Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 18 de 18
Filtrar
Mais filtros








Base de dados
Intervalo de ano de publicação
1.
Beilstein J Org Chem ; 20: 1560-1571, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39015618

RESUMO

An electrocatalytic hydrogenation of cyanoarenes, nitroarenes, quinolines, and pyridines using a proton-exchange membrane (PEM) reactor was developed. Cyanoarenes were then reduced to the corresponding benzylamines at room temperature in the presence of ethyl phosphate. The reduction of nitroarenes proceeded at room temperature, and a variety of anilines were obtained. The quinoline reduction was efficiently promoted by adding a catalytic amount of p-toluenesulfonic acid (PTSA) or pyridinium p-toluenesulfonate (PPTS). Pyridine was also reduced to piperidine in the presence of PTSA.

2.
Beilstein J Org Chem ; 18: 1055-1061, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36105727

RESUMO

Electrochemical hydrogenation of enones using a proton-exchange membrane reactor is described. The reduction of enones proceeded smoothly under mild conditions to afford ketones or alcohols. The reaction occurred chemoselectively with the use of different cathode catalysts (Pd/C or Ir/C).

3.
Int J Cardiol Heart Vasc ; 33: 100742, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33732869

RESUMO

BACKGROUND: Sustained new-onset atrial fibrillation (AF) in the intensive care unit has been reported to be associated with poor outcomes. However, in critical illness, whether rhythm-control therapy can achieve sinus rhythm (SR) restoration is unknown. This study aimed to assess the impact of rhythm-control therapy on SR restoration for new-onset AF in critically ill patients. METHODS: This post-hoc analysis of a prospective multicenter observational study involving 32 Japan intensive care units compared patients with and without rhythm-control therapy for new-onset atrial fibrillation (AF) and conducted a multivariable analysis using Cox proportional hazards regression analysis including rhythm-control therapy as a time-varying covariate for SR restoration. RESULTS: Of 423 new-onset AF patients, 178 patients (42%) underwent rhythm-control therapy. Among those patients, 131 (31%) underwent rhythm-control therapy within 6 h after AF onset. Magnesium sulphate was the most frequently used rhythm-control drug. The Cox proportional hazards model for SR restoration showed that rhythm-control therapy had a significant positive association with SR restoration (adjusted hazard ratio: 1.46; 95% confidence interval: 1.16-1.85). However, the rhythm-control group had numerically higher hospital mortality than the non-rhythm-control group (31% vs. 23%, p = 0.09). CONCLUSIONS: Rhythm-control therapy for new-onset AF in critically ill patients was associated with SR restoration. However, patients with rhythm-control therapy had poorer prognosis, possibly due to selection bias. These findings may provide important insight for the design and feasibility of interventional studies assessing rhythm-control therapy in new-onset AF.

4.
J Cardiothorac Vasc Anesth ; 35(9): 2768-2771, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-32888803

RESUMO

Kounis syndrome is an anaphylactic reaction leading to acute coronary syndrome. The acute treatment of anaphylaxis is epinephrine; however, epinephrine may cause coronary vasoconstriction, reduce coronary blood flow, increase myocardial oxygen demand, and worsen myocardial ischemia. On the other hand, coronary vasodilation, a treatment for acute coronary syndrome, can aggravate hypotension in patients with anaphylaxis. Herein, the authors report a case of type II Kounis syndrome, with vasospasm in a patient with coronary disease, requiring the administration of epinephrine and a coronary vasodilator for resuscitation. The authors administered intravenous epinephrine continuously from lower dosages and performed delicate titration. The coronary vasodilator nicorandil, which has little effect on hemodynamics, also was administered. These treatments improved hemodynamics without complications. Circulatory management that considers both anaphylaxis and coronary lesions is crucial to improve prognosis in this syndrome.


