Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 23
Filtrar
Mais filtros

Bases de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
Beijing Da Xue Xue Bao Yi Xue Ban ; 55(3): 480-487, 2023 Jun 18.
Artigo em Zh | MEDLINE | ID: mdl-37291924

RESUMO

OBJECTIVE: To compare the expected population impact of benefit and risk of aspirin treatment strategies for the primary prevention of cardiovascular diseases recommended by different guidelines in the Chinese Electronic Health Records Research in Yinzhou (CHERRY) study. METHODS: A decision-analytic Markov model was used to simulate and compare different strategies of aspirin treatment, including: Strategy ①: Aspirin treatment for Chinese adults aged 40-69 years with a high 10-year cardiovascular risk, recommended by the 2020 Chinese Guideline on the Primary Prevention of Cardiovascular Diseases; Strategy ②: Aspirin treatment for Chinese adults aged 40-59 years with a high 10-year cardiovascular risk, recommended by the 2022 United States Preventive Services Task Force Recommendation Statement on Aspirin Use to Prevent Cardiovascular Disease; Strategy ③: Aspirin treatment for Chinese adults aged 40-69 years with a high 10-year cardiovascular risk and blood pressure well-controlled (< 150/90 mmHg), recommended by the 2019 Guideline on the Assessment and Management of Cardio-vascular Risk in China. The high 10-year cardiovascular risk was defined as the 10-year predicted risk over 10% based on the 2019 World Health Organization non-laboratory model. The Markov model simulated different strategies for ten years (cycles) with parameters mainly from the CHERRY study or published literature. Quality-adjusted life year (QALY) and the number needed to treat (NNT) for each ischemic event (including myocardial infarction and ischemic stroke) were calculated to assess the effectiveness of the different strategies. The number needed to harm (NNH) for each bleeding event (including hemorrhagic stroke and gastrointestinal bleeding) was calculated to assess the safety. The NNT for each net benefit (i.e., the difference of the number of ischemic events could be prevented and the number of bleeding events would be added) was also calculated. One-way sensitivity analysis on the uncertainty of the incidence rate of cardiovascular diseases and probabilistic sensitivity analysis on the uncertainty of hazard ratios of interventions were conducted. RESULTS: A total of 212 153 Chinese adults, were included in this study. The number of people who were recommended for aspirin treatment Strategies ①-③ was 34 235, 2 813, and 25 111, respectively. The Strategy ③ could gain the most QALY of 403 [95% uncertainty interval (UI): 222-511] years. Compared with Strategy ①, Strategy ③ had similar efficiency but better safety, with the extra NNT of 4 (95%UI: 3-4) and NNH of 39 (95%UI: 19-132). The NNT per net benefit was 131 (95%UI: 102-239) for Strategy ①, 256 (95%UI: 181-737) for Strategy ②, and 132 (95%UI: 104-232) for Strategy ③, making Strategy ③ the most favorable option with a better QALY and safety, along with similar efficiency in terms of net benefit. The results were consistent in the sensitivity analyses. CONCLUSION: The aspirin treatment strategies recommended by the updated guidelines on the primary prevention of cardiovascular diseases showed a net benefit for high-risk Chinese adults from developed areas. However, to balance effectiveness and safety, aspirin is suggested to be used for primary prevention of cardiovascular diseases with consideration for blood pressure control, resulting in better intervention efficiency.


Assuntos
Doenças Cardiovasculares , Infarto do Miocárdio , Adulto , Humanos , Aspirina/uso terapêutico , Doenças Cardiovasculares/prevenção & controle , Doenças Cardiovasculares/epidemiologia , Hemorragia Gastrointestinal , Infarto do Miocárdio/prevenção & controle , Prevenção Primária/métodos , Pessoa de Meia-Idade , Idoso
2.
Nanotechnology ; 31(20): 205302, 2020 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-31995533

RESUMO

The magnetic vortex, as one of the most interesting magnetic solitons, has attracted great interest over the past two decades. A fast and reliable method to switch vortex polarity and chirality is one of the key issues for various applications. Based on micromagnetic simulation, here we report a fast, low energy cost and deterministic switching of a vortex core, by the designing of a notch structure in disks and the use of out-of-plane current geometry. We demonstrate that with such a design, the multiple switching problems found in notch disk systems can be avoided. Furthermore, the switching time can be reduced by more than 50% compared with disks without notches.

