been computed by employing the QM/MM-ER method recently developed by combining the quantum mechanical/molecular mechanical (QM/MM) approach with the theory of energy representation (ER). Then, the computed solvation free energies have been used to evaluate the ratio of the populations of the ionic complexes to that of the bare ion (H(3)O(+) or OH(-)). Our results suggest that the Zundel form, i.e., H(5)O(2) (+), is the most preferable in the solution among the cationic species listed above though the Eigen form (H(9)O(4) (+)) is very close to the Zundel complex in the free energy, while the anionic fragment from water molecules mostly takes the form of OH(-). It has also been found that the loss of the translational entropy of water molecules associated with the formation of the complex plays a role in determining the preferable size of the cluster.


Assuntos
Simulação por Computador , Hidróxidos/química , Modelos Químicos , Teoria Quântica , Termodinâmica , Água/química , Prótons , Soluções/química
7.
J Phys Chem A ; 111(18): 3633-41, 2007 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-17439110

RESUMO

We have investigated the static second hyperpolarizabilities (gamma) of the singlet diradical systems with intermediate diradical character involving phenalenyl radicals connected by acetylene and vinylene pi-conjugated linkers, 1 and 2, using the hybrid density functional theory. For comparison, we have also examined the gamma values of the closed-shell and pure diradical systems with almost the same molecular size as 1 and 2. In agreement with our previous prediction of the diradical character dependence of gamma, it turns out that the gamma values of 1 and 2 are significantly enhanced compared to those of the closed-shell and pure diradical systems. In the present case, distinct differences in gamma values are not observed between the two pi-conjugated linkers, though the diradical character is found to depend on the kind of linker. Furthermore, we have investigated the spin multiplicity effect on gamma. Changing from the singlet to the triplet state, the gamma values of the systems with intermediate diradical character in the singlet state are quite reduced, though those of the pure diradical systems are hardly changed. Such spin multiplicity dependence of gamma is understood by considering the difference of diradical character between their singlet states together with the Pauli principle. The present results provide a possibility of a novel control scheme of gamma for phenalenyl radical systems involving pi-conjugated linkers by adjusting the diradical character through the change of the linked position of pi-conjugated linkers and the spin multiplicity.

8.
J Chem Phys ; 126(8): 084508, 2007 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-17343459

RESUMO

The Beckmann rearrangement of acetone oxime promoted by proton transfers in the supercritical water has been investigated by means of the hybrid quantum mechanical/molecular mechanical approach combined with the theory of energy representation (QM/MM-ER) recently developed. The transition state (TS) structures have been explored by ab initio calculations for the reaction of hydrated acetone oxime on the assumption that the reaction is catalyzed by proton transfers along the hydrogen bonds connecting the solute and the solvent water molecules. Up to two water molecules have been considered as reactants that take part in the proton transfers. As a result of the density functional theory calculations with B3LYP functional and aug-cc-pVDZ basis set, it has been found that participation of two water molecules in the reaction reduces the activation free energy by -12.3 kcal/mol. Furthermore, the QM/MM-ER simulations have revealed that the TS is more stabilized than the reactant state in the supercritical water by 2.7 kcal/mol when two water molecules are involved in the reaction. Solvation free energies of the reactant and the TS have been decomposed into terms due to the electronic polarization of the solute, electron density fluctuation, and others to elucidate the origin of the stabilization of the TS as compared with the reactant. It has been revealed that the promotion of the chemical reaction due to the hydration mainly originates from the interaction between the nonpolarized solute and the solvent water molecules at the supercritical state.

10.
J Phys Chem B ; 111(3): 581-8, 2007 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-17228916

RESUMO

We have applied the quantum mechanical/molecular mechanical (QM/MM) method combined with the theory of energy representation (ER) to study the acidity of acetic acid in aqueous solution. We have focused our attention on the relative acidity DeltapK(a) of the molecule with respect to water solvent to circumvent the ambiguity of the solvation free energies of the molecular species referred to as proton. The value of DeltapK(a) for the acetic acid has been computed as -11.5 when we adopt the free energy change in the gas phase obtained by the B3LYP functional, which is in excellent agreement with the experimental value of -11.0. It has been demonstrated that the QM/MM-ER approach recently developed gives an adequate description for the solvation free energies related to the acidity/basicity calculations of organic molecules.


Assuntos
Ácido Acético/química , Algoritmos , Simulação por Computador , Transferência de Energia , Concentração de Íons de Hidrogênio , Cinética , Modelos Moleculares , Prótons , Soluções , Termodinâmica , Água/química
11.
J Chem Phys ; 125(23): 234707, 2006 Dec 21.
Artigo em Inglês | MEDLINE | ID: mdl-17190570

RESUMO

The exciton dynamics of model aggregate systems, dimer, trimer, and pentamer, composed of two-state monomers is computationally investigated in the presence of three types of quantized optical fields, i.e., coherent, amplitude-squeezed, and phase-squeezed fields, in comparison with the case of classical laser fields. The constituent monomers are assumed to interact with each other by the dipole-dipole interaction, and the two-exciton model, which takes into account both the one- and two-exciton generations, is employed. As shown in previous studies, near-degenerate exciton states in the presence of a (near) resonant classical laser field create quantum superposition states and thus cause the spatial exciton recurrence motion after cutting the applied field. In contrast, continuously applied quantized optical fields turn out to induce similar exciton recurrence motions in the quiescent region between the collapse and revival behaviors of Rabi oscillation. The spatial features of exciton recurrence motions are shown to depend on the architecture of aggregates. It is also found that the coherent and amplitude-squeezed fields tend to induce longer-term exciton recurrence behavior than the phase-squeezed field. These features have a possibility for opening up a novel creation and control scheme of exciton recurrence motions in aggregate systems under the quantized optical fields.

12.
J Chem Phys ; 125(7): 074113, 2006 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-16942328

RESUMO

The origin of the diradical character dependence of the second hyperpolarizability (gamma) of neutral singlet diradical systems is clarified based on the perturbation formula of gamma using the simplest diradical molecular model with different diradical characters, i.e., H2 under bond dissociation. The enhancement of gamma in the intermediate diradical character region turns out to originate from the increasing magnitude of the transition moment between the first and second excited states and the decrease of that between the ground and first excited states, respectively, with the increase in diradical character. This feature confirms that open-shell singlet conjugated molecules with intermediate diradical characters constitute a new class of third-order nonlinear optical systems, whose gamma values can be controlled by the diradical character in addition to the conjugation length.

13.
J Phys Chem A ; 110(12): 4238-43, 2006 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-16553375

RESUMO

The second hyperpolarizabilities of bisimidazole- and bistriazole-benzene compounds have been calculated at different levels of approximation to unravel the effects of diradical character as well as of charge and spin multiplicity. The largest second hyperpolarizabilities are associated with intermediate diradical character, provided positive charging does not compensate for this effect. For the neutral diradical bisimidazole compound, the singlet diradical species possesses a second hyperpolarizability two to three times larger than the corresponding triplet, demonstrating the possibility of spin state control of the third-order NLO responses for diradical species.


Assuntos
Derivados de Benzeno/química , Imidazóis/química , Teoria Quântica , Triazóis/química , Simulação por Computador , Radicais Livres/química , Modelos Químicos , Estrutura Molecular
16.
Biomaterials ; 24(23): 4253-64, 2003 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-12853257

RESUMO

A variety of neutral and cationic polymers based on polyamino acids were prepared and investigated as microcarriers for cell attachment and growth. Among neutral polymer particles including the alkylated poly(gamma-methyl L-glutamate) (PG) particles, in which the hydrophobicity changes as a function of the length of the alkyl groups, and hydroxy terminal PG particles, the PG particle with the longest alkyl chain (PG-C12) demonstrated the highest cell attachment rate and highest rate of cell growth. Moreover, the introduction of hydroxyl groups (PG-OH) led to a deterioration of cell growth. Cell growth on cationic particles having primary amino groups was drastically dependent upon the anion exchange capacity (AEC). A higher AEC for aminated PG microcarriers inhibited cell growth. In contrast, a higher AEC for cross-linked poly( epsilon -lysine) (PL) microcarriers facilitated cell growth. Cell growth on cationic particles clearly showed a good correlation with the pK(a,app) of the microcarriers, but not with their AEC. The particles with low and high pK(a) values possessed toxically acidic and basic pH microenvironments near the surface, respectively. These microenvironments had cytotoxic effects. On the other hand, no correlation between attachment rate constants and high cell growth was observed. The aminated particles, in which pK(a) were controlled at neutral pH, and PG-C12 produced obviously higher cell growth than did a commercially available microcarrier.


Assuntos
Técnicas de Cultura de Células/instrumentação , Técnicas de Cultura de Células/métodos , Ácido Poliglutâmico/análogos & derivados , Ácido Poliglutâmico/química , Polímeros/química , Aminoácidos/química , Animais , Ânions , Cátions , Divisão Celular , Linhagem Celular , Fibroblastos/metabolismo , Concentração de Íons de Hidrogênio , Cinética , Camundongos , Microscopia de Contraste de Fase , Modelos Químicos , Temperatura , Fatores de Tempo
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