Assuntos
Alérgenos/efeitos adversos , Anafilaxia , Vasoespasmo Coronário , Síndrome de Kounis , Anafilaxia/induzido quimicamente , Anafilaxia/diagnóstico , Anafilaxia/tratamento farmacológico , Vasoespasmo Coronário/induzido quimicamente , Vasoespasmo Coronário/diagnóstico , Vasoespasmo Coronário/tratamento farmacológico , Eletrocardiografia , Epinefrina/uso terapêutico , Humanos , Síndrome de Kounis/diagnóstico , Síndrome de Kounis/tratamento farmacológico , Vasodilatadores/uso terapêutico
5.
Biosci Biotechnol Biochem ; 84(10): 2028-2036, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32543982

RESUMO

Eukaryotic in vitro translation systems require large numbers of protein and RNA components and thereby rely on the use of cell extracts. Here we established a new in vitro translation system based on rice callus extract (RCE). We confirmed that RCE maintains its initial activity even after five freeze-thaw cycles and that the optimum temperature for translation is around 20°C. We demonstrated that the RCE system allows the synthesis of hERG, a large membrane protein, in the presence of liposomes. We also showed that the introduction of a bicistronic mRNA based on 2A peptide to RCE allowed the production of two distinct proteins from a single mRNA. Our new method thus facilitates laboratory-scale production of cell extracts, making it a useful tool for the in vitro synthesis of proteins for biochemical studies.


Assuntos
Oryza/química , Extratos Vegetais/metabolismo , Biossíntese de Proteínas , Sistema Livre de Células/metabolismo , RNA Mensageiro/genética
6.
Angew Chem Int Ed Engl ; 59(20): 7803-7807, 2020 May 11.
Artigo em Inglês | MEDLINE | ID: mdl-32077555

RESUMO

The first electrochemical dehydrogenative C-S bond formation leading to thienoacene derivatives is described. Several thienoacene derivatives were synthesized by dehydrogenative C-H/S-H coupling. The addition of n Bu4 NBr, which catalytically promoted the reaction as a halogen mediator, was essential.

7.
Medicine (Baltimore) ; 98(28): e16452, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31305476

RESUMO

Endotoxemia often occurs in patients with gram-positive infections. The possible mechanism is thought to be bacterial translocation after enterocyte hypoperfusion injury. However, the association between endotoxemia and enterocyte injury among patients with gram-positive septic shock has never been assessed. The aim of this study was to evaluate the association between endotoxemia and enterocyte injury in gram-positive septic shock patients and to evaluate the association among endotoxemia, subsequent clinical course, and other related factors.This was a posthoc analysis of a prospective observational study that evaluated the capability of intestinal fatty acid-binding protein (I-FABP), an indicator of enterocyte injury, to predict mortality. Among 57 patients in septic shock, those whose causative microorganisms were gram positive were included. The correlation between endotoxin activity (EA), which indicates endotoxemia, and I-FABP levels upon admission to the intensive care unit (ICU), the clinical course, and other related factors were evaluated.A total of 21 patients were examined. One-third of the patients presented with high EA levels at the time of ICU admission. However, there was no significant correlation between EA and I-FABP levels (Spearman ρ = 0.002, P = .993). Additionally, high EA levels were not associated with abdominal complications after ICU admission or mortality. Similarly, high EA levels were not associated with severity scores, inotropic scores, or lactate levels upon ICU admission, which were previously reported to be factors related to high EA levels.In this posthoc analysis, no correlation was observed between endotoxemia and enterocyte injury among patients in gram-positive septic shock. Additionally, high EA levels were not associated with the clinical course and reported factors related to endotoxemia. Although our results need to be validated in a large prospective cohort study, hypoperfusion enterocyte injury might not be a cause of endotoxemia in these patients. Thus, if there is no correlation between EA and I-FABP levels, other mechanisms that induce high EA levels among patients with gram-positive septic shock should be elucidated.


Assuntos
Endotoxemia/sangue , Proteínas de Ligação a Ácido Graxo/sangue , Infecções por Bactérias Gram-Positivas/sangue , Infecções por Bactérias Gram-Positivas/mortalidade , Choque Séptico/sangue , Choque Séptico/mortalidade , Idoso , Idoso de 80 Anos ou mais , Biomarcadores/sangue , Cuidados Críticos , Progressão da Doença , Endotoxemia/mortalidade , Endotoxemia/terapia , Enterócitos/metabolismo , Feminino , Infecções por Bactérias Gram-Positivas/terapia , Humanos , Masculino , Prognóstico , Estudos Prospectivos , Choque Séptico/terapia
8.
Reg Anesth Pain Med ; 44(3): 326-332, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30674696

RESUMO

BACKGROUND AND OBJECTIVES: This randomized, controlled, double-blind trial compared the effectiveness of levobupivacaine delivery of a programmed intermittent paravertebral bolus with a continuous paravertebral infusion. METHODS: Thirty-two consecutively enrolled patients who underwent unilateral video-assisted thoracic surgery were randomized to receive either a programmed intermittent paravertebral bolus of 10 mL of 0.2% levobupivacaine every 2 hours (Bolus group, n=16) or a continuous paravertebral infusion of 0.2% levobupivacaine at 5 mL/hour (Infusion group, n=16) after the operation. Postoperatively, after injection of 20 mL of 0.25% levobupivacaine through the paravertebral catheter, a mechanical infusion pump was set depending on the assigned group. The primary efficacy outcome was the number of anesthetized dermatomes 24 hours after the initial bolus of levobupivacaine. The secondary efficacy outcomes included the number of anesthetized dermatomes at other time points, pain at rest and coughing, additional analgesic use and patient acceptance of the analgesic technique. Arterial levobupivacaine concentration was measured to ensure safety. P<0.05 was considered statistically significant. RESULTS: The mean (95% CI) number of anesthetized dermatomes 24 hours after the initial bolus of levobupivacaine was significantly larger among subjects receiving programmed intermittent bolus (n=16) compared with those receiving continuous infusion (n=16; 6.8 (5.7-7.9) vs 3.1 (2.0-4.2); p<0.001). The arterial levobupivacaine concentration did not reach a toxic level. CONCLUSIONS: The programmed intermittent paravertebral bolus of levobupivacaine provided a wider dermatomal spread of sensory block than continuous paravertebral infusion with an identical hourly dose of levobupivacaine. TRIAL REGISTRATION NUMBER: UMIN000022532.

9.
Shock ; 50(5): 530-537, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-29432382

RESUMO

A correlation between sublingual and intestinal mucosa microcirculation, and ischemic necrosis of the tongue as a sign of poor prognosis has been reported. However, an association between tongue ischemia and intestinal health and subsequent outcome has never been studied. This preliminary prospective observational study evaluated the association between macroscopic tongue ischemia and enterocyte injury and poor outcome in patients with septic shock. In this study, 57 adults with septic shock on mechanical ventilators were enrolled. Macroscopic tongue ischemia upon intensive care unit (ICU) admission was assessed by two independent intensivists. We used intestinal fatty-acid binding protein (I-FABP) as a biomarker of enterocyte injury and evaluated the association with tongue ischemia. Demographic variables, risk factor data, and 28-day mortality information were also collected. Compared with patients with normal tongues (n = 45), those with ischemic tongues (n = 12) had a significantly higher Acute Physiology and Chronic Health Evaluation II score (29.0 [25.0-34.0] vs. 36.5 [30.5-44.5], P = 0.017), lactate level (2.8 [2.0-5.0] vs. 9.3 [4.5-10.6], P = 0.002), and I-FABP level (1.9 [0.8-4.0] vs. 54.4 [19.5-159.3], P < 0.001) and the all-cause 28-day mortality was significantly higher (7% vs. 83%, P < 0.001). In conclusion, macroscopic tongue ischemia at ICU admission was associated with enterocyte injury and poor outcome in patients with septic shock. Although there is a disadvantage in that assessment of the tongue was subjective, tongue ischemia could be used to gauge the severity of intestinal injury and to estimate poor outcome in the clinical setting.