3.
J Biol Regul Homeost Agents ; 33(5): 1437-1449, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31637902

RESUMO

Influenza has frequently been epidemic in recent years. However, the mechanisms of severe pneumonia with postinfluenza Streptococcus pneumoniae (SP) secondary infection have not been fully understood. In this study, we explored the mechanisms of pneumonia in postinfluenza A virus (IAV) infection via a mouse model. Mice were intranasally inoculated with SP three days after IAV inoculation. We then collected samples at three time points to dynamically observe the pathological progression. In IAV infection alone, lymphocyte infiltration and widened alveolar intervals were observed. In the blood, levels of the CD19+, CD19+CD21+ and CD19+CD79ß+B lymphocyte subpopulations were reduced, and IFN-γ and IL-10 were elevated. Slight atrophy was seen in the spleen, which was due to splenic B lymphocyteinitiated apoptosis through the mitochondrial pathway. When SP infection occurred after IAV infection, the pulmonary inflammation was significantly aggravated; a fair number of lymphocytes and neutrophils infiltrated simultaneously with exfoliated bronchial epithelial cells, vascular endothelial cells, widened alveolar septum and hemorrhaging. Increasing edema fluid and bacteria accumulated in the alveolar cavity. Decreased CD19+, CD19+CD21+ and CD19+CD79ß+B lymphocyte subpopulations and increased interferon gamma (IFN-γ) or interleukin 10 (IL-10) were more prominent compared to those with viral infection alone. Spleen atrophy resulting from coinfection was more obvious because of massive splenic B lymphocyte apoptosis through the mitochondrial pathway compared to viral infection alone. This study shows that although inflammation caused by SP infection alone was temporary, preceding IAV infection provided favorable conditions for SP colonization and multiplication by destroying lung structure and suppressing humoral immunity. Synergistic IAV-SP coinfection is likely to facilitate more SP colonization and promote B lymphocyte-suppression and reduction. Eventually, the pneumonia worsened.


Assuntos
Linfócitos B/imunologia , Infecções por Orthomyxoviridae/imunologia , Infecções Pneumocócicas/imunologia , Pneumonia Bacteriana/imunologia , Animais , Apoptose , Linfócitos B/citologia , Coinfecção/microbiologia , Coinfecção/virologia , Células Endoteliais , Vírus da Influenza A , Pulmão , Camundongos , Infecções por Orthomyxoviridae/microbiologia , Infecções Pneumocócicas/virologia , Streptococcus pneumoniae
4.
Nanotechnology ; 27(45): 455705, 2016 Nov 11.
Artigo em Inglês | MEDLINE | ID: mdl-27713181

RESUMO

Replacing Ir with Rh in a CoIr system possessing negative uniaxial magnetocrystalline anisotropy (K u ) substantially reduces its magnetic damping and coercivity by more than half while retaining its high negative K u . Moreover, a higher saturation magnetization (M s ) and more isotropic coercivity are achieved. Such material development makes it particularly suitable for use as the soft underlayer (SUL) of magnetic recording media for reducing noise, and as the oscillation layer of a spin-torque oscillator (STO) for achieving higher oscillation frequency, larger AC magnetic field and lower driving current, which can be readily integrated with the current recording head for microwave-assisted magnetic recording. Finally, we recommend a composite free layer by coupling CoIr with a spin polarizer (Co or Co/Cu/Co) for the enhancement of the spin-polarization rate and, therefore, the improvement of STO efficiency. These could pave the way for CoIr-based materials to be implemented in devices requiring a negative Ku with low damping and high 'softness', such as oscillators.

5.
Genet Mol Res ; 15(1): 15017396, 2016 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-26985936

RESUMO

In this study, the existence of vasculogenic mimicry (VM) in cervical squamous cell carcinoma was investigated. To this end, the relationship between hypoxia-inducible factor 1α (HIF-1α) and the development, infiltration, and metastasis of cervical squamous cell carcinoma was studied. Between January 2010 and December 2010, 67 human cervical squamous carcinoma tissue samples were collected and stained by CD34/periodic acid-Schiff double staining to detect the existence of VM. HIF-1α expression was analyzed by immunohistochemistry. The relationship between VM and HIF-1α was also analyzed. Normal cervical tissues (20 cases) from patients who had uterine surgeries in the same period were collected as controls. In the cervical squamous carcinoma tissues, positive rates of VM and HIF-1α were 38.81% (26/67) and 64.18% (43/67), respectively. This was significantly higher than those in the normal cervical tissues [0 (0/20); P < 0.05]. VM rates in cervical squamous carcinoma tissues from patients with different pathological grades, Federation of Gynecology and Obstetrics (FIGO) stages, and lymph node metastasis states were also significantly different (P < 0.05). In addition, significant differences in HIF-1α positivity rates were observed among patients with varying tumor sizes and lymph node metastasis states (P < 0.05). Positive correlation was found between VM and HIF-1α (r = 0.339, P < 0.05). To summarize, we found VM in cervical squamous carcinoma; high expression of HIF-1α may promote VM formation, as well as cervical squamous cell infiltration and metastasis.


Assuntos
Carcinoma de Células Escamosas/irrigação sanguínea , Expressão Gênica , Oxigenases de Função Mista/genética , Neovascularização Patológica , Proteínas Repressoras/genética , Neoplasias do Colo do Útero/irrigação sanguínea , Adulto , Idoso , Carcinoma de Células Escamosas/metabolismo , Carcinoma de Células Escamosas/patologia , Carcinoma de Células Escamosas/secundário , Feminino , Humanos , Metástase Linfática , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Neoplasias do Colo do Útero/metabolismo , Neoplasias do Colo do Útero/patologia , Adulto Jovem
6.
Spinal Cord ; 52(7): 564-9, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24861703

RESUMO

STUDY DESIGN: A prospective study. OBJECTIVES: To evaluate the effect of the surgery to reconstruct thoracic breathing in patients with high cervical spinal cord injury (CSCI). SETTING: China Rehabilitation Research Center, Beijing, China. METHODS: The posterior ribs (from the fifth to the eighth) were suspended on the inferior angle of the scapula on each side using titanium cables, as well as muscles and myofascial tissue in the subscapular area. After the surgery, the patients were trained for synchronous contraction of the trapezius and diaphragm muscles, and electromyography (EMG) was performed to evaluate the synchronization. The clinical symptoms and pulmonary function were assessed within 1 week before surgery and at 2, 12 and 24 postoperative weeks. RESULTS: Six patients with complete high CSCI received rib suspension surgery 84±26.7 days after spinal cord injury. Before the surgery, all of the patients presented with weakened cough, retention of respiratory secretions and dyspnea, while these symptoms alleviated postoperatively. The vital capacity (VC) was enhanced to be 1680±282 ml at 2 weeks after the surgery, compared with 1085±92 ml (P=0.013). The EMG showed a synchronous muscle electrical activity between the trapezius muscles and diaphragm during deep breaths. CONCLUSION: The rib suspension surgery partially restored the thoracic breathing of the patients with high CSCI, thereby improving VC, cough and expectoration.


Assuntos
Medula Cervical/lesões , Transtornos Respiratórios/reabilitação , Transtornos Respiratórios/cirurgia , Respiração , Costelas/cirurgia , Traumatismos da Medula Espinal/reabilitação , Traumatismos da Medula Espinal/cirurgia , Músculos Abdominais/fisiopatologia , Adolescente , Adulto , Tosse , Diafragma/fisiopatologia , Eletromiografia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Exame Neurológico , Procedimentos Ortopédicos/efeitos adversos , Transtornos Respiratórios/etiologia , Transtornos Respiratórios/fisiopatologia , Testes de Função Respiratória , Traumatismos da Medula Espinal/complicações , Traumatismos da Medula Espinal/fisiopatologia , Fatores de Tempo , Resultado do Tratamento , Capacidade Vital
7.
J Nanosci Nanotechnol ; 11(3): 2665-8, 2011 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-21449450

RESUMO

FeTaC magnetic soft underlayer under elevated temperature process conditions for L1(0) FePt based perpendicular recording media has been investigated. After annealing FeTaC for 40 min at 350 degrees C, saturation moment increases to 750 emu/cm3 and, coercivity and remanent moment reduce to 2.3 Oe and 166 emu/cm3 respectively. The microstructure of FeTaC annealed at 350 degrees C for 40 min composes of Fe nanocrystals with random orientations immersed in an amorphous matrix. FeTaC surface roughness due to elevated temperature process is reduced by 100 W RF plasma etching and CrRu with (200) orientation is developed. It is found that changing elemental composition due to C diffusion into the CrRu layer and RF preferential etching over Fe, Ta and C has the influence on the magnetic properties of FeTaC.


Assuntos
Ferro/química , Nanoestruturas/química , Nanoestruturas/ultraestrutura , Platina/química , Gravação de Videoteipe/instrumentação , Cristalização/métodos , Desenho de Equipamento , Análise de Falha de Equipamento , Teste de Materiais , Tamanho da Partícula
8.
J Nanosci Nanotechnol ; 11(3): 2588-92, 2011 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-21449432

RESUMO

In this report, the effect of simultaneously adding two dopants (C and Ta2O5) in FePt was investigated. (Fe55Pt45)79C21-(x vol%) Ta2O5 films (where x = 0% to 20%) were prepared using both low and high power magnetron sputtering on MgO (2 nm)/CrRu (30 nm) underlayers with in-situ heating at 350 degrees C. Films deposited at low power showed a decrease in exchange coupling with increasing Ta2O5 content. Out-of-plane coercivity of 7.2 kOe was observed even with up to 20 vol% Ta2O5. X-Ray diffraction spectra showed presence of FePt(001) texture for all compositions of Ta2O5 ranging from 0 to 20 vol% suggesting that the perpendicular anisotropy was maintained even with up to 20 vol% of dopant content. Films deposited at high power showed a different behavior with an initial increase in out-of-plane coercivity to 8.2 kOe and a reduction in exchange coupling with loop slope parameter (alpha) approaching a fully decoupled value of 1. Further increase in doping content led to deterioration in the out-of-plane coercivity, as well as an increase in the exchange coupling.


Assuntos
Carbono/química , Ferro/química , Magnetismo/instrumentação , Nanoestruturas/química , Óxidos/química , Platina/química , Tantálio/química , Desenho de Equipamento , Análise de Falha de Equipamento , Nanoestruturas/ultraestrutura , Tamanho da Partícula
9.
Phys Rev E ; 103(6-1): 062119, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-34271735

RESUMO

With the stochastic Landau-Lifshitz-Gilbert equation, we numerically simulate the creep motion of a magnetic domain wall driven by the adiabatic and nonadiabatic spin-transfer torques induced by the electric current. The creep exponent µ and the roughness exponent ζ are accurately determined from the scaling behaviors. The creep motions driven by the adiabatic and nonadiabatic spin-transfer torques belong to different universality classes. The scaling relation between µ and ζ based on certain simplified assumptions is valid for the nonadiabatic spin-transfer torque, while invalid for the adiabatic one. Our results are compatible with the experimental ones, but go beyond the existing theoretical prediction. Our investigation reveals that the disorder-induced pinning effect on the domain-wall rotation alters the universality class of the creep motion.

10.
Lin Chuang Er Bi Yan Hou Tou Jing Wai Ke Za Zhi ; 31(24): 1880-1883, 2017 Dec 20.
Artigo em Zh | MEDLINE | ID: mdl-29798308

RESUMO

Objective:To investigate the predictive value of parathyroid hormone levels and decreases for postoperative hypocalcemia after total thyroidectomy. Method:We reviewed 71 consecutive patients who underwent total thyroidectomy, measured postoperative hypocalcemia, parathyroid hormone (PTH) values within 24 hours after surgery, divided them into subgroups accroding to hypocalcemia symptom. Combining with postoperative serum calcium,postoperative PTH values and decreases (△PTH), we used the receiver operating characteristic curve (ROC) analysis to assessment of predictive value. Result:The mean value of postoperative serum calcium, postoperative PTH and △PTH between subgroups have a significant difference (P<0.01). ROC area under the curve (AUC) of △PTH is 0.9706, with cutoff value 0.7366. AUC of postoperative PTH is 0.9580, with cutoff value 14.82 ng/L. Conclusion:The postoperative PTH and △PTH is a reliable indicator to judging postoperative hypocalcemia after total thyroidectomy.


Assuntos
Hipocalcemia , Hormônio Paratireóideo/sangue , Tireoidectomia/efeitos adversos , Cálcio , Humanos , Complicações Pós-Operatórias , Período Pós-Operatório , Curva ROC
11.
Sci Rep ; 7(1): 16208, 2017 11 24.
Artigo em Inglês | MEDLINE | ID: mdl-29176632

RESUMO

Precise control of domain wall displacement in nanowires is essential for application in domain wall based memory and logic devices. Currently, domain walls are pinned by creating topographical notches fabricated by lithography. In this paper, we propose localized diffusion of non-magnetic metal into ferromagnetic nanowires by annealing induced mixing as a non-topographical approach to form pinning sites. As a first step to prove this new approach, magnetodynamic properties of permalloy (Ni80Fe20) films coated with different capping layers such as Ta, Cr, Cu and Ru were investigated. Ferromagnetic resonance (FMR), and anisotropy magnetoresistance (AMR) measurements were carried out after annealing the samples at different temperatures (T an ). The saturation magnetization of Ni80Fe20 film decreased, and damping constant increased with T an . X-Ray photoelectron spectroscopy results confirmed increased diffusion of Cr into the middle of Ni80Fe20 layers with T an . The resistance vs magnetic field measurements on nanowires showed intriguing results.

12.
J Anim Sci ; 93(7): 3503-11, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-26440019

RESUMO

Polyamines are essential for embryonic and fetal survival, growth, and development. Additionally, polyamines may induce autophagy in mammalian cells. However, little is known about the availability of polyamines or autophagy in the porcine conceptus with intrauterine growth restriction (IUGR). The present study was performed to evaluate the developmental changes of polyamine concentrations in IUGR and normal porcine fetuses as well as autophagic marker levels in the fetal intestinal mucosa during the second half of gestation when most fetal growth occurs. Allantoic fluid (ALF), amniotic fluid (AMF), umbilical vein, and the small-intestinal mucosa were obtained from both IUGR and normal fetal pigs at d 60, 90, and 110 of gestation. Concentrations of polyamines in fetal fluids as well as protein abundances of microtubule-associated protein light chain 3B (LC3B), an autophagic marker, in the fetal small-intestinal mucosa were determined. Concentrations of polyamines varied greatly in different fetal compartments and changed substantially with advancing gestation. Concentrations of polyamines in IUGR fetal fluids and the small-intestinal mucosa were markedly different from those in their normal counterparts at d 60 and 90 of gestation, whereas most of the differences were not detected by late (d 110) gestation. Specifically, polyamine levels were lower in the umbilical vein plasma but higher in ALF and AMF from IUGR fetuses. Furthermore, enhanced levels of an autophagic marker were observed in the small-intestinal mucosa of IUGR fetuses throughout mid and late gestation in association with abnormal spermidine levels in fetal plasma. These findings support the notion that enhanced autophagy may be an important survival mechanism in IUGR fetuses. Collectively, our findings provide a new framework for future studies to define the roles for polyamines in the prevention and treatment of IUGR in both human medicine and animal production.


Assuntos
Retardo do Crescimento Fetal/veterinária , Poliaminas/metabolismo , Suínos/crescimento & desenvolvimento , Líquido Amniótico , Animais , Biomarcadores , Restrição Calórica , Feminino , Desenvolvimento Fetal , Transtornos da Nutrição Fetal , Humanos , Mucosa Intestinal/metabolismo , Intestino Delgado/metabolismo , Fenômenos Fisiológicos da Nutrição Materna , Gravidez
13.
Zhonghua Zhong Liu Za Zhi ; 9(3): 236-7, 10, 1987 May.
Artigo em Zh | MEDLINE | ID: mdl-3482202

RESUMO

Telangiectatic osteosarcoma, being a subtype of osteosarcoma, is rare. In this paper, one case is reported. The patient, a sixteen year old man, was admitted into our hospital in 1983 because of swelling and pain in the left knee for 3 months. On physical examination, a mass, 7 x 5 x 5 cm in size, was found in the distal end of the left thigh. A misdiagnosis of hemangioma of the bone was made by puncture biopsy before operation. After three months, the disease progressed and amputation had to be performed. The pathological diagnosis of telangiectatic osteosarcoma was established after operation. Finally, clinical and roentgenographic manifestations, histological and ultrastructural findings, biologic behavior, diagnosis and differential diagnosis are discussed. In particular, the differentiation from aneurysmal bony cyst and hemangioma of the bone is emphasized.


Assuntos
Neoplasias Femorais/diagnóstico , Osteossarcoma/diagnóstico , Adolescente , Diagnóstico Diferencial , Neoplasias Femorais/ultraestrutura , Humanos , Masculino , Osteossarcoma/ultraestrutura
14.
Zhonghua Wai Ke Za Zhi ; 27(8): 482-3, 510, 1989 Aug.
Artigo em Zh | MEDLINE | ID: mdl-2620605

RESUMO

The writers had investigated 307 patients with paraplegia caused by Tangshan earthquake on July 28, 1976 and analysed their renograms. The results showed that the incidence of the abnormal renogram was 22.8% and significantly higher in the males and the patients with urinary incontinence than in the females and patients with urinary regularly. The renography was compared with the ultrasonography and their coincidence ratio was 93.5%. The relation among the abnormal renogram, urinary incontinence and sex is discussed.


Assuntos
Rim/fisiopatologia , Paraplegia/fisiopatologia , Adulto , Idoso , China , Desastres , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Paraplegia/diagnóstico por imagem , Paraplegia/etiologia , Renografia por Radioisótopo , Traumatismos da Medula Espinal/complicações
16.
Anesth Analg ; 92(6): 1569-75, 2001 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-11375848

RESUMO

We assessed the analgesic efficacy of IV propacetamol and ketorolac in a double-blinded, placebo-controlled study involving patients undergoing total hip or knee replacement procedures. On the first morning after major joint replacement surgery, 164 patients experiencing moderate-to-severe pain were randomly assigned to receive an IV infusion of propacetamol (2 g), ketorolac (15 or 30 mg), or placebo (saline). Patient-controlled analgesia with morphine was made available as a "rescue" analgesic on patient's request during the 6-h postdosing evaluation period. The median time to onset of analgesia with propacetamol (8 [95% confidence interval 6,10] min) was shorter than ketorolac 15 mg (14 [7,16] min), and placebo (16 [8; not estimable] min) although the differences did not reach statistical significance. However, compared with ketorolac 30 mg, propacetamol had a shorter duration of analgesia (3.5 [2;5.4] vs 6 [3.3; not estimable] h). Analysis of pain intensity and pain relief scores demonstrated that propacetamol produced a significantly greater improvement in pain relief than saline from 45 min until 5 h after the injection. Propacetamol was not significantly different from ketorolac 15 mg and 30 mg with respect to the main analgesic efficacy variables during the 6-h assessment period. The most frequently reported adverse event with propacetamol was injection site pain (28% vs 19% for ketorolac 15 mg, 29% for ketorolac 30 mg, and 10% for placebo, respectively). In conclusion, propacetamol (2 g IV) possesses a similar analgesic efficacy to ketorolac (15 or 30 mg IV) after total hip or knee replacement surgery.


Assuntos
Acetaminofen/análogos & derivados , Acetaminofen/uso terapêutico , Analgésicos não Narcóticos/uso terapêutico , Artroplastia de Quadril , Artroplastia do Joelho , Cetorolaco/uso terapêutico , Dor Pós-Operatória/tratamento farmacológico , Idoso , Analgesia Controlada pelo Paciente , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Medição da Dor/efeitos dos fármacos , Fatores de Tempo
17.
Acta Anaesthesiol Scand ; 45(2): 246-9, 2001 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-11167172

RESUMO

BACKGROUND: The use of volatile anesthetics for maintenance of anesthesia can enhance the action of non-depolarizing muscle relaxants and interfere with the reversal of neuromuscular blockade. In this study, we studied the antagonism of rocuronium with edrophonium-atropine during propofol- versus sevoflurane-based anesthesia. METHODS: Following induction of anesthesia with propofol (2-2.5 mg kg(-1), i.v.) and fentanyl (1-2 microg kg(-1) i.v.), rocuronium 0.6 mg kg(-1) i.v. was administered to facilitate tracheal intubation. Patients were then randomized to receive either a propofol infusion (100 microg kg(-1) min(-1)) or sevoflurane (1.0%, end-tidal) in combination with nitrous oxide 66% for maintenance of anesthesia. Neuromuscular blockade was monitored using electromyography at the wrist, and reversed with edrophonium 1.0 mg kg(-1) and atropine 0.015 mg kg(-1) when the first twitch hight (T1) of the train-of-four (TOF) stimulation recovered to 25% of the baseline value. Anesthetic maintenance with propofol or sevoflurane was continued following reversal until a TOF ratio of 0.7 was attained. RESULTS: The clinical duration of action (i.e., time to 25% T1 recovery) was similar during both propofol- (39.3+/-14.6 min) and sevoflurane-based (48.1+/-19.7 min) anesthesia. However, the reversal time from 25% T1 to TOF ratio of 0.7 was significantly longer with sevoflurane [Median 2.8 (range 0.5-18.8) min] compared with propofol [1.5 (0.75-3) min] (P<0.05). CONCLUSIONS: We conclude that the clinical duration of action after a single dose of rocuronium, 0.6 mg kg(-1) i.v., was similar during both propofol- and sevoflurane-based anesthesia. However, the reversal of rocuronium-induced residual blockade was slower and more variable in the presence of sevoflurane.


Assuntos
Androstanóis/antagonistas & inibidores , Anestesia Geral , Anestésicos Inalatórios , Anestésicos Intravenosos , Edrofônio/uso terapêutico , Éteres Metílicos , Fármacos Neuromusculares não Despolarizantes/antagonistas & inibidores , Propofol , Adolescente , Adulto , Idoso , Procedimentos Cirúrgicos Eletivos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Procedimentos Ortopédicos , Rocurônio , Sevoflurano
18.
Br J Anaesth ; 85(2): 246-50, 2000 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-10992833

RESUMO

We compared onset and offset of action and tracheal intubating conditions after rapacuronium and rocuronium in 60 patients in a randomized, assessor-blinded study. Following induction of anaesthesia with propofol 2.5 mg kg-1, either rapacuronium 1.5 mg kg-1 (n = 30) or rocuronium 0.6 mg kg-1 (n = 30) was administered to facilitate tracheal intubation. Anaesthesia was maintained with either a propofol infusion (100 micrograms kg-1 min-1) or sevoflurane (1% end-tidal) with 66% nitrous oxide (N2O), n = 15 in each subgroup. Neuromuscular monitoring was performed using an electromyographic (EMG) device (Datex Relaxograph). The lag times (mean 42 (SD 11) s and 44 (16) s), maximum block (99 (2)% and 98 (3)%) and intubating conditions at 60 s (good-to-excellent in 86% and 84% of patients) were similar for rapacuronium and rocuronium, respectively. The onset time of rapacuronium was shorter than rocuronium (87 (20) vs 141 (65) s, P < 0.001), and the degree of block at 60 s was greater (69 (26) vs 50 (27)%, P < 0.05). Twenty-five per cent recovery was shorter with rapacuronium than rocuronium during propofol (15.0 (3.2) vs 39.1 (14.2) min, P < 0.001) and sevoflurane (15.1 (4.2) vs 47.8 (19.0) min, P < 0.001) anaesthesia. We conclude that rapacuronium 1.5 mg kg-1 had a more rapid onset, similar intubating conditions, and shorter recovery times than rocuronium 0.6 mg kg-1.


Assuntos
Androstanóis/farmacologia , Intubação Intratraqueal , Fármacos Neuromusculares não Despolarizantes/farmacologia , Brometo de Vecurônio/análogos & derivados , Adulto , Idoso , Anestésicos Inalatórios/administração & dosagem , Anestésicos Intravenosos/administração & dosagem , Eletromiografia/efeitos dos fármacos , Enflurano/administração & dosagem , Enflurano/análogos & derivados , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Propofol/administração & dosagem , Rocurônio , Método Simples-Cego , Brometo de Vecurônio/farmacologia
19.
Anesth Analg ; 91(3): 596-600, 2000 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-10960383

RESUMO

UNLABELLED: We evaluated the spontaneous recovery characteristics of rapacuronium during desflurane-, sevoflurane-, or propofol-based anesthesia in 51 consenting women undergoing laparoscopic tubal ligation procedures. After the induction of the anesthesia with standardized doses of propofol and fentanyl, 1.5 mg/kg IV rapacuronium was administered to facilitate tracheal intubation. Patients were randomized to receive either 1 minimum alveolar anesthetic concentration of desflurane, 1 minimum alveolar concentration of sevoflurane, or 100 microg. kg(-1). min(-1) propofol infusion in combination with 66% nitrous oxide in oxygen for maintenance of anesthesia. Neuromuscular blockade was monitored at the wrist by using electromyography. The degree of maximum blockade and the times for first twitch recovery (T(1)) to 5%, 25%, 50%, 75%, and 90%, as well as the recovery index, were similar in all three anesthetic groups. However, recovery times for the train-of-four ratio to achieve 0.7 and 0.8 were significantly longer with desflurane (44.4 +/- 18.9 and 53.5 +/- 22.4 min) and sevoflurane (44.8 +/- 15.1 and 53.2 +/- 15.8 min) compared with propofol (31.8 +/- 5.3 and 36.5 +/- 6.5 min). Eight patients (16%) required a maintenance dose of 0.5 mg/kg rapacuronium and reversal of rapacuronium residual block occurred in three (6%) patients. We conclude that spontaneous recovery after an intubating dose of 1.5 mg/kg rapacuronium was significantly prolonged by both desflurane and sevoflurane compared with propofol-based anesthesia. Routine monitoring of neuromuscular activity is recommended even when a single bolus dose of rapacuronium is administered during ambulatory anesthesia. IMPLICATIONS: When administered for laparoscopic surgery, the duration of action of an intubating dose of rapacuronium was prolonged 40%-50% by desflurane and sevoflurane, respectively, (versus propofol). Monitoring recovery of neuromuscular blockade produced by rapacuronium is particularly important when desflurane or sevoflurane is administered to ensure that an adequate recovery (train-of-four > or = 0.8) is achieved by the end of anesthesia.


Assuntos
Procedimentos Cirúrgicos Ambulatórios , Anestésicos Inalatórios , Anestésicos Intravenosos , Isoflurano/análogos & derivados , Laparoscopia , Éteres Metílicos , Fármacos Neuromusculares não Despolarizantes , Propofol , Brometo de Vecurônio/análogos & derivados , Adulto , Desflurano , Método Duplo-Cego , Feminino , Humanos , Pacientes Ambulatoriais , Estudos Prospectivos , Sevoflurano , Esterilização Tubária
20.
Acta Neurol Scand ; 86(3): 329-31, 1992 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-1414256

RESUMO

Blood superoxide dismutase (SOD) activity and blood copper, zinc-superoxide dismutase (Cu.Zn-SOD) content were measured by luminol chemiluminescence assay and by single radial immunodiffusion assay, respectively, in 50 patients with paraplegia due to traumatic injury to the spinal cord by the Tangshan Earthquake on July 28, 1976, compared with 20 age-matched healthy subjects. We found that blood SOD activity and blood Cu.Zn-SOD content in the paraplegic patients were significantly lower than those in healthy subjects (p < 0.01). In healthy subjects, blood Cu.Zn-SOD fully expressed the enzymatic activity, whereas only 77% of blood Cu.Zn-SOD in the paraplegic patients expressed the enzymatic activity, indicating that in the patients, part of blood Cu.Zn-SOD protein is in a state without function. Also the serum lipid peroxide level in the paraplegic patients was higher than that in healthy subjects (p < 0.05). These findings suggest decreased endogenous blood protection against oxygen derived free radicals in these paraplegic patients.


Assuntos
Peroxidação de Lipídeos/fisiologia , Paraplegia/enzimologia , Traumatismos da Medula Espinal/enzimologia , Superóxido Dismutase/sangue , Adulto , Idoso , Feminino , Radicais Livres , Humanos , Masculino , Pessoa de Meia-Idade
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA