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1.
Nature ; 619(7969): 288-292, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37438595

RESUMO

The occurrence of superconductivity in proximity to various strongly correlated phases of matter has drawn extensive focus on their normal state properties, to develop an understanding of the state from which superconductivity emerges1-4. The recent finding of superconductivity in layered nickelates raises similar interests5-8. However, transport measurements of doped infinite-layer nickelate thin films have been hampered by materials limitations of these metastable compounds: in particular, a high density of extended defects9-11. Here, by moving to a substrate (LaAlO3)0.3(Sr2TaAlO6)0.7 that better stabilizes the growth and reduction conditions, we can synthesize the doping series of Nd1-xSrxNiO2 essentially free from extended defects. In their absence, the normal state resistivity shows a low-temperature upturn in the underdoped regime, linear behaviour near optimal doping and quadratic temperature dependence for overdoping. This is phenomenologically similar to the copper oxides2,12 despite key distinctions-namely, the absence of an insulating parent compound5,6,9,10, multiband electronic structure13,14 and a Mott-Hubbard orbital alignment rather than the charge-transfer insulator of the copper oxides15,16. We further observe an enhancement of superconductivity, both in terms of transition temperature and range of doping. These results indicate a convergence in the electronic properties of both superconducting families as the scale of disorder in the nickelates is reduced.

2.
Nat Mater ; 23(6): 775-781, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38182811

RESUMO

The discovery of superconductivity in infinite-layer nickelates established another category of unconventional superconductors that shares structural and electronic similarities with cuprates. However, key issues of the superconducting pairing symmetry, gap amplitude and superconducting fluctuations are yet to be addressed. Here we utilize static and ultrafast terahertz spectroscopy to address these. We demonstrate that the equilibrium terahertz conductivity and non-equilibrium terahertz responses of an optimally Sr-doped nickelate film (superconducting transition temperature of Tc = 17 K) are in line with the electrodynamics of d-wave superconductivity in the dirty limit. The gap-to-Tc ratio (2Δ/kBTc) is found to be 3.4, indicating that the superconductivity falls in the weak coupling regime. In addition, we observed substantial superconducting fluctuations near Tc that do not extend into the deep normal state as the optimally hole-doped cuprates do. Our results support a d-wave system that closely resembles the electron-doped cuprates.

3.
Small ; 16(45): e2003986, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-33078539

RESUMO

An effective strategy is developed to create peptide-based hierarchical nanostructures through the meniscus-driven self-assembly in a large area and fabricate antiferroelectric devices based on these nanostructures for the first time. The diphenylalanine hierarchical nanostructures (FF-HNs) are self-assembled by vertically pulling a substrate from a diphenylalanine (FF) solution dissolved in a miscible solvent under precisely controlled conditions. Owing to the unique structural properties of FF nanostructures, including high crystallinity and α-helix structures, FF-HNs possess a net electrical dipole moment, which can be switched in an external electric field. The mass production of antiferroelectric devices based on FF-HNs can be successfully achieved by means of this biomimetic assembly technique. The devices show an evident antiferroelectric to ferroelectric transition under dark conditions, while the ferroelectricity is found to be tunable by light. Notably, it is discovered that the modulation of antiferroelectric behaviors of FF-HNs under glutaraldehyde exposure is due to the FF molecules that are transformed into cyclophenylalanine by glutaraldehyde. This work provides a stepping stone toward the mass production of self-assembled hierarchical nanostructures based on biomolecules as well as the mass fabrication of electronic devices based on biomolecular nanostructures for practical applications.


Assuntos
Nanoestruturas , Eletricidade , Peptídeos , Solventes
4.
Br J Anaesth ; 125(6): 976-985, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-32861508

RESUMO

BACKGROUND: We aimed to characterise the population pharmacokinetics of fentanyl in adults and to determine the minimum effective concentration (MEC) and minimum effective analgesic concentration (MEAC) of i.v. fentanyl in patients after major abdominal open surgery. METHODS: In the pharmacokinetic study, subjects received an intravenous bolus of fentanyl 100 µg during operation, and arterial blood was sampled at pre-set intervals. In addition, data from previously published fentanyl pharmacokinetic studies were incorporated to build a pharmacokinetic model. In the MEAC study, subjects were asked to rate their pain every 10 min using a VAS (0=no pain, 10=most severe pain) in the PACU. The first blood sample was obtained when wound pain was rated as ≥3 at rest or ≥5 during compression. Then, fentanyl 50 µg was administered every 10 min until the pain intensity had decreased to <3 at rest and <5 during compression, at which point the second blood was sampled and the first MEAC of fentanyl was measured. The same procedure was repeated to obtain a third sample (MEC) and a fourth sample (second MEAC). RESULTS: In the population pharmacokinetic study (n=95), the plasma concentration of fentanyl over time was well-described by the three-compartment mammillary model using an allometric expression. The V1, V2, V3, Cl, Q1, and Q2 of a 70 kg subject were 10.1, 26.5, 206 L, 0.704, 2.38, and 1.49 L min-1, respectively. In the MEAC study (n=30), the median (inter-quartile range) MEC and MEAC were 0.72 (0.58-1.05) ng ml-1, and 0.99 (0.76-1.28) ng ml-1, respectively. CONCLUSION: These results provide a scientific basis for the use of fentanyl for acute postoperative pain management in surgical patients. CLINICAL TRIAL REGISTRATION: KCT0003273 (http://cris.nih.go.kr).


Assuntos
Abdome/cirurgia , Analgésicos Opioides/farmacocinética , Analgésicos Opioides/uso terapêutico , Fentanila/farmacocinética , Fentanila/uso terapêutico , Dor Pós-Operatória/tratamento farmacológico , Adulto , Idoso , Idoso de 80 Anos ou mais , Conjuntos de Dados como Assunto , Relação Dose-Resposta a Droga , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Adulto Jovem
5.
J Clin Monit Comput ; 34(5): 1087-1093, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31628569

RESUMO

We evaluated the performance of the Surgical Plethysmographic Index (SPI) and the Analgesia Nociception Index (ANI) as surrogate pain measures and determined their respective cut-off values for detecting pain in conscious postoperative patients. In total, 192 patients after elective surgery were enrolled. Baseline SPI and ANI data were acquired for 10 min in the operating room prior to surgery when the patients rated their pain as 0 on the numerical rating scale (NRS). Upon arrival in the post-anaesthesia care unit (PACU) after surgery, SPI and ANI data were recorded for 10 min. The means of the recorded data at OR and PACU were defined as the values representing baseline and postoperative pain, respectively. SPI and ANI data obtained from 189 patients were analysed, who were anesthetized with propofol (n = 149) or sevoflurane (n = 40). Remifentanil was continuously infused intraoperatively in all patients. The values of SPI and ANI were significantly different in conscious patients without (NRS = 0) and with pain (NRS > 0). The areas under the receiver operating curves for SPI and ANI were 0.73 (P < 0.0001) and 0.67 (P < 0.0001), respectively. The cut-off values for SPI and ANI in predicting postoperative pain were 44 (sensitivity: 84%, specificity: 53%) and 63 (sensitivity: 52%, specificity: 82%), respectively, which are different from those suggested by their respective manufacturers for use in intraoperative state under general anaesthesia. The cut-off values of SPI and ANI for detecting pain were similar regardless of the type of anesthesia.


Assuntos
Analgesia , Nociceptividade , Anestesia Geral , Humanos , Dor Pós-Operatória/diagnóstico , Estudos Prospectivos
6.
Acta Pharmacol Sin ; 40(5): 710-716, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30327545

RESUMO

In order to maintain stable blood pressure and heart rate during surgery, anesthesiologists need to administer the appropriate amount of fluid with appropriate fluid type to the patient, then quantifying how fluid is distributed and eliminated from the body is useful for establishing a fluid administration strategy. In this study we characterized the volume kinetics of Ringer's lactate solution in patients undergoing open gastrectomy. When propofol and remifentanil reached a pseudosteady state at the target concentration and blood pressure was stabilized following surgical stimulation, enrolled patients were administered 1000 mL of Ringer's lactate solution for 20 min, followed by continuous infusion at a rate of 6 mL/kg/h until the time of the last blood collection for volume kinetic analysis. Arterial blood samples were collected to measure the hemoglobin concentration at different time points. The change in hemoglobin-derived plasma dilution induced by the administration of Ringer's lactate solution was evaluated by nonlinear mixed effects modeling. Three hundred and twenty-three plasma dilution data points from 27 patients were used to determine the pharmacokinetic characteristics of Ringer's lactate solution. A two-volume model best described the pharmacokinetics of Ringer's lactate solution. The mean arterial pressure (MAP) and body weight (WT) were significant covariates for the elimination clearance (kr) and central volume of distribution at baseline (Vc0), respectively. The parameter estimates were as follows: kr (mL/min) = 124 + (MAP/70)14.2, Vc0 (mL) = 0.95 + 3440 × (WT/63), Vt0 (mL) = 2730, and kt (mL/min) = 181. A higher MAP was associated with a greater elimination clearance and, consequently, less water accumulation in the interstitium. As body weight increases, volume expansion in the blood vessels increases.


Assuntos
Gastrectomia/estatística & dados numéricos , Hemoglobinas/análise , Lactato de Ringer/farmacocinética , Adulto , Idoso , Idoso de 80 Anos ou mais , Pressão Arterial , Peso Corporal , Feminino , Frequência Cardíaca , Humanos , Infusões Intravenosas , Cinética , Masculino , Pessoa de Meia-Idade , Lactato de Ringer/administração & dosagem
7.
Acta Anaesthesiol Scand ; 63(4): 448-454, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30690713

RESUMO

BACKGROUND: In a previous study, the modified Marsh and Schnider models respectively showed negatively- and positively-biased predictions in underweight patients. To overcome this drawback, we developed a new pharmacokinetic propofol model-the Choi model-for use in underweight patients. In the present study, we evaluated the predictive performance of the Choi model. METHODS: Twenty underweight patients undergoing elective surgery received propofol via TCI using the Choi model. The target effect-site concentrations (Ces) of propofol were 2.5, 3, 3.5, 4, 4.5, and 2 µg/mL. Arterial blood samples were obtained at least 10 minutes after achieving pseudo-steady-state. Predicted propofol concentrations with the modified Marsh, Schnider, and Eleveld pharmacokinetic models were obtained by simulation (Asan pump, version 2.1.3; Bionet Co. Ltd., Seoul, Korea). The predictive performance of each model was assessed by calculation of four parameters: inaccuracy, divergence, bias, and wobble. RESULTS: A total of 119 plasma samples were used to determine the predictive performance of the Choi model. Our evaluation showed that the pooled median (95% CI) bias and inaccuracy were 4.0 (-4.2 to 12.2) and 23.9 (17.6-30.3), respectively. The pooled biases and inaccuracies of the modified Marsh, Schnider, and Eleveld models were clinically acceptable. However, the modified Marsh and Eleveld models consistently produced negatively biased predictions in underweight patients. In particular, the Schnider model showed greater inaccuracy at a target Ce ≥ 3 µg/mL. CONCLUSION: The new propofol pharmacokinetic model (the Choi model) developed for underweight patient showed adequate performance for clinical use.


Assuntos
Anestesia Intravenosa/métodos , Anestésicos Intravenosos/administração & dosagem , Anestésicos Intravenosos/farmacocinética , Propofol/administração & dosagem , Propofol/farmacocinética , Magreza/metabolismo , Adulto , Idoso , Algoritmos , Anestésicos Intravenosos/sangue , Procedimentos Cirúrgicos Eletivos , Feminino , Humanos , Infusões Intravenosas , Masculino , Pessoa de Meia-Idade , Modelos Biológicos , Valor Preditivo dos Testes , Propofol/sangue , Reprodutibilidade dos Testes , Magreza/complicações , Adulto Jovem
8.
Eur J Anaesthesiol ; 36(11): 863-870, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31503037

RESUMO

BACKGROUND: Evidence on whether the use of deep neuromuscular block (NMB) influences postoperative pain after laparoscopic surgery is limited, and existing studies have shown conflicting results. We studied the effect of the depth of NMB during laparoscopic gastrectomy on postoperative pain. OBJECTIVE: The aim of this study was to evaluate the effect of depth of NMB during laparoscopic gastrectomy on postoperative pain by allocating patients randomly to either deep or moderate NMB with a standard-pressure pneumoperitoneum. DESIGN: A randomised, controlled, double-blind study. SETTING: A university-affiliated hospital. PARTICIPANTS: One hundred patients. INTERVENTIONS: Patients were allocated randomly to receive either deep (posttetanic count 1 to 2) or moderate (train-of-four count 1 to 2) levels of NMB. Following surgery, the patients were asked to rate their pain every 10 min using a visual analogue scale (VAS) (0 = no pain, 10 = most severe pain) in the postanaesthesia care unit (PACU). Patients received intravenous oxycodone, 2 mg every 10 min, until the pain intensity (VAS) had decreased to less than 3 at rest and less than 5 on wound compression, at which point the minimum effective analgesia dose (MEAD) of oxycodone was determined. MAIN OUTCOME MEASURES: The primary endpoint was the MEAD of oxycodone. Secondary endpoints included area under the curve of VAS for wound pain, VAS scores for wound and shoulder pain at 6 and 24 h after the end of surgery, rescue analgesics, a five-point surgical rating scale, Rhodes index of nausea vomiting retching at 6 and 24 h after the end of surgery and duration of pneumoperitoneum. RESULTS: The median value for the MEAD of oxycodone was 8 mg in both groups. Area under the curves of VAS over time were similar in both groups. Variables associated with postoperative pain including mean VAS at PACU and frequency of rescue analgesics in the ward did not differ significantly between the two groups. The duration of pneumoperitoneum was a significant variable in determining the MEAD of oxycodone (linear regression, R = 0.07, P = 0.008). The number of patients who reached the acceptable surgical score was not significantly different between the two groups. However, the moderate NMB group did have a significantly higher proportion of cases that required additional muscle relaxants (P < 0.001). CONCLUSION: Deep, compared with moderate, NMB did not significantly reduce the MEAD of oxycodone administered in the PACU. The duration of pneumoperitoneum was positively correlated with the MEAD. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT03266419.


Assuntos
Gastrectomia/métodos , Laparoscopia/métodos , Bloqueio Neuromuscular/métodos , Dor Pós-Operatória/prevenção & controle , Analgésicos Opioides/administração & dosagem , Método Duplo-Cego , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Oxicodona/administração & dosagem , Medição da Dor , Pneumoperitônio Artificial/métodos , Dor de Ombro/epidemiologia , Fatores de Tempo , Resultado do Tratamento
9.
Lancet ; 390(10091): 267-275, 2017 07 15.
Artigo em Inglês | MEDLINE | ID: mdl-28576285

RESUMO

BACKGROUND: Delirium is a common and serious postoperative complication. Subanaesthetic ketamine is often administered intraoperatively for postoperative analgesia, and some evidence suggests that ketamine prevents delirium. The primary purpose of this trial was to assess the effectiveness of ketamine for prevention of postoperative delirium in older adults. METHODS: The Prevention of Delirium and Complications Associated with Surgical Treatments [PODCAST] study is a multicentre, international randomised trial that enrolled adults older than 60 years undergoing major cardiac and non-cardiac surgery under general anaesthesia. Using a computer-generated randomisation sequence we randomly assigned patients to one of three groups in blocks of 15 to receive placebo (normal saline), low-dose ketamine (0·5 mg/kg), or high dose ketamine (1·0 mg/kg) after induction of anaesthesia, before surgical incision. Participants, clinicians, and investigators were blinded to group assignment. Delirium was assessed twice daily in the first 3 postoperative days using the Confusion Assessment Method. We did analyses by intention-to-treat and assessed adverse events. This trial is registered with clinicaltrials.gov, number NCT01690988. FINDINGS: Between Feb 6, 2014, and June 26, 2016, 1360 patients were assessed, and 672 were randomly assigned, with 222 in the placebo group, 227 in the 0·5 mg/kg ketamine group, and 223 in the 1·0 mg/kg ketamine group. There was no difference in delirium incidence between patients in the combined ketamine groups and the placebo group (19·45% vs 19·82%, respectively; absolute difference 0·36%, 95% CI -6·07 to 7·38, p=0·92). There were more postoperative hallucinations (p=0·01) and nightmares (p=0·03) with increasing ketamine doses compared with placebo. Adverse events (cardiovascular, renal, infectious, gastrointestinal, and bleeding), whether viewed individually (p value for each >0·40) or collectively (36·9% in placebo, 39·6% in 0·5 mg/kg ketamine, and 40·8% in 1·0 mg/kg ketamine groups, p=0·69), did not differ significantly across groups. INTERPRETATION: A single subanaesthetic dose of ketamine did not decrease delirium in older adults after major surgery, and might cause harm by inducing negative experiences. FUNDING: National Institutes of Health and Cancer Center Support.


Assuntos
Analgésicos/administração & dosagem , Fármacos do Sistema Nervoso Central/administração & dosagem , Delírio/prevenção & controle , Ketamina/administração & dosagem , Dor Pós-Operatória/prevenção & controle , Idoso , Analgésicos/efeitos adversos , Fármacos do Sistema Nervoso Central/efeitos adversos , Método Duplo-Cego , Esquema de Medicação , Feminino , Humanos , Cuidados Intraoperatórios/métodos , Ketamina/efeitos adversos , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias/prevenção & controle , Resultado do Tratamento
10.
Br J Clin Pharmacol ; 83(2): 314-325, 2017 02.
Artigo em Inglês | MEDLINE | ID: mdl-27558774

RESUMO

AIMS: This prospective study aimed to characterize the population pharmacokinetics of intravenous oxycodone and to determine the minimum effective concentration (MEC) and minimum effective analgesic concentration (MEAC) of oxycodone for major open intra-abdominal surgery. METHODS: In the pharmacokinetic study, patients were administered intravenous oxycodone (0.1 mg kg-1 ), and arterial blood was sampled at pre-set intervals. In the analgesic-potency study, patients were administered intravenous oxycodone (0.1 mg kg-1 ) 30 min before the end of the surgery, were placed in the postoperative anaesthesia care unit (PACU), and were asked to rate their pain every 10 min using a visual analogue scale (0 = no pain, 10 = most severe pain). On the first occasion that wound pain at rest and during compression was rated as ≥3 or ≥5, respectively, the first blood sample was obtained to determine the MEC. A second blood sample was obtained after titration with 2 mg of oxycodone to yield wound pain <3 at rest and <5 during wound compression, and MEAC was determined. MEC and MEAC were determined again in each patient. RESULTS: In the population pharmacokinetic study (n = 54), oxycodone plasma concentration over time was well described by a three-compartment mammillary model. Lean body mass and age were significant covariates for the volume of distribution and metabolic clearance of the pharmacokinetic model of oxycodone, respectively. The analgesic-potency study (n = 50) showed that the median (95% CI) MEC and MEAC were 31.5 (19.2-42.8) and 74.1 (29.2-128.3) ng ml-1 (first measurements) and 63.4 (15.6-120.1) and 76.1 (32.9-132.7) ng ml-1 (second measurements), respectively. CONCLUSIONS: In major intra-abdominal open surgery, the MEAC and analgesic potency of oxycodone were 75 ng ml-1 and 60 ng ml-1 , respectively.


Assuntos
Analgésicos Opioides/administração & dosagem , Modelos Biológicos , Oxicodona/administração & dosagem , Dor Pós-Operatória/tratamento farmacológico , Abdome/cirurgia , Administração Intravenosa , Idoso , Analgésicos Opioides/farmacocinética , Analgésicos Opioides/farmacologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Oxicodona/farmacocinética , Oxicodona/farmacologia , Medição da Dor , Estudos Prospectivos
11.
Clin Exp Pharmacol Physiol ; 44(1): 30-40, 2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-27696490

RESUMO

This study describes the pharmacodynamic interaction between propofol and remifentanil. Sixty patients who were scheduled for elective surgery under general anaesthesia (30 males/30 females) were enrolled. Patients were randomly allocated to receive one of 15 combinations of drug levels. Baseline electroencephalograms (EEGs) were recorded for 5 minutes prior to administering the drugs. Patients received a target-controlled infusion at one of four predefined doses of propofol (high, 3 µg/mL; medium, 1.5 µg/mL; low, 0.5 µg/mL; or no drug) and of remifentanil (high, 6 or 8 ng/mL; medium, 4 ng/mL; low, 2 ng/mL; or no drug). The occurrence of muscle rigidity, apnoea, and loss of consciousness (LOC) was monitored, and EEGs were recorded during the drug administration phase. Electroencephalographic approximate entropy (ApEn) and temporal linear mode complexity (TLMC) parameters at baseline and under steady state conditions were calculated off-line. Response surfaces were developed to map the interaction between propofol and remifentanil to the probability of occurrence for quantal responses (muscle rigidity, apnoea, LOC) and ApEn and TLMC measurements. Model parameters were estimated using non-linear mixed effects modelling. The response surface revealed infra-additive and synergistic effects for muscle rigidity and apnoea, respectively. The effects of the combined drugs on LOC and EEG parameters (eg, ApEn and TLMC) were additive. The C50 estimates of remifentanil (ng/mL) and propofol (µg/mL) were 9.11 and 130 000 for muscle rigidity, 8.99 and 6.26 for apnoea, 13.9 and 3.04 for LOC, 23.4 and 10.4 for ApEn, and 14.8 and 6.51 for TLMC, respectively. The probability of occurrence for muscle rigidity declined when propofol was combined with remifentanil.


Assuntos
Anestesia Intravenosa , Piperidinas/administração & dosagem , Piperidinas/metabolismo , Propofol/administração & dosagem , Propofol/metabolismo , Anestesia Intravenosa/tendências , Anestésicos Intravenosos , Relação Dose-Resposta a Droga , Interações Medicamentosas/fisiologia , Quimioterapia Combinada , Procedimentos Cirúrgicos Eletivos/tendências , Eletroencefalografia/efeitos dos fármacos , Eletroencefalografia/métodos , Feminino , Humanos , Masculino , Modelos Biológicos , Rigidez Muscular/induzido quimicamente , Rigidez Muscular/metabolismo , Piperidinas/efeitos adversos , Propofol/efeitos adversos , Remifentanil
12.
Br J Clin Pharmacol ; 82(3): 762-72, 2016 09.
Artigo em Inglês | MEDLINE | ID: mdl-27195435

RESUMO

AIMS: This study characterized the pharmacokinetics of ramosetron and compared prophylactic anti-emetic efficacy with that of ondansetron in a large population. METHODS: Fifty-eight patients consented to the pharmacokinetic analysis and were assigned randomly to receive 0.3, 0.45 or 0.6 mg ramosetron after induction of anaesthesia. Blood samples were acquired at preset intervals. Non-compartmental and population pharmacokinetic analyses were performed. In total, 1102 patients consented to the evaluation of prophylactic anti-emetic efficacy and were allocated randomly to receive 0.3 mg ramosetron or 4 mg ondansetron at the end of surgery. An additional 16 mg ondansetron were mixed in the intravenous patient-controlled analgesia pump of the ondansetron group. Post-operative nausea and vomiting (PONV) were evaluated 6, 24 and 48 h post-operatively using the Rhodes index of nausea, vomiting and retching (RINVR). Administration of rescue anti-emetics and adverse events were evaluated. RESULTS: The pharmacokinetic parameter estimates were V1 (l) = 5.12, V2 (l) = 108, CL (l⋅min(-1) ) = 0.08 + (59⋅age(-1) ) × 0.09, Q (l⋅min(-1) ) = 1.42. The incidences of PONV in the ramosetron and ondansetron groups were 77 (13.9%) and 113 (20.6%) and 44 (7.9%) and 66 (12.0%) at 24 and 48 h post-operatively, respectively (P = 0.004, 0.030). RINVR was significantly lower in the ramosetron than the ondansetron group 24 and 48 h post-operatively (P = 0.003, 0.025). Use of rescue anti-emetics and incidence of adverse events were comparable. CONCLUSIONS: A two compartment mammillary model was used to describe ramosetron pharmacokinetics. Prophylactic anti-emetic efficacy of ramosetron was significantly better 24 and 48 h post-operatively than that of ondansetron, particularly when the Apfel score was ≥ 3.


Assuntos
Benzimidazóis/farmacocinética , Benzimidazóis/uso terapêutico , Náusea e Vômito Pós-Operatórios/prevenção & controle , Antieméticos/efeitos adversos , Antieméticos/sangue , Antieméticos/farmacocinética , Antieméticos/uso terapêutico , Benzimidazóis/efeitos adversos , Benzimidazóis/sangue , Método Duplo-Cego , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Modelos Biológicos , Ondansetron/efeitos adversos , Ondansetron/sangue , Ondansetron/farmacocinética , Ondansetron/uso terapêutico , Náusea e Vômito Pós-Operatórios/sangue
13.
FASEB J ; 28(3): 1248-67, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24308972

RESUMO

The bone morphogenetic protein (BMP) signaling pathways have important roles in embryonic development and cellular homeostasis, with aberrant BMP signaling resulting in a broad spectrum of human disease. We report that BMPs unexpectedly signal through the canonical transforming growth factor ß (TGF-ß)-responsive Smad2 and Smad3. BMP-induced Smad2/3 signaling occurs preferentially in embryonic cells and transformed cells. BMPs signal to Smad2/3 by stimulating complex formation between the BMP-binding TGF-ß superfamily receptors, activin receptor-like kinase (ALK)3/6, and the Smad2/3 phosphorylating receptors ALK5/7. BMP signaling through Smad2 mediates, in part, dorsoventral axis patterning in zebrafish embryos, whereas BMP signaling through Smad3 facilitates cancer cell invasion. Consistent with increased BMP-mediated Smad2/3 signaling during cancer progression, Smad1/5 and Smad 2/3 signaling converge in human cancer specimens. Thus, the signaling mechanisms used by BMPs and TGF-ß superfamily receptors are broader than previously appreciated.


Assuntos
Proteínas Morfogenéticas Ósseas/metabolismo , Transdução de Sinais , Proteína Smad2/metabolismo , Proteína Smad3/metabolismo , Animais , Humanos , Fosforilação
14.
Can J Anaesth ; 62(10): 1063-70, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25894912

RESUMO

PURPOSE: Positional change can displace an endotracheal tube (ETT) and change the ETT cuff pressure in a tracheally intubated patient. Endotracheal tubes with different cuff shapes may lead to different cuff pressures after positional change. We hypothesized that the intracuff pressure in the TaperGuard™ ETT with a tapered-shaped cuff would be higher than that in the conventional ETT with a cylindrical-shaped cuff after a change from the supine to the lateral flank position. METHODS: Fifty-eight patients scheduled for open urological procedures in the lateral flank position were randomly allocated to receive either a TaperGuard ETT (group T) or conventional ETT (group C). The ETT cuff pressure was initially set at 20 cm H2O in the supine position and was measured after the change to the lateral flank position. The distance from the ETT tip to the carina was measured in both the supine and the lateral flank positions. RESULTS: Two patients, one from each group, were excluded from the data analysis. The mean (SD) ETT cuff pressure was significantly higher in group T (n = 28) than in group C (n = 28) after the change in position [31 (7) cm H2O vs 25 (4) cm H2O, respectively; mean difference, 6 cm; 95% confidence intervals [CI], 3 to 9; P < 0.001]. The mean (SD) proximal migration of the ETT tip was comparable between the two groups [8 (18) mm vs 4 (14) mm, respectively; P = 0.367]. CONCLUSIONS: After the change from the supine to the lateral flank position, the ETT cuff pressure was significantly higher in the TaperGuard ETT than in the conventional ETT, although the extent of cephalad displacement of the ETT was comparable between the two groups. This trial was registered at Clinicaltrials.gov: NCT02165319.


Assuntos
Intubação Intratraqueal/métodos , Posicionamento do Paciente , Procedimentos Cirúrgicos Urológicos/métodos , Adulto , Idoso , Feminino , Humanos , Intubação Intratraqueal/instrumentação , Masculino , Pessoa de Meia-Idade , Pressão , Método Simples-Cego
15.
Eur J Anaesthesiol ; 32(8): 549-54, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25564781

RESUMO

BACKGROUND: Excessive tracheal cuff pressure reduces tracheal mucosal blood flow and increases tracheal morbidity. Inserting a transoesophageal echocardiography (TOE) probe has been shown to increase tracheal cuff pressure. OBJECTIVE: To evaluate the effect of inserting a TOE probe on tracheal cuff pressure and compare the effect in patients who received a single-lumen endotracheal tube (SLT) with those who received a double-lumen endotracheal tube (DLT). DESIGN: A prospective, observational study. SETTING: Single-centre trial, study period from October 2013 to January 2014. PATIENTS: Forty-four adult patients scheduled for elective cardiothoracic surgery requiring intraoperative TOE monitoring. INTERVENTIONS: After tracheal intubation with a SLT (n = 22) or DLT (n = 22), the tracheal cuff was inflated to 18 mmHg (25 cmH2O) with air. Tracheal cuff pressure was monitored continuously for 5 min after inserting the TOE probe. MAIN OUTCOME MEASURES: The primary endpoint was steady-state tracheal cuff pressure after insertion of the TOE probe. RESULTS: Median (interquartile range, IQR) tracheal cuff pressure stabilised at 3 (2 to 3) min in the SLT group and at 2 (1 to 3) min in the DLT group. Steady-state cuff pressure was significantly higher in the DLT group than that in the SLT group [36.7 (31.3 to 44.1) vs. 31.3 (29.6 to 35.7) cmH2O; (P = 0.03)]. Steady-state cuff pressure more than 40 cmH2O was observed in two patients (18.2%) in the SLT group and nine patients (40.9%) in the DLT group (P = 0.02). CONCLUSION: Insertion of a TOE probe increased tracheal cuff pressure in both the SLT and DLT groups. The increase in cuff pressure was greater in patients who received a DLT. Frequent measurement and adjustment of cuff pressure should be emphasised particularly when TOE is used in patients receiving a DLT. TRIAL REGISTRATION: Clinicaltrials.gov identifier: NCT02034643.


Assuntos
Ecocardiografia Transesofagiana/instrumentação , Intubação Intratraqueal/instrumentação , Monitorização Intraoperatória/instrumentação , Pressão , Traqueia/fisiologia , Idoso , Ecocardiografia Transesofagiana/efeitos adversos , Ecocardiografia Transesofagiana/métodos , Feminino , Humanos , Intubação Intratraqueal/efeitos adversos , Intubação Intratraqueal/métodos , Masculino , Pessoa de Meia-Idade , Monitorização Intraoperatória/métodos , Pressão/efeitos adversos , Estudos Prospectivos
16.
Eur J Anaesthesiol ; 32(9): 596-601, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25485879

RESUMO

BACKGROUND: Catheter-related bladder discomfort (CRBD) due to an indwelling urinary catheter causes postoperative distress. Dexmedetomidine is used as an anaesthetic adjuvant during general anaesthesia and has an antimuscarinic effect, which may be beneficial for the prevention and treatment of CRBD. OBJECTIVE: To determine the effect of intraoperative dexmedetomidine administration on the incidence of CRBD. DESIGN: A double-blind, placebo-controlled, randomised study. SETTING: A tertiary care teaching hospital. PATIENTS: One-hundred and nine patients undergoing transurethral bladder tumour excision (TURB). INTERVENTIONS: Patients were randomly allocated to two groups: control group (n = 55) received placebo and dexmedetomidine group (n = 54) received intraoperative dexmedetomidine (1 µg kg(-1) loading dose followed by 0.5 µg kg(-1) h(-1) continuous infusion). MAIN OUTCOME MEASURES: The incidence and severity (mild, moderate, severe) of CRBD assessed at 0, 1, 6 and 24 h postoperatively. RESULTS: The incidence of CRBD was significantly higher in the control group at 0 (78 vs. 50%; P = 0.004), 1 (86 vs. 57%; P = 0.002) and 6 h (82 vs. 63%; P = 0.047) postoperatively. The incidence of moderate to severe CRBD was higher in the control group at 0 (38 vs. 11%; P = 0.002) and 1 h (29 vs. 7%; P = 0.006) postoperatively. The number of patients having CRBD treated with tramadol was higher in the control group (24 vs. 12; P = 0.006). The mean end-tidal desflurane concentration during the surgery was higher in the control group (4.5 vs. 3.9%; P = 0.04). The postoperative pain score (numerical rating scale: 0 to 10) was higher in the control group at 0 (4.6 vs. 2.7; P = 0.002), and 1 h (3.8 vs. 2.7; P = 0.041). The number of patients treated with opioids was higher in the control group (21 vs. 8; P = 0.011). CONCLUSION: Intraoperative dexmedetomidine administration decreased the incidence and severity of early postoperative CRBD as well as intraoperative desflurane and postoperative opioid requirements in patients undergoing TURB. TRIAL REGISTRATION IDENTIFIER: NCT01991223 (www.clinicaltrials.gov).


Assuntos
Dexmedetomidina/administração & dosagem , Cuidados Intraoperatórios/métodos , Dor Pós-Operatória/prevenção & controle , Neoplasias da Bexiga Urinária/cirurgia , Bexiga Urinária/cirurgia , Cateteres Urinários/efeitos adversos , Idoso , Analgésicos não Narcóticos/administração & dosagem , Método Duplo-Cego , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Medição da Dor/efeitos dos fármacos , Medição da Dor/métodos , Dor Pós-Operatória/diagnóstico , Dor Pós-Operatória/etiologia , Resultado do Tratamento , Bexiga Urinária/patologia , Neoplasias da Bexiga Urinária/diagnóstico
17.
BMC Cancer ; 14: 928, 2014 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-25491510

RESUMO

BACKGROUND: Amyloid-ß precursor protein (APP) is a highly conserved single transmembrane protein that has been linked to Alzheimer disease. Recently, the increased expression of APP in multiple types of cancers has been reported where it has significant correlation with the cancer cell proliferation. However, the function of APP in the pathogenesis of breast cancer has not previously been determined. In this study, we studied the pathological role of APP in breast cancer and revealed its potential mechanism. METHODS: The expression level of APP in multiple breast cancer cell lines was measured by Western blot analysis and the breast cancer tissue microarray was utilized to analyze the expression pattern of APP in human patient specimens. To interrogate the functional role of APP in cell growth and apoptosis, the effect of APP knockdown in MDA-MB-231 cells were analyzed. Specifically, multiple signal transduction pathways and functional alterations linked to cell survival and motility were examined in in vivo animal model as well as in vitro cell culture with the manipulation of APP expression. RESULTS: We found that the expression of APP is increased in mouse and human breast cancer cell lines, especially in the cell line possessing higher metastatic potential. Moreover, the analysis of human breast cancer tissues revealed a significant correlation between the level of APP and tumor development. Knockdown of APP (APP-kd) in breast cancer cells caused the retardation of cell growth in vitro and in vivo, with both the induction of p27(kip1) and caspase-3-mediated apoptosis. APP-kd cells also had higher sensitivity to treatment of chemotherapeutic agents, TRAIL and 5-FU. Such anti-tumorigenic effects shown in the APP-kd cells partially came from reduced pro-survival AKT activation in response to IGF-1, leading to activation of key signaling regulators for cell growth, survival, and pro-apoptotic events such as GSK3-ß and FOXO1. Notably, knock-down of APP in metastatic breast cancer cells limited cell migration and invasion ability upon stimulation of IGF-1. CONCLUSION: The present data strongly suggest that the increase of APP expression is causally linked to tumorigenicity as well as invasion of aggressive breast cancer and, therefore, the targeting of APP may be an effective therapy for breast cancer.


Assuntos
Precursor de Proteína beta-Amiloide/metabolismo , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Movimento Celular , Precursor de Proteína beta-Amiloide/genética , Animais , Apoptose/genética , Neoplasias da Mama/genética , Linhagem Celular Tumoral , Movimento Celular/genética , Proliferação de Células , Sobrevivência Celular/genética , Inibidor de Quinase Dependente de Ciclina p27/genética , Inibidor de Quinase Dependente de Ciclina p27/metabolismo , Modelos Animais de Doenças , Feminino , Expressão Gênica , Técnicas de Silenciamento de Genes , Humanos , Fator de Crescimento Insulin-Like I/metabolismo , Fator de Crescimento Insulin-Like I/farmacologia , Camundongos , Estadiamento de Neoplasias , Proteínas Proto-Oncogênicas c-akt/metabolismo , Ensaios Antitumorais Modelo de Xenoenxerto
18.
Nat Commun ; 15(1): 4743, 2024 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-38834672

RESUMO

Recent theoretical studies have suggested that transition metal perovskite oxide membranes can enable surface phonon polaritons in the infrared range with low loss and much stronger subwavelength confinement than bulk crystals. Such modes, however, have not been experimentally observed so far. Here, using a combination of far-field Fourier-transform infrared (FTIR) spectroscopy and near-field synchrotron infrared nanospectroscopy (SINS) imaging, we study the phonon polaritons in a 100 nm thick freestanding crystalline membrane of SrTiO3 transferred on metallic and dielectric substrates. We observe a symmetric-antisymmetric mode splitting giving rise to epsilon-near-zero and Berreman modes as well as highly confined (by a factor of 10) propagating phonon polaritons, both of which result from the deep-subwavelength thickness of the membranes. Theoretical modeling based on the analytical finite-dipole model and numerical finite-difference methods fully corroborate the experimental results. Our work reveals the potential of oxide membranes as a promising platform for infrared photonics and polaritonics.

19.
Immune Netw ; 23(2): e17, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37179751

RESUMO

Latent membrane protein 2A (LMP2A), a latent Ag commonly expressed in Epstein-Barr virus (EBV)-infected host cells, is a target for adoptive T cell therapy in EBV-associated malignancies. To define whether individual human leukocyte antigen (HLA) allotypes are used preferentially in EBV-specific T lymphocyte responses, LMP2A-specific CD8+ and CD4+ T cell responses in 50 healthy donors were analyzed by ELISPOT assay using artificial Ag-presenting cells expressing a single allotype. CD8+ T cell responses were significantly higher than CD4+ T cell responses. CD8+ T cell responses were ranked from highest to lowest in the order HLA-A, HLA-B, and HLA-C loci, and CD4+ T cell responses were ranked in the order HLA-DR, HLA-DP, and HLA-DQ loci. Among the 32 HLA class I and 56 HLA class II allotypes, 6 HLA-A, 7 HLA-B, 5 HLA-C, 10 HLA-DR, 2 HLA-DQ, and 2 HLA-DP allotypes showed T cell responses higher than 50 spot-forming cells (SFCs)/5×105 CD8+ or CD4+ T cells. Twenty-nine donors (58%) showed a high T cell response to at least one allotype of HLA class I or class II, and 4 donors (8%) had a high response to both HLA class I and class II allotypes. Interestingly, we observed an inverse correlation between the proportion of LMP2A-specific T cell responses and the frequency of HLA class I and II allotypes. These data demonstrate the allele dominance of LMP2A-specific T cell responses among HLA allotypes and their intra-individual dominance in response to only a few allotypes in an individual, which may provide useful information for genetic, pathogenic, and immunotherapeutic approaches to EBV-associated diseases.

20.
J Biol Chem ; 286(8): 6414-22, 2011 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-21156791

RESUMO

Fibulin-5 (FBLN5) belongs to the Fibulin family of secreted extracellular matrix proteins, and our laboratory first established FBLN5 as a novel target for TGF-ß in fibroblasts and endothelial cells. To better understand the pathophysiology of FBLN5, we carried out microarray analysis to identify fibroblast genes whose expressions were regulated by FBLN5 and TGF-ß. In doing so, we identified fibromodulin (Fmod) as a novel target gene of FBLN5, and we validated the differential expression of Fmod and 12 other FBLN5-regulated genes by semi-quantitative real time PCR. Fmod belongs to the small leucine-rich family of proteoglycans, which are important constituents of mammalian extracellular matrices. Interestingly, parental 3T3-L1 fibroblasts displayed high levels of nuclear factor-κB (NF-κB) activity, although those engineered to express Fmod constitutively exhibited significantly reduced NF-κB activity, suggesting that Fmod functions to inhibit NF-κB signaling. By monitoring alterations in the activation of NF-κB and the degradation of its inhibitor, IκBα, we demonstrate for the first time that Fmod contributes to the constitutive degradation of IκBα protein in 3T3-L1 fibroblasts. Mechanistically, we observed Fmod to delay the degradation of IκBα by promoting the following: (i) activation of c-Jun N-terminal kinase; (ii) inhibition of calpain and casein kinase 2 activity; and (iii) induction of fibroblast apoptosis. Taken together, our study identified a novel function for Fmod in directing extracellular signaling, particularly the regulation of NF-κB activity and cell survival.


Assuntos
Apoptose/fisiologia , Proteínas da Matriz Extracelular/metabolismo , Fibroblastos/metabolismo , Proteínas I-kappa B/metabolismo , MAP Quinase Quinase 4/metabolismo , NF-kappa B/metabolismo , Proteoglicanas/metabolismo , Células 3T3-L1 , Animais , Calpaína/genética , Calpaína/metabolismo , Caseína Quinase II/genética , Caseína Quinase II/metabolismo , Sobrevivência Celular/fisiologia , Proteínas da Matriz Extracelular/genética , Fibromodulina , Regulação da Expressão Gênica/fisiologia , Proteínas I-kappa B/genética , MAP Quinase Quinase 4/genética , Camundongos , Inibidor de NF-kappaB alfa , NF-kappa B/genética , Proteoglicanas/genética , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Transdução de Sinais/fisiologia , Fator de Crescimento Transformador beta
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