Assuntos
Enterócitos/patologia , Isquemia/metabolismo , Isquemia/patologia , Choque Séptico/patologia , Doenças da Língua/metabolismo , Doenças da Língua/patologia , Língua/metabolismo , Língua/patologia , Idoso , Idoso de 80 Anos ou mais , Proteínas de Ligação a Ácido Graxo/metabolismo , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Choque Séptico/metabolismo
10.
J Crit Care ; 42: 92-100, 2017 12.
Artigo em Inglês | MEDLINE | ID: mdl-28710988

RESUMO

PURPOSE: We sought to evaluate the levels of intestinal fatty acid-binding protein (I-FABP), a biomarker of enterocyte injury, as a predictor of 28-day mortality and bowel ischemia in septic shock patients. MATERIAL AND METHODS: In this preliminary prospective observational study, 57 adult septic shock patients under mechanical ventilation were enrolled. Serum I-FABP levels and prognostic biomarkers were recorded upon intensive care unit (ICU) admission. RESULTS: The overall 28-day mortality rate of participants was 23% (13/57). Non-survivors displayed significantly higher lactate (p=0.009), I-FABP (p=0.012), and N-terminal pro-B-type natriuretic peptide (p=0.039) levels compared to survivors. Only I-FABP was associated with 28-day mortality (odds ratio, 1.036; 95% confidence interval, 1.003-1.069; p=0.031) in a multiple logistic regression analysis adjusted for the Acute Physiology and Chronic Health Evaluation II score. When divided into low and high I-FABP groups based on the optimum cut-off value of 19.0ng/mL for predicting 28-day mortality, high-I-FABP patients had a significantly higher incidence of non-occlusive mesenteric ischemia (NOMI) (2% [1/43] vs 29% [4/14]; p=0.011). CONCLUSIONS: I-FABP level at ICU admission can serve as a predictor of 28-day mortality in septic shock patients and is associated with the incidence of NOMI.


Assuntos
Proteínas de Ligação a Ácido Graxo/metabolismo , Isquemia Mesentérica/mortalidade , Choque Séptico/mortalidade , Idoso , Biomarcadores/metabolismo , Cuidados Críticos , Feminino , Humanos , Ácido Láctico/sangue , Ácido Láctico/metabolismo , Masculino , Isquemia Mesentérica/sangue , Pessoa de Meia-Idade , Peptídeo Natriurético Encefálico/metabolismo , Razão de Chances , Fragmentos de Peptídeos/metabolismo , Prognóstico , Estudos Prospectivos , Respiração Artificial/mortalidade , Choque Séptico/sangue
11.
PLoS One ; 10(11): e0142206, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26529243

RESUMO

Lipocalin-type prostaglandin D synthase (L-PGDS) is a member of the lipocalin superfamily, which is composed of secretory transporter proteins, and binds a wide variety of small hydrophobic molecules. Using this function, we have reported the feasibility of using L-PGDS as a novel drug delivery vehicle for poorly water-soluble drugs. In this study, we show the development of a drug delivery system using L-PGDS, one that enables the direct clinical use of 7-ethyl-10-hydroxy-camptothecin (SN-38), a poorly water-soluble anti-cancer drug. In the presence of 2 mM L-PGDS, the concentration of SN-38 in PBS increased 1,130-fold as compared with that in PBS. Calorimetric experiments revealed that L-PGDS bound SN-38 at a molecular ratio of 1:3 with a dissociation constant value of 60 µM. The results of an in vitro growth inhibition assay revealed that the SN-38/L-PGDS complexes showed high anti-tumor activity against 3 human cancer cell lines, i.e., Colo201, MDA-MB-231, and PC-3 with a potency similar to that of SN-38 used alone. The intravenous administration of SN-38/L-PGDS complexes to mice bearing Colo201 tumors showed a pronounced anti-tumor effect. Intestinal mucositis, which is one of the side effects of this drug, was not observed in mice administered SN-38/L-PGDS complexes. Taken together, L-PGDS enables the direct usage of SN-38 with reduced side effects.


Assuntos
Antineoplásicos , Camptotecina/análogos & derivados , Portadores de Fármacos , Oxirredutases Intramoleculares , Lipocalinas , Animais , Antineoplásicos/farmacocinética , Antineoplásicos/farmacologia , Camptotecina/farmacocinética , Camptotecina/farmacologia , Linhagem Celular Tumoral , Portadores de Fármacos/farmacocinética , Portadores de Fármacos/farmacologia , Ensaios de Seleção de Medicamentos Antitumorais , Feminino , Humanos , Oxirredutases Intramoleculares/farmacocinética , Oxirredutases Intramoleculares/farmacologia , Irinotecano , Lipocalinas/farmacocinética , Lipocalinas/farmacologia , Camundongos , Camundongos Endogâmicos BALB C , Solubilidade
12.
J Intensive Care ; 3: 42, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26473035

RESUMO

BACKGROUND: The urinary albumin/creatinine ratio (ACR) is a significant neurologic prognostic predictor in patients with aneurysmal subarachnoid hemorrhage (SAH). B-type natriuretic peptide (BNP) plays an important role in body fluid regulation in patients with SAH. The present study was performed to determine whether ACR was independent predictor for unfavorable neurological outcome and ACR was associated with increased N-terminal pro-BNP (NT-pro-BNP) after SAH. METHODS: We studied 61 patients undergoing surgery who were admitted within 48 h after aneurysmal SAH onset between July 2008 and June 2010. Hunt and Hess grade and Fisher grade were recorded at admission. The Glasgow Coma Scale (GCS) score was calculated at admission and daily for seven postoperative days. Arterial blood was sampled at admission and for seven postoperative days to determine the PaO2/FIO2 ratio, C-reactive protein level, troponin I level, and NT-pro-BNP level. Urine was sampled at admission and daily for seven postoperative days to determine ACR and vanillylmandelic acid/creatinine ratio (VMACR). Neurological outcomes were assessed at hospital discharge by using the Glasgow Outcome Scale. Receiver operating characteristic curves were constructed for the predictive variables of unfavorable neurological outcomes, and the area under the curve (AUC) was determined. Multivariate logistic regression analyses were performed for the significant predictors of unfavorable neurological outcomes after SAH. Associations with NT-pro-BNP were evaluated by using the Spearman rank correlation test. RESULTS: Of the 61 patients, 24 had unfavorable outcomes. The prevalence rate of microalbuminuria was 85 % (52/61). The highest NT-pro-BNP levels were above the normal range in 57 of 61 patients (93 %). According to the AUC, the Hunt and Hess grade, GCS score, the highest ACR, and highest VMACR were significant predictors of neurological outcome. Multivariate logistic regression analyses showed that the highest ACR and Hunt and Hess grade are independent prognostic predictors of unfavorable neurological outcomes. The highest NT-pro-BNP significantly correlated with the highest troponin I, highest ACR, and VMACR on admission. CONCLUSIONS: The highest ACR is an independent prognostic predictor of unfavorable neurological outcomes after SAH. Moreover, plasma NT-pro-BNP elevation may be associated with the development of microalbuminuria.

13.
Eur J Pharm Sci ; 74: 77-85, 2015 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-25906910

RESUMO

Lipocalin-type prostaglandin D synthase (L-PGDS), a member of the lipocalin superfamily, possesses the function of forming complexes together with various small lipophilic molecules. In this study, we chose telmisartan as a model drug due to its pH dependent poor water solubility, and developed and characterized a novel solubilized formulation of telmisartan using a complex formulation with L-PGDS. The solid state of the complex formulation was prepared using a spray-drying process. The spray-dried formulation of telmisartan/L-PGDS powder showed a typical spray-dried particle without any change in the secondary and tertiary structures of L-PGDS. Furthermore, the complex formulation showed a high rate and level of drug release in pH 1.2, 5.0, and 6.8 solutions in comparison with the active pharmaceutical ingredient (API) and commercial product. To validate the potential for oral administration of the telmisartan/L-PGDS complex in vivo, the pharmacokinetic and pharmacodynamic profiles were assessed in spontaneous hypertensive rats. An animal study revealed that the complex formulation led to a significant improvement of AUC and Cmax as compared with API, and the prolonged pharmacologic effect on blood pressure reduction was comparable with the commercial product. These results, taken together, demonstrate that this novel approach is feasible for the solubilized solid oral formulation and it can be applied to poorly water-soluble drugs to enhance oral bioavailability.


Assuntos
Bloqueadores do Receptor Tipo 1 de Angiotensina II/administração & dosagem , Anti-Hipertensivos/administração & dosagem , Benzimidazóis/administração & dosagem , Benzoatos/administração & dosagem , Química Farmacêutica/métodos , Sistemas de Liberação de Medicamentos , Excipientes/química , Oxirredutases Intramoleculares/química , Lipocalinas/química , Administração Oral , Substituição de Aminoácidos , Bloqueadores do Receptor Tipo 1 de Angiotensina II/química , Bloqueadores do Receptor Tipo 1 de Angiotensina II/farmacocinética , Bloqueadores do Receptor Tipo 1 de Angiotensina II/uso terapêutico , Animais , Anti-Hipertensivos/química , Anti-Hipertensivos/farmacocinética , Anti-Hipertensivos/uso terapêutico , Benzimidazóis/química , Benzimidazóis/farmacocinética , Benzimidazóis/uso terapêutico , Benzoatos/química , Benzoatos/farmacocinética , Benzoatos/uso terapêutico , Digestão , Liberação Controlada de Fármacos , Estabilidade Enzimática , Excipientes/metabolismo , Estudos de Viabilidade , Humanos , Hipertensão/sangue , Hipertensão/tratamento farmacológico , Hipertensão/metabolismo , Oxirredutases Intramoleculares/genética , Oxirredutases Intramoleculares/metabolismo , Lipocalinas/genética , Lipocalinas/metabolismo , Masculino , Proteínas Mutantes/química , Proteínas Mutantes/metabolismo , Pós , Conformação Proteica , Distribuição Aleatória , Ratos Endogâmicos SHR , Proteínas Recombinantes/química , Proteínas Recombinantes/metabolismo , Solubilidade , Telmisartan
14.
PLoS One ; 6(6): e21238, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21731681

RESUMO

BACKGROUND: Despite its economic importance, we have a limited understanding of the molecular mechanisms underlying shell formation in pearl oysters, wherein the calcium carbonate crystals, nacre and prism, are formed in a highly controlled manner. We constructed comprehensive expressed gene profiles in the shell-forming tissues of the pearl oyster Pinctada fucata and identified novel shell formation-related genes candidates. PRINCIPAL FINDINGS: We employed the GS FLX 454 system and constructed transcriptome data sets from pallial mantle and pearl sac, which form the nacreous layer, and from the mantle edge, which forms the prismatic layer in P. fucata. We sequenced 260477 reads and obtained 29682 unique sequences. We also screened novel nacreous and prismatic gene candidates by a combined analysis of sequence and expression data sets, and identified various genes encoding lectin, protease, protease inhibitors, lysine-rich matrix protein, and secreting calcium-binding proteins. We also examined the expression of known nacreous and prismatic genes in our EST library and identified novel isoforms with tissue-specific expressions. CONCLUSIONS: We constructed EST data sets from the nacre- and prism-producing tissues in P. fucata and found 29682 unique sequences containing novel gene candidates for nacreous and prismatic layer formation. This is the first report of deep sequencing of ESTs in the shell-forming tissues of P. fucata and our data provide a powerful tool for a comprehensive understanding of the molecular mechanisms of molluscan biomineralization.


Assuntos
Estruturas Animais/metabolismo , Etiquetas de Sequências Expressas/metabolismo , Testes Genéticos , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Especificidade de Órgãos/genética , Pinctada/genética , Sequência de Aminoácidos , Animais , Sequência de Bases , Análise por Conglomerados , DNA Complementar/genética , Perfilação da Expressão Gênica , Regulação da Expressão Gênica , Biblioteca Gênica , Estudos de Associação Genética , Dados de Sequência Molecular , Homologia de Sequência do Ácido Nucleico
15.
Inorg Chem ; 50(13): 6353-60, 2011 Jul 04.
Artigo em Inglês | MEDLINE | ID: mdl-21648400

RESUMO

Complexation of three kinds of tris(imidazolyl)calix[6]arenes containing alternate p-substituents (Calix-tBu, R(1) = R(2) = tert-butyl; Calix-NH(2), R(1) = tert-butyl, R(2) = NH(2); Calix-NO(2), R(1) = tert-butyl, R(2) = NO(2)) with Zn(ClO(4))(2)(H(2)O)(6) in acetonitrile, methanol, and THF was investigated via isothermal titration calorimetry (ITC). For the coordination of these calixarene ligands to Zn(II) in acetonitrile, typical one-phase exothermic titration curves were obtained, indicating the formation of 1:1 ligand-Zn(II) complexes accompanied by large conformational changes of the ligands. In contrast, the complexation in methanol was endothermic and dominated by favorable entropy changes. The entropy gains were achieved by extensive desolvation from both Zn(II) and the ligands. ITC measurements suggest a 2:1 ligand-Zn(II) complex formation in THF in the presence of excess ligands (Calix-NH(2) and Calix-NO(2)). The 2:1 complexes were converted to 1:1 complexes upon further addition of Zn(ClO(4))(2)(H(2)O)(6). The results indicate the important role of a coordinating solvent (acetonitrile) for direct formation of the 1:1 complexes under the conditions of excess ligand. Complexation of a ditopic ligand (Calix-Tri) with three triazole moieties on the wider rim was also studied via ITC. The first coordination of the imidazole moieties to Zn(II) was an exothermic process. This was followed by the entropically favorable coordination of the triazole moieties to the divalent cation. We have also investigated exchange of the fourth ligand (H(2)O) of the Zn(II) complex of Calix-NH(2) with butylamine, heptylamine, acetonitrile, and acetamide in a noncompetitive solvent, THF. The ΔH(0) tended to decrease upon increasing the electron-pair-donating ability of the guest ligand, whereas it was also affected by an entropic term due to restricted rotation of the guest ligand inside the calixarene cavity.


Assuntos
Calixarenos/química , Imidazóis/química , Compostos Organometálicos/química , Fenóis/química , Zinco/química , Calorimetria , Íons/química , Ligantes , Estrutura Molecular , Compostos Organometálicos/síntese química , Solventes/química , Estereoisomerismo
16.
J Anesth ; 24(2): 264-7, 2010 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-20191293

RESUMO

We describe successful anesthetic management during living-donor liver transplantation in a 63-year-old man with previous coronary artery bypass grafting (CABG) that employed an in situ right gastroepiploic artery (RGEA). Anesthesia was maintained with 1.5% isoflurane in air/oxygen and fentanyl. A five-lead electrocardiogram, transesophageal echocardiogram, and pacing pulmonary artery catheter evaluated cardiac function. A pacing wire was inserted through the catheter to prepare for intraoperative severe bradyarrhythmia. Olprinone and nicorandil were continuously infused to prevent decrease in coronary arterial blood flow and the collapse of cardiac function. Avoiding disruption of circulation to coronary arteries through injury or spasm of the RGEA graft and preparing for cardiac insufficiency during liver transplantation of a patient with previous CABG using an in situ RGEA is critical.


Assuntos
Anestesia/métodos , Ponte de Artéria Coronária/métodos , Insuficiência Cardíaca/prevenção & controle , Transplante de Fígado , Antiarrítmicos/administração & dosagem , Cardiotônicos/administração & dosagem , Artéria Gastroepiploica , Humanos , Imidazóis/administração & dosagem , Masculino , Pessoa de Meia-Idade , Nicorandil/administração & dosagem , Piridonas/administração & dosagem
17.
J Vet Med Sci ; 72(3): 321-6, 2010 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-19996565

RESUMO

Tetrazolium salts such as XTT and MTT are widely used to produce formazan for cell proliferation and cytotoxicity assays through bioreductase activity. However, the XTT assay showed significant increase in MDBK cell viability when cells were treated with both 50 and 100 muM of the pro-oxidant, tert-butylhydroquinone (t-BHQ), although the crystal violet assay showed no cytotoxic effect with these concentrations, and the induction of lipid peroxidation was not observed. We investigated the mechanism of enhancement of XTT substrate reduction after treatment of MDBK cells with t-BHQ, leading to apparent increase in cell viability. t-BHQ caused an increase in absorbance at 340 nm in culture medium, suggesting that t-BHQ increases cellular production and release of NADH and/or NADPH. Although t-BHQ did not change the NADH concentration in cell culture medium, the addition of NADP(+)-dependent glutathione reductase decreased the XTT reduction to the control level, indicating cellular release of NADPH. t-BHQ also increased intracellular glucose-6-phosphate dehydrogenase activity, producing NADPH. Taken together, our findings indicate that t-BHQ treatment activates NADPH generating enzymes such as glucose-6-phosphate dehydrogenase followed by release of NADPH in the cell culture medium, resulting in direct XTT reduction by NADPH.


Assuntos
Glucosefosfato Desidrogenase/efeitos dos fármacos , Hidroquinonas/farmacologia , NADP/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Animais , Bovinos , Divisão Celular/efeitos dos fármacos , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Glucosefosfato Desidrogenase/metabolismo , Peroxidação de Lipídeos/efeitos dos fármacos , NAD/efeitos dos fármacos , NAD/metabolismo , NADP/efeitos dos fármacos
18.
J Anesth ; 23(4): 583-6, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-19921371

RESUMO

A 43-year-old woman with pulmonary fibrosis secondary to pulmonary alveolar proteinosis was scheduled to undergo lung transplantation. Before the lung transplantation, she had undergone multiple whole-lung lavage procedures on extracorporeal circulation (ECC), which had caused scarring of the right femoral subcutaneous tissues. Preoperative examination revealed a double inferior vena cava (IVC) with interiliac communication, and the left IVC ended at the left renal vein. Surgical exposure of the right femoral vessels was performed immediately after anesthetic induction for emergent vascular access to establish an ECC. Cardiopulmonary collapse did not occur and the ECC was not required until lung resection. The lung transplantation was completed uneventfully. Congenital IVC anomaly is rare, but may make cannulation through the femoral vein difficult. Scarring of the subcutaneous tissue could result in a difficult "percutaneous" approach to the vessels. Evaluation of the vascular anatomy related to the establishment of an ECC is important before lung transplantation.


Assuntos
Anestesia , Transplante de Pulmão , Proteinose Alveolar Pulmonar/cirurgia , Veia Cava Inferior/anormalidades , Adulto , Ecocardiografia Transesofagiana , Circulação Extracorpórea , Feminino , Humanos , Flebografia , Testes de Função Respiratória
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA