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1.
J Neuroendovasc Ther ; 18(5): 131-136, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38808014

RESUMO

Objectives: We have been performing preoperative coronary artery assessments and implementing coronary revascularization or intraoperative adjunctive therapies as needed in patients scheduled for carotid artery stenting (CAS) to prevent ischemic heart disease. In this study, we report the results of a retrospective observation of patients who underwent CAS under our treatment strategy to prevent perioperative coronary ischemic complications. Methods: A total of 224 cases from January 2014 to December 2021 were included. Following preoperative coronary artery CTA, preoperative coronary artery treatment or intraoperative adjunctive therapy (temporary transcutaneous cardiac pacemaker [TTCP] or intra-aortic balloon pumping [IABP]) was performed based on the degree of stenosis. We analyzed the outcomes of patients treated with CAS under this strategy at our institution. Results: Coronary artery disease was detected preoperatively in 143 cases (64%), with 91 cases (41%) indicated for coronary revascularization. Preoperative coronary artery treatment was performed in 76 cases (34%) prior to CAS, and adjunctive therapy with TTCP or IABP was provided in 28 cases (13%) during the procedure. No case developed perioperative coronary ischemic complication. Conclusion: In patients who have undergone CAS, perioperative coronary ischemic complications might be reduced by evaluating the risk of ischemic heart disease preoperatively, performing pre-CAS coronary artery intervention based on the severity of the lesions, and administering intraoperative adjunctive therapy.

2.
J Neurol Sci ; 453: 120797, 2023 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-37703704

RESUMO

BACKGROUND AND PURPOSE: Whether subarachnoid haemorrhage (SAH) after mechanical thrombectomy affects the clinical outcomes of patients with acute large-vessel occlusion remains unclear. This study aimed to investigate the clinical impact of SAH on computed tomography (CT) after mechanical thrombectomy. METHODS: The SKIP study was an investigator-initiated, multicentre, randomised, open-label clinical trial. This study was performed in 23 hospital networks in Japan from January 1, 2017, to July 31, 2019. Among the 204 patients, seven were excluded because they did not undergo mechanical thrombectomy (MT) and had a modified Rankin scale (mRS) score > 2. The main outcome was the association between SAH within 36 h after mechanical thrombectomy and the clinical outcome at 90 days. RESULTS: Among 197 patients, the median age was 74 (67-79) years, 62.9% were male. Moreover, 26 (13.2%) patients had SAH (seven isolated SAH) on CT within 36 h. The SAH rate did not differ according to IV rt-PA administration (p = 0.4). The rate of favourable clinical outcomes tended to be lower in patients with SAH rather than patients without SAH (11 [42%] vs. 106 [62%], p = 0.08). Among the seven patients with isolated SAH, 6 showed favourable outcomes at 90 days. In the multivariate regression analysis, the presence of SAH within 36 h from onset was not associated with clinical outcome (Odd ratio, 0.59; 95% confidence interval, 0.18-1.95; p = 0.38). CONCLUSIONS: Among patients with acute stroke treated with MT, SAH, especially isolated SAH findings on CT, were not associated with poor clinical outcomes after 90 days. TRIAL REGISTRATION NUMBER: UMIN000021488.

3.
J Neurol Sci ; 453: 120772, 2023 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-37651883

RESUMO

BACKGROUND: To investigate whether ultra-early recombinant tissue-plasminogen activator (rt-PA) administration can improve patient outcomes on mechanical thrombectomy (MT) in patients with large vessel occlusion (LVO). METHODS: Participants comprised rt-PA-eligible 204 patients with internal carotid artery or middle cerebral artery occlusion in the SKIP trial, who were randomly assigned to receive mechanical thrombectomy alone or combined intravenous thrombolysis (rt-PA: alteplase at 0.6 mg/kg) plus mechanical thrombectomy. We assessed associations between onset-to-puncture time and onset-to-rt-PA administration time and frequency of favorable outcome at 90 days and any intracerebral hemorrhage (ICH) at 36 h after onset. RESULTS: As a cut-off onset-to-puncture time for favorable outcome, receiver operating characteristic curves defined 2.5 h (57% sensitivity, 62% specificity). For onset-to-puncture times ≤2.5 h and > 2.5 h, frequencies of favorable outcomes were 72% and 63% (p = 0.402) in patients with rt-PA therapy and 44% and 58% (p = 0.212) in patients without rt-PA therapy, respectively. In terms of onset-to-rt-PA administration time, frequencies of favorable outcomes among patients with ultra-early rt-PA administration at ≤100, >100 min after onset, and without rt-PA therapy with onset-to-puncture time ≤ 2.5 h, and with and without rt-PA therapy with onset-to-puncture time > 2.5 h were 84% and 64%, 63%, and 44% and 58%, respectively (p = 0.025). Frequencies of any ICH among those patients were 37% and 32%, 32%, and 63% and 40%, respectively (p = 0.006). CONCLUSION: Ultra-early rt-PA administration should improve patient outcomes on mechanical thrombectomy among patients with LVO. Relatively late rt-PA administration might increase the frequency of any ICH.

4.
Cell Mol Gastroenterol Hepatol ; 15(6): 1505-1524, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36521661

RESUMO

BACKGROUND & AIMS: Hirschsprung disease (HSCR) is a congenital disorder characterized by the absence of the enteric nervous system (ENS). HSCR potentially involves multiple gene aberrations and displays complex patterns of inheritance. Mutations of the RET gene, encoding the RET receptor tyrosine kinase, play a central role in the pathogenesis of HSCR. Although a wide variety of coding RET mutations have been identified, their pathogenetic significance in vivo has remained largely unclear. METHODS: We introduced a HSCR-associated RET missense mutation, RET(S811F), into the corresponding region (S812) of the mouse Ret gene. Pathogenetic impact of Ret(S812F) was assessed by histologic and functional analyses of the ENS and by biochemical analyses. Interactions of the Ret(S812F) allele with HSCR susceptibility genes, the RET9 allele and the Ednrb gene, were examined by genetic crossing in mice. RESULTS: RetS812F/+ mice displayed intestinal aganglionosis (incidence, 50%) or hypoganglionosis (50%), impaired differentiation of enteric neurons, defecation deficits, and increased lethality. Biochemical analyses revealed that Ret(S811F) protein was not only kinase-deficient but also abrogated function of wild-type RET in trans. Moreover, the Ret(S812F) allele interacted with other HSCR susceptibility genes and caused intestinal aganglionosis with full penetrance. CONCLUSIONS: This study demonstrates that a single RET missense mutation alone induces intestinal aganglionosis via a dominant-negative mechanism. The RetS812F/+ mice model HSCR displays dominant inheritance with incomplete penetrance and serves as a valuable platform for better understanding of the pathogenetic mechanism of HSCR caused by coding RET mutations.


Assuntos
Sistema Nervoso Entérico , Doença de Hirschsprung , Animais , Camundongos , Doença de Hirschsprung/genética , Proteínas Proto-Oncogênicas c-ret/genética , Proteínas Proto-Oncogênicas c-ret/metabolismo , Mutação/genética , Neurônios/metabolismo , Sistema Nervoso Entérico/metabolismo
5.
J Neuroendovasc Ther ; 16(12): 593-599, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-37502667

RESUMO

Objective: Mechanical thrombectomy (MT) for middle cerebral artery M2 occlusion (M2O) is challenging because the procedure is performed in a narrow and tortuous artery. In this study, we compared MT using an aspiration catheter (AC) versus a stent retriever (SR) used alone, and retrospectively evaluated the efficacy and safety of MT using an AC for M2O. Methods: Seventy-four consecutive patients who underwent MT for M2O at our institution between April 2016 and April 2020 were evaluated. The subjects were classified into those treated by AC (AC group) or SR alone (SR group). The AC group included patients treated by both contact aspiration and a combination technique of AC and SR. Background factors and outcomes, including modified treatment in cerebral infarction (mTICI) 2c-3 recanalization, were compared between the groups. Results: AC and SR groups consisted of 47 and 27 patients respectively. Among them, the rate of mTICI 2b-3 was 93.6% vs 92.6%, and that of mTICI 2c-3 was 72.3% vs 48.2% (P = 0.004). The perioperative symptomatic subarachnoid hemorrhage (SAH) rate was 0% vs 7.4%, and modified Rankin scale scores of 0-2 were 78.6% vs 50% (P = 0.03). In the AC group, the mTICI 2c-3 rate was higher in patients in whom the AC was adequately advanced to the thrombus compared to those with inadequate AC advancement (83.3% vs 36.3%, P = 0.002). Conclusion: The rate of mTICI 2c-3 was higher in the AC than SR group, with no cases of symptomatic SAH. MT using AC for M2O might achieve safe and effective thrombectomy.

6.
JAMA ; 325(3): 244-253, 2021 Jan 19.
Artigo em Inglês | MEDLINE | ID: mdl-33464334

RESUMO

IMPORTANCE: Whether intravenous thrombolysis is needed in combination with mechanical thrombectomy in patients with acute large vessel occlusion stroke is unclear. OBJECTIVE: To examine whether mechanical thrombectomy alone is noninferior to combined intravenous thrombolysis plus mechanical thrombectomy for favorable poststroke outcome. DESIGN, SETTING, AND PARTICIPANTS: Investigator-initiated, multicenter, randomized, open-label, noninferiority clinical trial in 204 patients with acute ischemic stroke due to large vessel occlusion enrolled at 23 hospital networks in Japan from January 1, 2017, to July 31, 2019, with final follow-up on October 31, 2019. INTERVENTIONS: Patients were randomly assigned to mechanical thrombectomy alone (n = 101) or combined intravenous thrombolysis (alteplase at a 0.6-mg/kg dose) plus mechanical thrombectomy (n = 103). MAIN OUTCOMES AND MEASURES: The primary efficacy end point was a favorable outcome defined as a modified Rankin Scale score (range, 0 [no symptoms] to 6 [death]) of 0 to 2 at 90 days, with a noninferiority margin odds ratio of 0.74, assessed using a 1-sided significance threshold of .025 (97.5% CI). There were 7 prespecified secondary efficacy end points, including mortality by day 90. There were 4 prespecified safety end points, including any intracerebral hemorrhage and symptomatic intracerebral hemorrhage within 36 hours. RESULTS: Among 204 patients (median age, 74 years; 62.7% men; median National Institutes of Health Stroke Scale score, 18), all patients completed the trial. Favorable outcome occurred in 60 patients (59.4%) in the mechanical thrombectomy alone group and 59 patients (57.3%) in the combined intravenous thrombolysis plus mechanical thrombectomy group, with no significant between-group difference (difference, 2.1% [1-sided 97.5% CI, -11.4% to ∞]; odds ratio, 1.09 [1-sided 97.5% CI, 0.63 to ∞]; P = .18 for noninferiority). Among the 7 secondary efficacy end points and 4 safety end points, 10 were not significantly different, including mortality at 90 days (8 [7.9%] vs 9 [8.7%]; difference, -0.8% [95% CI, -9.5% to 7.8%]; odds ratio, 0.90 [95% CI, 0.33 to 2.43]; P > .99). Any intracerebral hemorrhage was observed less frequently in the mechanical thrombectomy alone group than in the combined group (34 [33.7%] vs 52 [50.5%]; difference, -16.8% [95% CI, -32.1% to -1.6%]; odds ratio, 0.50 [95% CI, 0.28 to 0.88]; P = .02). Symptomatic intracerebral hemorrhage was not significantly different between groups (6 [5.9%] vs 8 [7.7%]; difference, -1.8% [95% CI, -9.7% to 6.1%]; odds ratio, 0.75 [95% CI, 0.25 to 2.24]; P = .78). CONCLUSIONS AND RELEVANCE: Among patients with acute large vessel occlusion stroke, mechanical thrombectomy alone, compared with combined intravenous thrombolysis plus mechanical thrombectomy, failed to demonstrate noninferiority regarding favorable functional outcome. However, the wide confidence intervals around the effect estimate also did not allow a conclusion of inferiority. TRIAL REGISTRATION: umin.ac.jp/ctr Identifier: UMIN000021488.


Assuntos
Fibrinolíticos/administração & dosagem , AVC Isquêmico/tratamento farmacológico , AVC Isquêmico/cirurgia , Trombectomia , Ativador de Plasminogênio Tecidual/administração & dosagem , Doença Aguda , Idoso , Idoso de 80 Anos ou mais , Hemorragia Cerebral/etiologia , Terapia Combinada , Intervalos de Confiança , Feminino , Fibrinolíticos/efeitos adversos , Estado Funcional , Humanos , Infusões Intravenosas , Masculino , Pessoa de Meia-Idade , Índice de Gravidade de Doença , Trombectomia/efeitos adversos , Ativador de Plasminogênio Tecidual/efeitos adversos , Resultado do Tratamento
7.
J Neuroendovasc Ther ; 15(11): 725-729, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-37502267

RESUMO

Objective: A case of posterior cerebral artery (P1 segment) occlusion with consciousness disturbance and Weber's syndrome treated by mechanical thrombectomy is reported. Case Presentation: The patient was a 69-year-old man with consciousness disturbance, left hemiparesis, and anisocoria. MRI revealed acute cerebral infarction in the midbrain and right thalamus. Angiography demonstrated that the right P1 segment was occluded and mechanical thrombectomy was performed. The right P1 segment and its perforator artery, the artery of Percheron (AOP), were both recanalized after the treatment, and the symptoms of perforator occlusion significantly improved. Conclusion: Mechanical thrombectomy for P1 segment occlusion may be effective for improving the symptoms caused by occlusion of its perforator, the AOP.

8.
J Phys Chem Lett ; 11(19): 7996-8001, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32910660

RESUMO

For ligand-protected gold clusters, geometrical differences of gold cores and/or the presence of secondary gold core-ligand interactions influence their unique optical and electronic properties and can, in principle, be detected by spectral changes of gold core vibrations (phonon modes) in ultralow-frequency Raman spectroscopy. We report experimental and theoretical Raman spectra of Au8 clusters protected by phosphine ligands particularly in the "gold cluster fingerprint" region from 50 to 150 cm-1 Raman shift (1.5 to 4.5 terahertz, THz). A characteristic core breathing mode observed at ca. 123 cm-1 was sensitive to differences of core geometries. A new band was found at ca. 150 cm-1, originating from a local strain on a polyhedral gold core caused by weak Au···π interactions. THz Raman spectroscopy can be utilized for metal nanoclusters to visualize core structural changes and Au···π interactions, which cannot be captured by single crystal X-ray analysis.

9.
No Shinkei Geka ; 48(7): 627-632, 2020 Jul.
Artigo em Japonês | MEDLINE | ID: mdl-32694233

RESUMO

We report a case of thrombectomy beyond one day of onset of right middle cerebral artery occlusion. An 82-year-old woman who presented with difficulty in body movements was transferred to our hospital. After admission, left-sided weakness and dysarthria worsened with an National Institutes of Health Stroke Scale of 9. The initial MRI DWI on admission revealed multiple hyper intense signals in the right cerebral hemisphere and MR angiography revealed occlusion of the right internal carotid artery. We performed medical treatment because FLAIR also revealed hyper intense signals in the same lesion as the DWI image, and more than one day had passed since the onset. However, her symptoms worsened and we performed angiography on the next day, and found contrast defects like crab claw at the top of the right internal carotid artery. Even though more than one day had passed since the onset, we assumed that thrombectomy could prevent the worsening of symptoms. The procedure was a success and it resulted in complete reperfusion to the right middle cerebral artery. She showed improvement after the procedure. According to this case, thrombectomy one day from onset could be considered as a treatment option for large vessel occlusion with good collateral flow in the cases resistant to medical treatment.


Assuntos
Acidente Vascular Cerebral , Trombectomia , Idoso de 80 Anos ou mais , Artéria Carótida Interna , Feminino , Humanos , Infarto da Artéria Cerebral Média , Imageamento por Ressonância Magnética , Resultado do Tratamento
10.
World Neurosurg ; 142: 13-16, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32562904

RESUMO

BACKGROUND: Clinical evidence to support the use of mechanical thrombectomy (MT) for posterior cerebral artery P2 segment occlusion (P2O) has not been established, and hemiplegia due to P2O improved by MT to our knowledge has not yet been reported. We report 2 cases of P2O with hemiplegia improved by MT. CASE DESCRIPTION: In case 1, a 68-year-old man was admitted with right hemiplegia and dysesthesia (National Institutes of Health Stroke Scale score 14). Head magnetic resonance imaging showed acute ischemia in the left inferolateral thalamus and posterior limb of the internal capsule. Angiography showed left P2O, which was recanalized after MT. Hemiplegia improved immediately following recanalization, and modified Rankin Scale score at discharge was 0. In case 2, a 69-year-old man was admitted with left hemiplegia and dysesthesia (National Institutes of Health Stroke Scale score 8). Head magnetic resonance imaging showed acute ischemia in the right inferolateral thalamus and posterior limb of the internal capsule. Angiography showed right P2O, which was recanalized after MT, as in case 1. His symptoms resolved completely. CONCLUSIONS: P2O may cause severe motor deficit. In such cases, MT may contribute to safely improving patients' deficits.


Assuntos
Transtornos Cerebrovasculares/cirurgia , Debilidade Muscular/cirurgia , Artéria Cerebral Posterior/cirurgia , Trombectomia/métodos , Idoso , Transtornos Cerebrovasculares/complicações , Transtornos Cerebrovasculares/diagnóstico por imagem , Humanos , Masculino , Debilidade Muscular/diagnóstico por imagem , Debilidade Muscular/etiologia , Artéria Cerebral Posterior/diagnóstico por imagem
11.
Dev Growth Differ ; 62(4): 214-222, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32275061

RESUMO

Missense mutations of the RET gene have been identified in both multiple endocrine neoplasia (MEN) type 2A/B and Hirschsprung disease (HSCR: congenital absence of the enteric nervous system, ENS). Current consensus holds that MEN2A/B and HSCR are caused by activating and inactivating RET mutations, respectively. However, the biological significance of RET missense mutations in vivo has not been fully elucidated. In the present study, we introduced one MEN2B-associated (M918T) and two HSCR-associated (N394K and Y791F) RET missense mutations into the corresponding regions of the mouse Ret gene by genome editing (RetM919T , RetN396K and RetY792F ) and performed histological examinations of Ret-expressing tissues to understand the pathogenetic impact of each mutant in vivo. RetM919T/+ mice displayed MEN2B-related phenotypes, including C-cell hyperplasia and abnormal enlargement of the primary sympathetic ganglia. Similar sympathetic phenotype was observed in RetM919T/- mice, demonstrating a strong pathogenetic effect of the Ret M918T by a single-allele expression. In contrast, no abnormality was found in the ENS of mice harboring the Ret N394K or Y791F mutation. Most surprisingly, single-allele expression of RET N394K or Y791F was sufficient for normal ENS development, indicating that these RET mutants exert largely physiological function in vivo. This study reveals contrasting pathogenetic effects between MEN2B- and HSCR-associated RET missense mutations, and suggests that some of HSCR-associated RET missense mutations are by themselves neither inactivating nor pathogenetic and require involvement of other gene mutations for disease expressivity.


Assuntos
Doença de Hirschsprung/genética , Neoplasia Endócrina Múltipla Tipo 2b/genética , Mutação de Sentido Incorreto , Mutação Puntual , Proteínas Proto-Oncogênicas c-ret/genética , Animais , Feminino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos ICR
12.
Angew Chem Int Ed Engl ; 58(8): 2443-2447, 2019 Feb 18.
Artigo em Inglês | MEDLINE | ID: mdl-30614159

RESUMO

It is well known that alkynes act as π-acids in the formation of complexes with metals. We found unprecedented attractive Au-π interactions in diacetylene-modified [core+exo]-type [Au8 ]4+ clusters. The 4-phenyl-1,3-butadiynyl-modified cluster has unusually short Au-Cα distances in the crystal structure, revealing the presence of attractive interactions between the coordinating C≡C moieties and the neighboring bitetrahedral Au6 core, which is further supported by IR and NMR spectra. Such weak interactions are not found in mono-acetylene-modified clusters, which indicates that they are specific for diacetylenic ligands. The attractive Au-π interactions are likely associated with the low energy of the π* orbital in the diacetylenic moieties, into which the valence electrons of the gold core may be back donated. The [Au8 ]4+ clusters show clear red-shifts of >10 nm with respect to the corresponding mono-acetylenic clusters in UV/Vis absorption bands, which indicates substantial electronic perturbation effects of the Au-π interactions.

13.
Acc Chem Res ; 51(12): 3125-3133, 2018 12 18.
Artigo em Inglês | MEDLINE | ID: mdl-30427180

RESUMO

Over recent years, research on the structures and properties of ligand-protected gold cluster molecules has gained significant interest. The crystal structure information accumulated to date has revealed the structural preference to adopt closed polyhedral geometries, but the use of multidentate ligands sometimes leads to the formation of exceptional structures. This Account describes results of our studies on diphosphine-coordinated [core+ exo]-type gold clusters featuring extra gold atoms outside the polyhedral cores, highlighting (1) their distinct optical properties due to the unique electronic structures generated by the exo gold atoms and (2) electronic/attractive ligand-cluster interactions that cause definite perturbation effects on the cluster properties. Subnanometer gold clusters with [core+ exo]-type geometries (nuclearity = 6, 7, 8, and 11) commonly displayed single absorption bands in the visible region, which are distinct in patterns from those of conventional polyhedral-only homologues. Theoretical studies demonstrated that the exo gold atoms are critically involved in the generation of unique electronic structures characterized by the HOMO-LUMO transitions with dominant oscillator strengths, leading to the appearance of the isolated absorption bands. On the basis of the frontier orbital distributions, the HOMO and LUMO were shown to be localized around the polyhedral cores and exo gold atoms, respectively. Therefore, the HOMO-LUMO transitions responsible for the visible absorptions occur in the core → exo direction. The HOMO-LUMO gap energies showed no clear trends with respect to the nuclearity (size), indicating that the individual geometric features of the inorganic framework primarily govern the clusters' electronic structures and properties. Systematic studies using octagold clusters bearing various anionic coligands revealed that electronic or attractive interactions between the gold framework and ligand functionalities, such as π-electron systems and heteroatoms, cause substantial perturbations of the wavelength of the visible absorption band due to the HOMO-LUMO transitions. Especially, significant red shifts were observed as a result of the electronic coupling with specific π-resonance contributors. It was also found that the orientation of aromatic rings around the inorganic framework is a factor that affects the cluster photoluminescence. These findings demonstrate the utility of the ligand moieties surrounding the gold frameworks for fine-tuning of the optical properties. During these studies, unusual but definite attractive interactions between the gold framework and C-H groups of the diphosphine ligand were found in the hexagold clusters. On the basis of careful crystallographic and NMR analyses, these interactions were deemed as a certain kind of M···H hydrogen bonds, which critically affect the maintenance of the cluster framework. Such unique interaction activities are likely due to the valence electrons in the gold framework, which serve as the hydrogen-bond acceptor for the unfunctionalized C-H groups. Overall, these observations imply the uniqueness of the ligand-cluster interface associated with the partially oxidized gold entities, which may expand the scope of ligand-protected clusters toward various applications.

14.
Nat Commun ; 8(1): 576, 2017 09 18.
Artigo em Inglês | MEDLINE | ID: mdl-28924211

RESUMO

It is well known that various transition elements can form M···H hydrogen bonds. However, for gold, there has been limited decisive experimental evidence of such attractive interactions. Herein we demonstrate an example of spectroscopically identified hydrogen bonding interaction of C-H units to Au atoms in divalent hexagold clusters ([Au6]2+) decorated by diphosphine ligands. X-ray crystallography reveals substantially short Au-H/Au-C distances to indicate the presence of attractive interactions involving unfunctionalized C-H moieties. Solution 1H and 13C NMR signals of the C-H units appear at considerably downfield regions, indicating the hydrogen-bond character of the interactions. The Au···H interactions are critically involved in the ligand-cluster interactions to affect the stability of the cluster framework. This work demonstrates the uniqueness and potential of partially oxidised Au cluster moieties to participate in non-covalent interaction with various organic functionalities, which would expand the scope of gold clusters.Many transition metals can form hydrogen bonds to organic species, but experimental evidence for Au is still lacking. Here, the authors obtain crystallographic and NMR spectroscopic evidence of hydrogen bonding between C-H groups and Au atoms of gold clusters, suggesting that non-covalent interactions may play a role in gold cluster catalysis.

15.
J Phys Chem Lett ; 7(21): 4267-4274, 2016 Nov 03.
Artigo em Inglês | MEDLINE | ID: mdl-27735186

RESUMO

Recent advances in the crystal structure determination of ligand-protected metal clusters have revealed that their electronic structures and optical features are essentially governed by the nuclearity and geometries of the inorganic frameworks. In this Perspective, we point out the definite effects of the exterior ligand moieties on the properties of small gold clusters. On the basis of systematic experimental studies on the optical properties of Au8 and Au13 clusters with various anionic ligands, it was shown that not only the "through-bond" electronic effects of coordinating atoms but also the nonbonding interaction with neighboring heteroatoms and the electronic coupling with π-systems cause substantial perturbations. We also suggest that the steric rigidity of the ligand environments affects their photoluminescence efficiencies. These findings imply the feasibility of the facile modulation of the cluster properties through the appropriate choice of ligand modules, which may lead to the evolution of novel cluster-based materials with unique properties and functions.

16.
Phys Chem Chem Phys ; 18(28): 19433-9, 2016 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-27378218

RESUMO

In the recent development of structurally defined ligand-stabilized gold clusters, it has been revealed that not only the inorganic units but also the surrounding organic ligands substantially affect their electronic/optical properties. In this work, a series of core + exo type Au8 clusters decorated by dppp (Ph2P(CH2)3PPh2) and arylthiolate ligands ([Au8(dppp)4(SR)2](2+), 1-5) were synthesized, and their optical properties were studied in order to gain insights into the perturbation effects of the organic ligands. 1-5 showed visible absorption and photoluminescence emission bands at longer wavelengths compared to their chloro- and acetylide-modified analogues, suggesting the contribution of weak non-bonding interactions of the Au framework with the ligand heteroatoms. Upon acid treatment, 2- and 4-pyridinethiolate clusters (R = Py, 2 and 4) showed larger red shifts of the absorption and emission bands than the 3-pyridyl isomer (3), implying the involvement of the resonance structures of the SPy units. On the other hand, all regioisomers (2-4) showed large photoluminescence enhancements upon pyridine protonation. X-ray crystallographic and NMR analyses of 4 and its protonated form (4') showed that the electron-deficient pyridinium rings of 4' form π-stacks with neighbouring phenyl groups of dppp, suggesting that the orientation of the surface aromatics is a plausible factor governing the emission efficiency. These observations provide examples of successful modulation of optical properties of small gold clusters through the electronic and/or steric perturbation by the proximal organic ligands, highlighting the importance of the ligand design in the fine tuning of cluster properties directed for optical chemosensors and luminescent materials.

17.
Surg Neurol Int ; 6: 182, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26677416

RESUMO

BACKGROUND: Compared to those found in the vertebrobasilar system, intracranial dissection in the anterior circulation is relatively rare, especially in the anterior cerebral artery (ACA). Moreover, only several cases of ACA dissection that underwent endovascular treatment have been reported. Here we present a rare case of gradually developing ACA dissecting aneurysm causing cerebral infarction, successfully treated by stent-assisted coil embolization. CASE DESCRIPTION: A 36-year-old man was admitted with sudden right hemiparesis. Diffusion-weighted magnetic resonance (MR) imaging showed cerebral infarction in the left ACA territory, and MR angiography showed segmental stenosis at the A2 portion of the left ACA. Three-dimensional digital subtraction angiogram showed segmental dilatation and stenosis at the left A2 portion. We diagnosed ACA dissection causing acute cerebral infarction and treated the patient conservatively. Five months after the onset, the dissecting artery at the left A2 portion formed a gradually dilating aneurysm, suggesting increased risk for aneurysmal rupture. We attempted endovascular treatment entailing coil embolization of an aneurysm while preserving the left A2 with stent assistance. The patient remained neurologically stable 6 months after the procedure. CONCLUSIONS: Although there are few reported cases of ACA dissection where endovascular treatment was attempted, we consider stent-assisted embolization for gradually developing ACA dissecting aneurysm as an alternative method to prevent bleeding and recurrent infarction.

18.
Jpn J Antibiot ; 68(3): 151-87, 2015 Jun.
Artigo em Japonês | MEDLINE | ID: mdl-26349116

RESUMO

This is an integrated summary of the results obtained from a 3-decade multicenter study on bacteria isolated from surgical infections in Japan between July 1982 and March 2012. During the 3-decade study, 11,196 strains were isolated from 4,787 patients consisting of 2,132 patients with primary infection and 2,655 patients with surgical site infection. Almost half of the primary infection was peritonitis, which accounted for 42.3%-55.5%. In contrast, most of the surgical site infection was wound infection, which accounted for 49.3%-66.1%. The most commonly isolated bacteria throughout three decades were Escherichia coli (1,164 strains), Enterococcus faecalis (842), Staphylococcus aureus (833), Pseudomonas aeruginosa (706), Bacteroides fragilis (705), Klebsiella pneumoniae (498), Enterobacter cloacae (391) and coagulase-negative staphylococci (CNS) (325). Overall, S. aureus and CNS had sensitivity for vancomycin, whose MIC90s were 0.78 to 3.13 µg/mL; E. faecalis had sensitivity for vancomycin and imipenem, whose MIC90s were 0.78-4 µg/mL; E coli, E. cloacae, K. pneumoniae, and B. fragilis had preferable sensitivity for imipenem. No antibacterial agents had a long-term good activity (e.g. MIC90 < 2 µg/mL) for P aeruginosa and Bilophila wadsworthia. Among antibacterial agents tested, ciprofloxacin had most bactericidal activity for P. aeruginosa; its MIC90 varied from 0.5 to 8 µg/mL. The MIC90s of all antibacterial agents tested except levofloxacin and minocycline were at least 128 µg/mL for B. wadsworthia. S. aureus accounted for approximately 20% to 60% of bacteria isolated after clean operation. Overall, at least 55% of the bacteria isolated after clean operation consisted of S. aureus, CNS, E. faecalis, E. coli, E. cloacae, K. pneunoniae, P. aeruginosa, B. fragilis, and B. wadsworthia throughout three decades. However, the percentage of other Gram-positive and negative bacteria increased with the worse of sterile condition in surgical operation. E. faecalis tended to be most commonly isolated from patients having host-compromised factors including carcinoma, diabetes, anticancer agents, steroids, immunosuppressants, and radiation, while E. coli was commonly isolated from patients having no such factors. Two-drug-resistant P. aeruginosa was first isolated in 1987, thereafter was frequently isolated, and reached 69 strains for 30 years. Three-drug-resistant P. aeruginosa was isolated in 1990, 1996, and 1998 to reach 5 strains, but not isolated in remaining 13 years. Methicillin-resistant S. aureus was highly frequently isolated between 1988 and 1991. Subsequently, the isolation frequency declined, sometimes increased in 1998, 2005, and 2006, and thereafter maintained lower levels by 2011.


Assuntos
Anti-Infecciosos/farmacologia , Bactérias/efeitos dos fármacos , Bactérias/isolamento & purificação , Infecção da Ferida Cirúrgica/microbiologia , Farmacorresistência Bacteriana , Humanos , Testes de Sensibilidade Microbiana , Fatores de Tempo
19.
Jpn J Antibiot ; 68(2): 85-104, 2015 Apr.
Artigo em Japonês | MEDLINE | ID: mdl-26182813

RESUMO

From October 2010 to September 2011, we collected the specimen from 361 patients with lower respiratory tract infections in 16 institutions in Japan, and investigated the susceptibilities of isolated bacteria to various antibacterial agents and patients' characteristics. All of 399 strains that were isolated from specimen (mainly from sputum) and assumed to be bacteria causing in infection, were examined. The isolated bacteria were: Staphylococcus aureus 70, Streptococcus pneumoniae 65, Haemophilus influenzae 72, Pseudomonas aeruginosa (non-mucoid) 47, P. aeruginosa (mucoid) 14, Klebsiella pneumoniae 30, and Moraxella catarrhalis 39. Of 70 S. aureus strains, those with 2 µg/mL or less of MIC of oxacillin (methicillin-susceptible S. aureus: MSSA) and those with 4 µg/mL or more of MIC of oxacillin (methicillin-resistant S. aureus: MRSA) were 45 (64.3%) and 25 (35.7%) strains, respectively. Against MSSA, imipenem had the most potent antibacterial activity and inhibited the growth of all strains at 0.063 µg/mL or less. Against MRSA, vancomycin and arbekacin showed the potent activity and inhibited the growth of all the strains at 2 µg/mL. Linezolid also showed the great activity and inhibited the growth of all the strains at 2 µg/mL. Carbapenems and penems showed the most potent activities against S. pneumoniae and panipenem inhibited the growth of all the strains at 0.125 µg/mL. Imipenem and faropenem also had a preferable activity and inhibited the growth of all the strains at 0.5 and 1 µg/mL, respectively. In contrast, there were high-resistant strains (MIC: > 128 µg/mL) for erythromycin (44.6%) and clindamycin (24.6%). Against H. influenzae, levofloxacin showed the most potent activity and its MIC90 was 0.063 µg/mL or less. Meropenem showed the most potent activity against P. aeruginosa (mucoid) and its MIC90 was 0.5 µg/mL. Against the non-mucoid type of P. aeruginosa, tobramycin had the most potent activity and its MIC90 was 2 µg/mL. Against K. pneumoniae, cefozopran had the most potent activity and inhibited the growth of all the strains at 0.063 µg/mL or less. All the antibacterial agents except ampicillin generally showed a potent activity against M. catarrhalis and the MIC90 of them were 2 µg/mL or less. The majority number (54.8%) of the patients with respiratory infection was aged 70 years or older. Bacterial pneumonia and chronic bronchitis accounted for 58.7% and 24.4% of all the respiratory infection, respectively. The bacteria frequently isolated from the patients with bacterial pneumonia were S. aureus (20.6%), S. pneumoniae (18.0%), H. influenzae (13.6%), and P. aeruginosa (13.6%). S. aureus (17.2%), H. influenzae (20.2%), and P. aeruginosa (17.2%) also were frequently isolated from the patients with chronic bronchitis. The bacteria frequently isolated from the patients were S. pneumoniae (20.0%) and H. influenzae (20.0%) before administration of the antibacterial agents. The bacteria frequently isolated from the patients previously treated with cephems were S. aureus and H. influenzae, and the isolation frequencies were 25.0% and 20.0%, respectively. The bacteria frequently isolated from the patients previously treated with macrolides were P. aeruginosa and H. influenzae, the isolation frequencies were 25.9% and 22.2%, respectively.


Assuntos
Antibacterianos/farmacologia , Bactérias/efeitos dos fármacos , Infecções Respiratórias/microbiologia , Adulto , Idoso , Bactérias/isolamento & purificação , Humanos , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade
20.
Jpn J Antibiot ; 68(2): 105-24, 2015 Apr.
Artigo em Japonês | MEDLINE | ID: mdl-26182814

RESUMO

From October 2011 to September 2012, we collected the specimen from 316 patients with lower respiratory tract infections in 16 institutions in Japan, and investigated the susceptibilities of isolated bacteria to various antibacterial agents and patients' characteristics. All of 357 strains that were isolated from specimen (mainly from sputum) and assumed to be bacteria causing in infection, were examined. The isolated bacteria were: Staphylococcus aureus 51, Streptococcus pneumoniae 73, Haemophilus influenzae 88, Pseudomonas aeruginosa (non-mucoid) 34, P. aeruginosa (mucoid) 9, Klebsiella pneumoniae 21, and Moraxella catarrhalis 33. Of 51 S. aureus strains, those with 2 µg/mL or less of MIC of oxacillin (methicillin-susceptible S. aureus: MSSA) and those with 4 µg/mL or more of MIC of oxacillin (methicillin-resistant S. aureus: MRSA) were 31 (60.8%) and 20 (39.2%) strains, respectively. Against MSSA, imipenem had the most potent antibacterial activity and inhibited the growth of all strains at 0.063 µg/mL or less. Against MRSA, vancomycin showed the potent activity and inhibited the growth of all the strains at 1 µg/mL. Linezolid also showed the great activity and inhibited the growth of all the strains at 2 µg/mL. Carbapenems and penems showed the most potent activities against S. pneumoniae and panipenem inhibited the growth of all the strains at 0.125 µg/mL. Imipenem and faropenem also had a preferable activity and inhibited the growth of all the strains at 0.5 and 1 µg/mL, respectively. In contrast, there were high-resistant strains (MIC: > 128 µg/mL) for erythromycin (53.4%) and clindamycin (3 5.6%). Against H. influenzae, levofloxacin showed the most potent activity and its MIC90 was 0.063 µg/mL or less. Ciprofloxacin showed the most potent activity against P. aeruginosa (mucoid) and inhibited the growth of all the strains at 2 µg/mL or less. Against the non-mucoid type of P. aeruginosa, tobramycin had the most potent activity and its MIC90 was 2 µg/mL. Against K. pneumoniae, imipenem had the most potent activity and inhibited the growth of all the strains at 0.125 µg/mL. All the antibacterial agents except ampicillin generally showed a potent activity against M catarrhalis and the MIC90 of them were 2 µg/mL or less. The majority number (52.9%) of the patients with respiratory infection was aged 70 years or older. Bacterial pneumonia and chronic bronchitis accounted for 59.2% and 19.3% of all the respiratory infection, respectively. The bacteria frequently isolated from the patients with bacterial pneumonia were S. aureus (17.8%), S. pneumoniae (21.6%), and H. influenzae (16.9%). H. influenzae (36.8%) and S. pneumoniae (22.1%) also were frequently isolated from the patients with chronic bronchitis. The bacteria frequently isolated from the patients were S. pneumoniae (23.2%) and H. influenzae (27.3%) before administration of the antibacterial agents. The bacteria frequently isolated from the patients previously treated with cephems were H. influenzae and P. aeruginosa, and the isolation frequencies were 38.5% and 23.1%, respectively. The bacteria frequently isolated from the patients previously treated with macrolides were H. influenzae, the isolation frequencies were 30.0%.


Assuntos
Antibacterianos/farmacologia , Bactérias/efeitos dos fármacos , Infecções Respiratórias/microbiologia , Adulto , Idoso , Bactérias/isolamento & purificação , Humanos , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade
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