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1.
J Magn Reson Imaging ; 2024 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-38375988

RESUMO

BACKGROUND: Highly aggressive hepatocellular carcinoma (HCC) is characterized by high tumor recurrence and poor outcomes, but its definition and imaging characteristics have not been clearly described. PURPOSE: To develop and validate a fusion model on gadobenate dimeglumine-enhanced MRI for identifying highly aggressive HCC. STUDY TYPE: Retrospective. POPULATION: 341 patients (M/F = 294/47) with surgically resected HCC, divided into a training cohort (n = 177), temporal validation cohort (n = 77), and multiscanner validation cohort (n = 87). FIELD STRENGTH/SEQUENCE: 3T, dynamic contrast-enhanced MRI with T1-weighted volumetric interpolated breath-hold examination gradient-echo sequences, especially arterial phase (AP) and hepatobiliary phase (HBP, 80-100 min). ASSESSMENT: Clinical factors and diagnosis assessment based on radiologic morphology characteristics associated with highly aggressive HCCs were evaluated. The radiomics signatures were extracted from AP and HBP. Multivariable logistic regression was performed to construct clinical-radiologic morphology (CR) model and clinical-radiologic morphology-radiomics (CRR) model. A nomogram based on the optimal model was established. Early recurrence-free survival (RFS) was evaluated in actual groups and risk groups calculated by the nomogram. STATISTICAL TESTS: The performance was evaluated by receiver operating characteristic curve (ROC) analysis, calibration curves analysis, and decision curves. Early RFS was evaluated by using Kaplan-Meier analysis. A P value <0.05 was considered statistically significant. RESULTS: The CRR model incorporating corona enhancement, cloud-like hyperintensity on HBP, and radiomics signatures showed the highest diagnostic performance. The area under the curves (AUCs) of CRR were significantly higher than those of the CR model (AUC = 0.883 vs. 0.815, respectively, for the training cohort), 0.874 vs. 0.769 for temporal validation, and 0.892 vs. 0.792 for multiscanner validation. In both actual and risk groups, highly and low aggressive HCCs showed statistically significant differences in early recurrence. DATA CONCLUSION: The clinical-radiologic morphology-radiomics model on gadobenate dimeglumine-enhanced MRI has potential to identify highly aggressive HCCs and non-invasively obtain prognostic information. LEVEL OF EVIDENCE: 4 TECHNICAL EFFICACY: Stage 2.

2.
BMC Med Imaging ; 24(1): 48, 2024 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-38373912

RESUMO

INTRODUCTION: The purpose of our study was to differentiate uterine carcinosarcoma (UCS) from endometrioid adenocarcinoma (EAC) by the multiparametric magnetic resonance imaging (MRI) features. METHODS: We retrospectively evaluated clinical and MRI findings in 17 patients with UCS and 34 patients with EAC proven by histologically. The following clinical and pathological features were evaluated: post- or pre-menopausal, clinical presentation, invasion depth, FIGO stage, lymphaticmetastasis. The following MRI features were evaluated: tumor dimension, cystic degeneration or necrosis, hemorrhage, signal intensity (SI) on T2-weighted images (T2WI), relative SI of lesion to myometrium on T2WI, T1WI, DWI, ADCmax, ADCmin, ADCmean (RSI-T2, RSI-T1, RSI-DWI, RSI-ADCmax, RSI-ADCmin, RSI-ADCmean), ADCmax, ADCmin, ADCmean, the maximum, minimum and mean relative enhancement (RE) of lesion to myometrium on the arterial and venous phases (REAmax, REAmin, REAmean, REVmax, REVmin, REVmean). Receiver operating characteristic (ROC) analysis and the area under the curve (AUC) were used to evaluate prediction ability. RESULTS: The mean age of UCS was higher than EAC. UCS occurred more often in the postmenopausal patients. UCS and EAC did not significantly differ in depth of myometrial invasion, FIGO stage and lymphatic metastasis. The anterior-posterior and transverse dimensions were significantly larger in UCS than EAC. Cystic degeneration or necrosis and hemorrhage were more likely occurred in UCS. The SI of tumor on T2WI was more heterogeneous in UCS. The RSI-T2, ADCmax, ADCmean, RSI-ADCmax and RSI-ADCmean of UCS were significantly higher than EAC. The REAmax, REAmin, REAmean, REVmax, REVmin and REVmean of UCS were all higher than EAC. The AUCs were 0.72, 0.71, 0.86, 0.96, 0.89, 0.84, 0.73, 0.97, 0.88, 0.94, 0.91, 0.69 and 0.80 for the anterior-posterior dimension, transverse dimension, RSI-T2, ADCmax, ADCmean, RSI-ADCmax, RSI-ADCmean, REAmax, REAmin, REAmean, REVmax, REVmin and REVmean, respectively. The AUC was 0.997 of the combined of ADCmax, REAmax and REVmax. Our study showed that ADCmax threshold value of 789.05 (10-3mm2/s) can differentiate UCS from EAC with 100% sensitivity, 76.5% specificity, and 0.76 AUC, REAmax threshold value of 0.45 can differentiate UCS from EAC with 88.2% sensitivity, 100% specificity, and 0.88 AUC. CONCLUSION: Multiparametric MRI features may be utilized as a biomarker to distinguish UCS from EAC.


Assuntos
Carcinoma Endometrioide , Carcinossarcoma , Imageamento por Ressonância Magnética Multiparamétrica , Neoplasias Uterinas , Feminino , Humanos , Imagem de Difusão por Ressonância Magnética/métodos , Carcinoma Endometrioide/diagnóstico por imagem , Estudos Retrospectivos , Neoplasias Uterinas/diagnóstico por imagem , Hemorragia , Necrose , Carcinossarcoma/diagnóstico por imagem
3.
Eur Radiol ; 33(1): 633-644, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-35852575

RESUMO

OBJECTIVES: To develop and validate a combined model based on Gd-BOPTA-enhanced MRI to identify advanced liver fibrosis. METHODS: A total of 102 patients with chronic HBV infection were divided into a training cohort (n = 80) and a time-independent testing cohort 1 (n = 22). In the training cohort, radiomics signatures were extracted from the hepatobiliary phase. Model 1 was constructed with clinic-radiological factors using multivariable logistic regression to predict advanced liver fibrosis, and model 2 incorporated radiomics signatures based on model 1. The diagnostic performances were compared with serum fibrosis tests and FibroScan tests using area under curve (AUC) in testing cohort 1. Another 45 patients with other causes were collected in testing cohort 2 for further validation. RESULTS: Model 1 showed age (OR = 1.079) and periportal space widening (OR = 7.838) were the independent factors for predicting advanced fibrosis. After integrating radiomics signatures, model 2 enabled more accurately than model 1 in training cohort (0.940 vs. 0.802, p = 0.003). In testing cohort 1, model 2 demonstrated a superior AUC compared with model 1 (0.900 vs. 0.813,p = 0.131), FibroScan test (0.900 vs. 0.733, p = 0.193), and serum fibrosis tests (APRI and Fib-4 was 0.667 and 0.791). In testing cohort 2, model 2 incorporating radiomics signatures showed satisfactory performance (0.874 vs. 0.757,p = 0.010) compared with model 1. CONCLUSIONS: Radiomics signatures derived from Gd-BOPTA-enhanced HBP images may offer complementary information to the clinic-radiological model for predicting advanced liver fibrosis. KEY POINTS: • Linear or reticular hyperintensity on T2WI, periportal space widening, and diffuse periportal enhancement on HBP can be useful for predicting advanced liver fibrosis. • Clinic-radiological features such as patient age and periportal space widening are the two independent factors predicting advanced fibrosis. • Radiomics signatures derived from Gd-BOPTA-enhanced HBP images offer complementary information to the clinic-radiological model for predicting advanced liver fibrosis.


Assuntos
Cirrose Hepática , Imageamento por Ressonância Magnética , Humanos , Estudos Retrospectivos , Imageamento por Ressonância Magnética/métodos , Cirrose Hepática/diagnóstico por imagem , Fibrose
4.
Genes Immun ; 22(7-8): 327-334, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34864821

RESUMO

Human immunoglobulin G (IgG) molecules, IgG1, IgG2 and IgG3, exhibit substantial inter-individual variation in their constant heavy chain regions, as discovered by serological methods. This polymorphism is encoded by the IGHG1, IGHG2, and IGHG3 genes and may influence antibody function. We sequenced the coding fragments of these genes in 95 European Americans, 94 African Americans, and 94 Black South Africans. Striking differences were observed between the population groups, including extremely low amino acid sequence variation in IGHG1 among South Africans, and higher IGHG2 and IGHG3 diversity in individuals of African descent compared to individuals of European descent. Molecular definition of the loci illustrates a greater level of allelic polymorphism than previously described, including the presence of common IGHG2 and IGHG3 variants that were indistinguishable serologically. Comparison of our data with the 1000 Genome Project sequences indicates overall agreement between the datasets, although some inaccuracies in the 1000 Genomes Project are likely. These data represent the most comprehensive analysis of IGHG polymorphisms across major populations, which can now be applied to deciphering their functional impact.


Assuntos
Imunoglobulina G , Cadeias Pesadas de Imunoglobulinas , Alelos , Genes de Imunoglobulinas , Humanos , Imunoglobulina G/genética , Cadeias Pesadas de Imunoglobulinas/genética , Polimorfismo Genético
5.
Genome Biol Evol ; 16(4)2024 04 02.
Artigo em Inglês | MEDLINE | ID: mdl-38527852

RESUMO

Mammals and birds differ largely in their average endogenous retrovirus loads, namely the proportion of endogenous retrovirus in the genome. The host-endogenous retrovirus relationships, including conflict and co-option, have been hypothesized among the causes of this difference. However, there has not been studies about the genomic evolutionary signal of constant host-endogenous retrovirus interactions in a long-term scale and how such interactions could lead to the endogenous retrovirus load difference. Through a phylogeny-controlled correlation analysis on ∼5,000 genes between the dN/dS ratio of each gene and the load of endogenous retrovirus in 12 mammals and 21 birds, separately, we detected genes that may have evolved in association with endogenous retrovirus loads. Birds have a higher proportion of genes with strong correlation between dN/dS and the endogenous retrovirus load than mammals. Strong evidence of association is found between the dN/dS of the coding gene for leucine-rich repeat-containing protein 23 and endogenous retrovirus load in birds. Gene set enrichment analysis shows that gene silencing rather than immunity and DNA recombination may have a larger contribution to the association between dN/dS and the endogenous retrovirus load for both mammals and birds. The above results together showing different evolutionary patterns between bird and mammal genes can partially explain the apparently lower endogenous retrovirus loads of birds, while gene silencing may be a universal mechanism that plays a remarkable role in the evolutionary interaction between the host and endogenous retrovirus. In summary, our study presents signals that the host genes might have driven or responded to endogenous retrovirus load changes in long-term evolution.


Assuntos
Retrovirus Endógenos , Animais , Retrovirus Endógenos/genética , Aves/genética , Mamíferos/genética , Filogenia , Genômica , Evolução Molecular
6.
Medicine (Baltimore) ; 102(42): e35154, 2023 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-37861563

RESUMO

Septic shock often occurs following critically low blood pressure in patients with sepsis, and is accompanied by a high death rate. Although mitophagy is associated with infection and immune responses, its role in septic shock remains unknown. This study screened effective mitophagy-related genes (MRGs) for medical practice and depicted immune infiltration situations in patients with septic shock. Gene expression profiles of GSE131761 from the Gene Expression Omnibus database were compiled for differential analysis, weighted gene co-expression network analysis, and immune infiltration analysis, while other GSE series were used as validation datasets. A series of validation methods were used to verify the robustness of hub genes, while a nomogram and prognosis model were established for medical practice. Six genes were screened via combinations of differentially expressed genes, weighted gene co-expression network analysis, and MRGs. From this, 3 hub genes (MAP1LC3B, ULK1, and CDC37) were chosen for subsequent analysis based on different validation methods. Gene set enrichment analysis showed that leukocyte trans-endothelial migration and the p53 signaling pathway were abnormally activated during septic shock. Immune infiltration analysis indicated that the imbalance of neutrophils and CD4 naive T cells was significantly correlated with septic shock progression. A nomogram was generated based on MAP1LC3B, ULK1, and CDC37, as well as age. The stability of our model was confirmed using a calibration plot. Importantly, patients with septic shock with the 3 highly expressed hub genes displayed worse prognosis than did patients without septic shock. MAP1LC3B, ULK1, and CDC37 are considered hub MRGs in the development of septic shock and could represent promising diagnostic and prognostic biomarkers in blood tissue. The validated hub genes and immune infiltration pattern expand our knowledge on MRG functional mechanisms, which provides guidance and direction for the development of septic shock diagnostic and therapeutic markers.


Assuntos
Sepse , Choque Séptico , Humanos , Choque Séptico/genética , Mitofagia/genética , Genes Reguladores , Linfócitos T CD4-Positivos
7.
Front Cell Neurosci ; 17: 1237641, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37711511

RESUMO

Spinal cord injury causes varying degrees of motor and sensory function loss. However, there are no effective treatments for spinal cord repair following an injury. Moreover, significant preclinical advances in bioengineering and regenerative medicine have not yet been translated into effective clinical therapies. The spinal cord's poor regenerative capacity makes repairing damaged and lost neurons a critical treatment step. Reprogramming-based neuronal transdifferentiation has recently shown great potential in repair and plasticity, as it can convert mature somatic cells into functional neurons for spinal cord injury repair in vitro and in vivo, effectively halting the progression of spinal cord injury and promoting functional improvement. However, the mechanisms of the neuronal transdifferentiation and the induced neuronal subtypes are not yet well understood. This review analyzes the mechanisms of resident cellular transdifferentiation based on a review of the relevant recent literature, describes different molecular approaches to obtain different neuronal subtypes, discusses the current challenges and improvement methods, and provides new ideas for exploring therapeutic approaches for spinal cord injury.

8.
Abdom Radiol (NY) ; 47(3): 957-968, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-34964069

RESUMO

OBJECTIVE: To identify the reliable imaging features and added-value of ancillary imaging features for differentiating hepatocellular carcinoma (HCC) and intrahepatic mass-forming cholangiocarcinoma (IMCC) assigned to LI-RADS M on Gd-BOPTA-enhanced MRI. METHODS: This retrospective study included 116 liver observations assigned to LI-RADS M, including 82 HCC and 34 IMCC histologically confirmed. Before and after adding ancillary imaging features, all variables with a p-value of < 0.05 in univariable analysis were entered into a multivariable logistic regression analysis to build diagnostic model 1 and model 2 to find reliable predictors of HCC diagnosis. Receiver operating characteristic (ROC) analysis and the DeLong test were used to compare the two models. RESULTS: Forty-nine of 82(59.8%) HCCs had a considerably higher frequency of enhancing "capsule" compared with IMCCs (p < 0.001). Based on LI-RADS major and LR-M features and clinical-pathologic factors, an elevated AFP level (OR = 10.676, 95%CI = 2.125-4.470, p = 0.004) and enhancing "capsule" (OR = 20.558, 95%CI = 4.470-94.550, p < 0.001) were extracted as independent risk factors in Model 1. After adding ancillary imaging features, Male (OR = 23.452, 95%CI = 1.465-375.404, p = 0.026), enhancing "capsule" (OR = 13.161, 95%CI = 1.725-100.400, p = 0.013), septum (OR = 17.983, 95%CI = 1.049-308.181, p = 0.046), small-scale central HBP hyperintensity (OR = 44.386, 95%CI = 1.610-1223.484, p = 0.025) were confirmed as independent significant variables associated with HCC. Model 2 demonstrated significantly superior AUC (0.918 vs 0.845, p = 0.021) compared with Model 1. When any two or more predictors in model 2 were satisfied, sensitivity was 91.46%, and accuracy was at the top (87.93%). CONCLUSION: Enhancing "capsule" was a reliable imaging feature to help identify HCC. Adding ancillary imaging features improved sensitivity and accuracy for HCC diagnosis with differentiation from IMCC in LR-M.


Assuntos
Neoplasias dos Ductos Biliares , Carcinoma Hepatocelular , Colangiocarcinoma , Neoplasias Hepáticas , Neoplasias dos Ductos Biliares/diagnóstico por imagem , Ductos Biliares Intra-Hepáticos/patologia , Carcinoma Hepatocelular/diagnóstico por imagem , Colangiocarcinoma/diagnóstico por imagem , Meios de Contraste , Humanos , Neoplasias Hepáticas/diagnóstico por imagem , Neoplasias Hepáticas/patologia , Imageamento por Ressonância Magnética/métodos , Masculino , Meglumina/análogos & derivados , Compostos Organometálicos , Estudos Retrospectivos , Sensibilidade e Especificidade
9.
Mol Imaging Biol ; 24(6): 973-985, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-35945360

RESUMO

PURPOSE: This study aimed to explore the value of [68Ga]Ga-labelled fibroblast activation protein inhibitor ([68Ga]Ga-FAPI) positron emission tomography/computed tomography (PET/CT) in the initial staging of patients with newly diagnosed nasopharyngeal carcinoma (NPC), compared with 2-deoxy-2[18F]fluoro-D-glucose ([18F]F-FDG) PET/CT. MATERIALS AND METHODS: Forty-seven treatment-naïve patients with newly diagnosed NPC underwent magnetic resonance imaging (MRI), [68Ga]Ga-DOTA-FAPI-04 PET/CT and [18F]F-FDG PET/CT within 1 week. The diagnostic efficiency of all imaging modalities for evaluating primary tumour extension was compared from the two aspects of soft tissue and bony structure involvement. The accuracy of two PET/CT methods for diagnosing cervical lymph node (CLN) metastases was compared, and MRI served as the standard reference. T and N stages were assessed by MRI, [68Ga]Ga-FAPI PET/CT and [18F]F-FDG PET/CT. Immunohistochemical (IHC) staining for FAP was conducted in 22 of the patients. RESULTS: [68Ga]Ga-FAPI PET/CT outperformed [18F]F-FDG PET/CT in the assessment of primary tumour invasion in the cavernous sinus (10 vs. 1, p < 0.001) and bony structures (207 vs. 177, p < 0.001). Compared with MRI, [68Ga]Ga-FAPI PET/CT upgraded and underestimated T stage in 13 and 2 patients, while [18F]F-FDG PET/CT upgraded and underestimated T stage in 5 and 13 patients. However, [68Ga]Ga-FAPI PET/CT was inferior to [18F]F-FDG PET/CT in diagnosing positive CLNs based on the analyses of patients, neck sides, neck levels and individual nodes. [68Ga]Ga-FAPI PET/CT changed therapeutic schedules in 8 patients because of stage group changes. The presence of FAP with high quantity and intensity in cancer-associated fibroblasts (CAFs) was confirmed in all tumour specimens. CONCLUSION: [68Ga]Ga-FAPI PET/CT outperformed [18F]F-FDG PET/CT in detecting the cavernous sinus and bony structure involvement of primary NPC tumours, suggesting its value in improving T staging and therapeutic regimen selection. However, the performance of [68Ga]Ga-FAPI PET/CT is less promising for N staging because it detected fewer positive CLNs than [18F]F-FDG PET/CT.


Assuntos
Neoplasias Nasofaríngeas , Quinolinas , Humanos , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada/métodos , Fluordesoxiglucose F18 , Carcinoma Nasofaríngeo/diagnóstico por imagem , Radioisótopos de Gálio , Metástase Linfática , Neoplasias Nasofaríngeas/diagnóstico por imagem
10.
Genes Genet Syst ; 94(6): 283-300, 2020 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-31827009

RESUMO

The two-dimensional site frequency spectrum (2D SFS) was investigated to describe the intra-allelic variability (IAV) maintained within a derived allele (D) group that has undergone an incomplete selective sweep against an ancestral allele group. We observed that recombination certainly muddles the ancestral relationships of allelic lineages between the two allele groups; however, the 2D SFS reveals intriguing signatures of recombination as well as the genealogical structure of the D group, particularly the size of a mutation and the time to the most recent common ancestor (TMRCA). Coalescent simulations were performed to achieve powerful and robust 2D SFS-based statistics with special reference to accurate evaluation of IAV, significance of recombination effects, and distinction between hard and soft selective sweeps. These studies were extended to a case wherein an incomplete selective sweep is no longer in progress and ceased in the recent past. The 2D SFS-based method was applied to 100 intronic linkage disequilibrium regions randomly chosen from the East Asian population of modern humans to examine the P value distributions of the summary statistics under the null hypothesis of neutrality in a nonequilibrium demographic model. We argue that about 96% of intronic variants are non-adaptive with a 10% false discovery rate. Furthermore, this method was applied to six genomic regions in Eurasian populations that were claimed to have experienced recent selective sweeps. We found that two of these genomic regions did not have significant signals of selective sweeps, but the remaining four had undergone hard and soft sweeps and were dated, in terms of TMRCA, after the major out-of-Africa dispersal of modern humans.


Assuntos
Alelos , Povo Asiático , Interpretação Estatística de Dados , Deriva Genética , Genoma Humano , Humanos , Desequilíbrio de Ligação , Mutação , Polimorfismo de Nucleotídeo Único , Recombinação Genética
11.
Genes (Basel) ; 9(9)2018 Sep 12.
Artigo em Inglês | MEDLINE | ID: mdl-30213147

RESUMO

RIG-I-like receptors (retinoic acid-inducible gene-I-like receptors, or RLRs) are family of pattern-recognition receptors for RNA viruses, consisting of three members: retinoic acid-inducible gene I (RIG-I), melanoma differentiation-associated gene 5 (MDA5) and laboratory of genetics and physiology 2 (LGP2). To understand the role of RLRs in bird evolution, we performed molecular evolutionary analyses on the coding genes of avian RLRs using filtered predicted coding sequences from 62 bird species. Among the three RLRs, conservation score and dN/dS (ratio of nonsynonymous substitution rate over synonymous substitution rate) analyses indicate that avian MDA5 has the highest conservation level in the helicase domain but a lower level in the caspase recruitment domains (CARDs) region, which differs from mammals; LGP2, as a whole gene, has a lower conservation level than RIG-I or MDA5. We found evidence of positive selection across all bird lineages in RIG-I and MDA5 but only on the stem lineage of Galliformes in LGP2, which could be related to the loss of RIG-I in Galliformes. Analyses also suggest that selection relaxation may have occurred in LGP2 during the middle of bird evolution and the CARDs region of MDA5 contains many positively selected sites, which might explain its conservation level. Spearman's correlation test indicates that species-to-ancestor dN/dS of RIG-I shows a negative correlation with endogenous retroviral abundance in bird genomes, suggesting the possibility of interaction between immunity and endogenous retroviruses during bird evolution.

12.
Minerva Anestesiol ; 83(8): 790-797, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28006886

RESUMO

BACKGROUND: Sevoflurane presents reliable central neuromuscular effects. However, little knowledge is available regarding the interaction between sevoflurane and demedetomidine. We evaluated the neuromuscular effect of dexmedetomidine on sevoflurane in patients with normal neuromuscular transmission and calculated the 50% effective concentration (EC50). METHODS: One-hundred and forty-four ASA grade I~II patients with normal neuromuscular transmission, aged 20~60 years old, undergoing lower limbs surgery were enrolled in this open-label, dose-escalation clinical trial. Patients were randomly assigned into 12 groups. Each patient received intravenous 0, 0.5, or 1.0 µg/kg dexmedetomidine 15 min after inhaling 0.7, 1.0, 1.4, or 2.0 MAC sevoflurane. Neuromuscular monitoring was recorded from the adductor pollicis muscle by using acceleromyography with train-of-four (TOF) stimulation of the ulnar nerve (2 Hz every 20 s). TOF ratio was recorded before inhaling sevoflurane, 15 min after keeping constant at target MAC of sevoflurane, 30 min after receiving target dose of dexmedetomidine, and 15 min after sevoflurane washing out. RESULTS: Sevoflurane produced a concentration-dependent decrease in TOF ratio. Mean TOF ratio in 0.7, 1.0, 1.4, and 2.0 MAC groups was 97.9%, 94.9%, 84.7%, and 77.2%, respectively. Neuromuscular EC50 of sevoflurane was 1.31 MAC (95% CI: 1.236~1.388 MAC). Intravenous 0.5 and 1.0 µg/kg dexmedetomidine decreased 3.1% (EC50: 1.27 MAC [95% CI: 1.206~1.327 MAC]) and 10.7% (EC50: 1.17 MAC [95% CI: 1.122~1.217 MAC]) of neuromuscular EC50, respectively. CONCLUSIONS: Sevoflurane has a concentration-dependent central neuromuscular effect in patients with normal neuromuscular transmission. Intravenous dexmedetomidine dose-dependently decreases the neuromuscular EC50 of sevoflurane.


Assuntos
Analgésicos não Narcóticos/farmacologia , Anestésicos Inalatórios/farmacologia , Dexmedetomidina/farmacologia , Junção Neuromuscular/efeitos dos fármacos , Sevoflurano/farmacologia , Adulto , Relação Dose-Resposta a Droga , Interações Medicamentosas , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Monitoração Neuromuscular
13.
Chemosphere ; 84(3): 355-60, 2011 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-21546059

RESUMO

Air samples in four seasons at one site and tree bark samples from four districts were determined to investigate seasonal variation and regional distribution of polybrominated diphenyl ethers (PBDEs) and hexabromocyclododecane (HBCD) in Beijing, China. The total concentrations of PBDEs (∑PBDE) and HBCD (∑HBCD) were in the range of 57-470 and 20-1800 pg m(-3) in the atmosphere, respectively. The ∑PBDE and ∑HBCD concentrations were significantly influenced by the total suspended particulate matter in atmosphere. The total concentrations of PBDEs and HBCD in tree bark samples were in the range of 99-3700 and 26-3400 ng g(-1) lipid weight. It was found that regional distribution of PBDEs and HBCD was related to the function of each district. In addition, the study found that weeping willow bark was an ideal atmospheric PBDEs and HBCD passive sampler. Finally, atmospheric levels of BDE-209 and HBCD at tree bark sampling districts were estimated via applying an established bark/air partitioning model, which had been verified by the measured concentrations in tree bark and atmosphere in Beijing.


Assuntos
Poluentes Atmosféricos/análise , Atmosfera/química , Éteres Difenil Halogenados/análise , Hidrocarbonetos Bromados/análise , Casca de Planta/química , Poluição do Ar/estatística & dados numéricos , China , Monitoramento Ambiental
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