Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 10 de 10
Filtrar
Mais filtros








Base de dados
Intervalo de ano de publicação
1.
Int J Infect Dis ; 142: 106954, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38382822

RESUMO

OBJECTIVES: Streptococcal toxic shock syndrome (STSS) is caused by group A Streptococcus (GAS; Streptococcus pyogenes) strains. In Japan, the number of STSS cases has decreased; however, the underlying reason remains unclear. Moreover, information on distribution and prevalence of specific emm types in STSS cases is scarce. Hence, we investigated the reason for the decreased number of STSS cases in Japan. METHODS: We genotyped emm of 526 GAS isolates obtained from 526 patients with STSS between 2019 and 2022. The distributions of emm types in each year were compared. RESULTS: The emm1 type was predominant, with the highest proportion in 2019, which decreased after 2020 following the onset of the coronavirus disease 2019 (COVID-19) pandemic. Strains isolated during the pandemic correlated with strains associated with skin infection, whereas those isolated during the prepandemic period correlated with strains associated with both throat and skin infections. The decrease in the annual number of STSS cases during the COVID-19 pandemic could be due to a decreased proportion of strains associated with pharyngeal infections. CONCLUSIONS: Potential associations between pandemic and STSS numbers with respect to public health measures, such as wearing masks and changes in healthcare-seeking behavior, may have affected the number of GAS-induced infections.


Assuntos
COVID-19 , Choque Séptico , Infecções Estreptocócicas , Humanos , Streptococcus pyogenes/genética , Choque Séptico/epidemiologia , Japão/epidemiologia , Pandemias , COVID-19/epidemiologia , Infecções Estreptocócicas/epidemiologia
2.
Respirol Case Rep ; 11(6): e01163, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37206158

RESUMO

Alveolar-pleural fistulas that do not improve with thoracic drainage can be conservatively treated via endobronchial occlusion and pleurodesis, among other options. However, for inoperable cases, the treatment strategy to be followed, in the event that conventional conservative management fails, is unclear. Herein, we report a case of alveolar-pleural fistula managed by bronchial occlusion using a combination of Endobronchial Watanabe Spigot (EWS) and N-butyl-2-cyanoacrylate (NBCA). A 79-year-old man on prednisolone for interstitial pneumonia with autoimmune features was diagnosed with invasive pulmonary aspergillosis and Aspergillus pyothorax infection. He was administered voriconazole; however, a pneumothorax developed and did not improve with thoracic drainage. Bronchial occlusion with EWS failed due to spigot migration. However, a combination of EWS with NBCA could control the alveolar-pleural fistula. Thus, an EWS and NBCA combination may help prevent EWS migration, providing another option for patients who are unfit for surgery.

3.
Respirol Case Rep ; 11(1): e01078, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36569636

RESUMO

The diagnosis of pulmonary leiomyosarcoma using bronchoscopy is difficult, and surgical resection is often performed for definitive diagnosis and curative therapy. We report a case of pulmonary leiomyosarcoma, successfully diagnosed using repeated transbronchial cryobiopsy (TBCB). A 69-year-old-woman was found to have an oval mass in the left hilar region extending into the left main bronchus on computed tomography (CT). All transbronchial biopsy specimens were necrotic, but repeated TBCB removed the necrotic tissue from the tumour and finally led to the diagnosis of pulmonary leiomyosarcoma. Proton therapy was administered, which caused shrinkage of the tumour. Thus, TBCB is useful for definitive diagnosis of leiomyosarcoma without surgical biopsy. Repeated TBCB can reduce tumour volume, eliminate atelectasis, and reduce the extent of radiotherapy exposure.

4.
J Antibiot (Tokyo) ; 66(3): 155-9, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23385133

RESUMO

An alternative and improved total synthesis of incednam, the aglycon of the 24-membered macrolactam glycoside antibiotic incednine, was accomplished. The synthesis was realized via construction of the 24-membered macrocycle using intramolecular ring-closing olefin metathesis reaction as a key step.


Assuntos
Antibacterianos/síntese química , Compostos Macrocíclicos/síntese química , Alcenos/química , Antibacterianos/química , Dissacarídeos/química , Lactamas/química , Compostos Macrocíclicos/química
5.
Dalton Trans ; 42(14): 4809-21, 2013 Apr 14.
Artigo em Inglês | MEDLINE | ID: mdl-23360893

RESUMO

Vapochromic complexes [Au(im(CH(2)py)(2))(2)(Cu(MeCN)(2))(2)](3+) 1, [Au(im(CH(2)py)(2))(2)(Cu(MeOH))(2)](3+) 2 and [Au(im(CH(2)py)(2))(2)(Cu(H(2)O))(2)](3+) 3 were theoretically investigated. The Au­Cu distances of 1 and 2 (4.631 Å and 2.767 Å, respectively) optimized by the SCS-MP2 method in this work agree with the literature experimental values (4.591 Å and 2.792 Å). Their structural features are explained by computational results: (i) in 1, two MeCN molecules coordinate with the Cu center, because of the strong coordination ability of MeCN, to afford a four-coordinate tetrahedral-like Cu center. This geometry needs a long Au­Cu distance. (ii) In 2 and 3, only one MeOH or H(2)O molecule coordinates with the Cu center because of their weak coordination abilities, to afford a three-coordinate planar Cu center. Because the three-coordinate Cu center is flexible, the Au­Cu distance becomes short due to the Au­Cu metallophilic interaction, the strength of which is 5.3 kcal mol(−1) at the SCS-MP2 level. The emission energies of 1, 2 and 3 (2.62, 2.40 and 2.38 eV, respectively) calculated here by the B3PW91 agree with their literature experimental values (2.68, 2.47, and 2.39 eV). The lowest energy triplet excited state (T(1)) is assigned as the excitation from the Cu d to the pyridine π* orbital in 1 and that from the Au­Cu 5d­3d anti-bonding MO to the Au­Cu 6p­4sp bonding MO in 2 and 3. As a result, the emission energy from the T(1) to the ground state is different between these compounds. The difference in Au­Cu distance is one of the important factors for the differences in emission energy and assignment between 1 and others (2 and 3). The vapochromism of these compounds arises from the difference in Au­Cu distance which is determined by the balance between the strengths of the coordination of a gas molecule and the Au­Cu metallophilic interaction; in other words, the Au­Cu heterometallophilic interaction is important for the vapochromic activity of the complex.

6.
J Phys Chem A ; 115(30): 8520-7, 2011 Aug 04.
Artigo em Inglês | MEDLINE | ID: mdl-21710982

RESUMO

The molecular structure and the binding energy of Pt(PR(3))(2)(AlCl(3)) (R = H, Me, Ph, or Cy) were investigated by DFT, MP2 to MP4(SDTQ), and CCSD(T) methods. The optimized structure of Pt(PCy(3))(2)(AlCl(3)) (Cy = cyclohexyl) by the DFT method with M06-2X and LC-BLYP functionals agrees well with the experimental one. The MP4(SDTQ) and CCSD(T) methods present similar binding energies (BE) of Pt(PH(3))(2)(AlCl(3)), indicating that these methods provide reliable BE value. The DFT(M06-2X)-calculated BE value is close to the MP4(SDTQ) and CCSD(T)-calculated values, while the other functionals present BE values considerably different from the MP4(SDTQ) and CCSD(T)-calculated values. All computational methods employed here indicate that the BE values of Pt(PMe(3))(2)(AlCl(3)) and Pt(PPh(3))(2)(AlCl(3)) are considerably larger than those of the ethylene analogues. The coordinate bond of AlCl(3) with Pt(PR(3))(2) is characterized to be the σ charge transfer (CT) from Pt to AlCl(3). This complex has a T-shaped structure unlike the well-known Y-shaped structure of Pt(PMe(3))(2)(C(2)H(4)), although both are three-coordinate Pt(0) complex. This T-shaped structure results from important participation of the Pt d(σ) orbital in the σ-CT; because the Pt d(σ) orbital energy becomes lower as the P-Pt-P angle decreases, the T-shaped structure is more favorable for the σ-CT than is the Y-shaped structure. [Co(alcn)(2)(AlCl(3))](-) (alcn = acetylacetoneiminate) is theoretically predicted here as a good candidate for the metal complex, which has an unsupported M-Al bond because its binding energy is calculated to be much larger than that of Pt(PCy(3))(2)(AlCl(3)).

7.
Org Lett ; 12(21): 5068-71, 2010 Nov 05.
Artigo em Inglês | MEDLINE | ID: mdl-20939604

RESUMO

The first total synthesis of incednam (1), the aglycon of antibiotic incednine (2), is described. Incednine has been reported to exhibit significant inhibitory activity against the antiapoptotic oncoproteins Bcl-2 and Bcl-xL. The synthesis of 1 commenced with the preparation of the C1-C13 subunit 3 and the C14-C23 subunit 4. The construction of the novel 24-membered macrocycle was achieved by the application of a Stille coupling between 3 and 4, followed by macrolactamization.


Assuntos
Dissacarídeos/síntese química , Lactamas/síntese química , Compostos Macrocíclicos/síntese química , Estrutura Molecular
8.
Chemistry ; 14(17): 5258-66, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18446910

RESUMO

A new series of tripods were designed to form anion-responsive, luminescent lanthanide complexes. These tripods contain pyridine, thiazole, pyrazine, or quinoline chromophores combined with amide carbonyl oxygen and tertiary nitrogen atoms. Crystallographic and EXAFS studies of the 10-coordinated tripod-La(NO(3))(3) complexes revealed that each La(3+) cation was cooperatively coordinated by one tetradentate tripod and three bidentate NO(3)(-) anions in the crystal and in CH(3)CN. Quantum chemical calculations indicated that the aromatic nitrogen plays a significant role in lanthanide complexation. The experimentally determined stability constants of complexes of the tripod with La(NO(3))(3), Eu(NO(3))(3), and Tb(NO(3))(3) were in good agreement with the theoretically calculated interaction energies. Complexation of each tripod with lanthanide triflate gave a mixture of several lanthanide complex species. Interestingly, the addition of a coordinative NO(3)(-) or Cl(-) anion to the mixture significantly influenced the lanthanide complexation profiles. The particular combination of tripod and a luminescent Eu(3+) center gave anion-selective luminescence enhancements. Pyridine-containing tripods exhibited the highest NO(3)(-) anion-selective luminescence and thus permit naked-eye detection of the NO(3)(-) anion.


Assuntos
Compostos Heterocíclicos/química , Elementos da Série dos Lantanídeos/química , Luminescência , Acetonitrilas/química , Ânions/química , Cristalografia por Raios X , Ligantes , Espectroscopia de Ressonância Magnética , Espectrofotometria Ultravioleta
9.
J Comput Chem ; 28(15): 2424-30, 2007 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-17708534

RESUMO

We developed new model core potentials (MCPs) for s-block elements from Na to Ra, in which the outer core (n-1)s and (n-1)p electrons are treated explicitly together with the ns electrons. By adding suitable correlating functions, we demonstrated that the present MCP basis sets show excellent performance in describing the electronic structures of atoms and molecules, bringing about accurate ionization potentials of atoms and very good spectroscopic constants of ionic and covalent molecules. The results obtained with the new MCPs are very close to the ones obtained using the all-electron correlation consistent basis sets of Dunning.

10.
Langmuir ; 20(12): 5046-51, 2004 Jun 08.
Artigo em Inglês | MEDLINE | ID: mdl-15984267

RESUMO

An attempt was made to arrange polystyrene latex particles (2, 5, and 10 microm in diameter) dispersed in aqueous media making use of their dielectrophoresis and electrophoresis with a hyperbolic quadruple electrode system. Application of a high-frequency ac field enabled the particles to arrange themselves between the electrodes forming a particle monolayer due to the negative dielectrophoretic force. Simultaneous application of high-frequency ac and dc fields caused the particles to gather in the region surrounded by the electrodes to form particle multilayers. Appropriate choice of the way of applying an electric field thus allowed the reversible control of particle arrangements (monolayer, multilayer, dispersion). Reapplication of an ac field to the particle layers produced highly dense particle multilayers.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA