Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 48
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Zhongguo Zhong Yao Za Zhi ; 46(12): 2912-2922, 2021 Jun.
Artigo em Chinês | MEDLINE | ID: mdl-34467681

RESUMO

The dried fruit body of Phylloporia ribis(Hymenochaetaceae), which prefers to live on the stumps of Lonicera japonica(Caprifoliaceae), has a variety of activities, whereas its pharmacodynamic material basis is not completely clear and there are few reports on its quality control and evaluation. In this study, an UPLC-Q-TOF-MS method was used to analyze the nucleosides and nucleobases in P. ribis and a HPLC method was established for simultaneous determination of 10 nucleosides and nucleobases. MS and MS/MS data were acquired in positive ion mode. Based on the data comparison of the sample and the reference substance, the literature data and the compound databases of ChemSpider and PubChem, 18 nucleosides and nucleobases were identified qualitatively from the water extract of P. ribis for the first time. After optimization, the HPLC was performed using a Welch Ultimate AQ C_(18) column(4.6 mm×250 mm, 5 µm) by gradient elution with acetonitrile and water as mobile phase, the flow rate of 1.0 mL·min~(-1), the detection wavelength of 260 nm, and the column temperature of 30 ℃. Through the investigation of the extraction method, solvent and time, it was determined that the test solution should be obtained by cold water extraction for 18 h. At the present HPLC conditions, 10 components of uracil, cytidine, hypoxanthine, uridine, thymine, inosine, guanosine, 2'-deoxyinosine, 2'-deoxyguanosine and thymidine could be well separated(R > 1.5) and showed good linearity(r > 0.999 9) in the concentration ranges of 0.247-24.7, 0.283-28.3, 0.273-27.3, 0.256-25.6, 0.257-25.7, 0.318-31.8, 0.245-24.5, 0.267-26.7, 0.250-25.0 and 0.267-26.7 mg·L~(-1), respectively. The average reco-veries of 10 components were 95.78%-104.5%, and the RSDs were 2.2%-5.2%(n=6). The contents of 10 nucleosides and nucleobases in different samples of P. ribis varied greatly, which were 0.021-0.122, 0.004-0.029, 0.014-0.226, 0.009-0.442, 0.003-0.014, 0.002-0.146, 0.007-0.098, 0-0.054, 0.005-0.069, 0.004-0.081 and 0.072-1.28 mg·g~(-1) for uracil, cytidine, hypoxanthine, uridine, thymine, inosine, guanosine, 2'-deoxyinosine, 2'-deoxyguanosine, thymidine and total 10 components, respectively. These results demonstrated that the components had significant differences in the internal quality, and good quality control was needed to ensure the medical efficacy. This study provides a scientific basis for the discovery of pharmacodynamic ingredients, quality control and evaluation of P. ribis.


Assuntos
Nucleosídeos , Espectrometria de Massas em Tandem , Basidiomycota , Cromatografia Líquida de Alta Pressão , Guanosina
2.
Adv Mater ; 33(34): e2008267, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34240474

RESUMO

Recently, sensors that can imitate human skin have received extensive attention. Capacitive sensors have a simple structure, low loss, no temperature drift, and other excellent properties, and can be applied in the fields of robotics, human-machine interactions, medical care, and health monitoring. Polymer matrices are commonly employed in flexible capacitive sensors because of their high flexibility. However, their volume is almost unchanged when pressure is applied, and they are inherently viscoelastic. These shortcomings severely lead to high hysteresis and limit the improvement in sensitivity. Therefore, considerable efforts have been applied to improve the sensing performance by designing different microstructures of materials. Herein, two types of sensors based on the applied forces are discussed, including pressure sensors and strain sensors. Currently, five types of microstructures are commonly used in pressure sensors, while four are used in strain sensors. The advantages, disadvantages, and practical values of the different structures are systematically elaborated. Finally, future perspectives of microstructures for capacitive sensors are discussed, with the aim of providing a guide for designing advanced flexible and stretchable capacitive sensors via ingenious human-made microstructures.

3.
Zhongguo Zhong Yao Za Zhi ; 46(6): 1339-1344, 2021 Mar.
Artigo em Chinês | MEDLINE | ID: mdl-33787130

RESUMO

Chrysanthemum is widely used as a type of edible flower and also considered as the important materials of many beverages in China. Due to the occurrence of diseases and pests, and the lack of regulations for species, frequency, dose of pesticides in Chrysanthemum, pesticides have become one of the main pollutants in Chrysanthemum. The pesticide residues in Chrysanthemum were detected frequently and worth noting. This paper focused on the types of pesticides, pesticide residue detection techniques, and risk assessment methods for Chrysanthemums on the basis of relevant literatures. The pesticide residues of traditional Chinese medicine are mainly organochlorines, organophosphorus and pyrethroids, and the detection techniques include gas chromatography(GC), liquid chromatography(LC) or both combined with mass spectrometry(MS). With the increasing use of traditional Chinese medicine, Chrysanthemum is widely circulated in the market. Therefore, it is important to understand the current situation of pesticide residues in different varieties of Chrysanthemum, so as to provide theoretical reference for the control of quality and safety of Chrysanthemum and the formulation of the maximum residue limit.


Assuntos
Chrysanthemum , Resíduos de Praguicidas , China , Cromatografia Líquida , Chrysanthemum/genética , Cromatografia Gasosa-Espectrometria de Massas , Resíduos de Praguicidas/análise
4.
Sci Rep ; 11(1): 2255, 2021 01 26.
Artigo em Inglês | MEDLINE | ID: mdl-33500428

RESUMO

Similar to sampling perfection with application-optimized contrast using different flip angle evolutions (SPACE), T2-weighted fast field echo (FFE) also has a black blood effect and a high imaging efficiency. The purpose of this study was to optimize 3D_T2_FFE and compare it with 3D_T2_SPACE for carotid imaging. The scanning parameter of 3D_T2_FFE was optimized for the imaging of the carotid wall. Twenty healthy volunteers and 10 patients with carotid plaque underwent cervical 3D_T2_FFE and 3D_T2_SPACE examinations. The signal-to-noise ratios of the carotid wall (SNRwall) and lumen (SNRlumen), and the contrast-to-noise ratios between the wall and lumen (CNRwall_lumen) were compared. The incidence of the residual flow signal at the carotid bifurcation and the grades of flow voids in the cerebellopontine angle region in the two sequences were also compared. The reproducibility of the two sequences was tested. No significant difference was observed between the two sequences in terms of the SNRwall of healthy individuals and patients (P = 0.132 and 0.102, respectively). The SNRlumen in the 3D_T2_FFE images was lower than that in the 3D_T2_SPACE images. No significant difference was observed between the two sequences in terms of the CNRwall-lumen. The incidence of the residual flow signal at the carotid bifurcation in 3D_T2_FFE was significantly lower than that in 3D_T2_SPACE. The grades of flow suppression in the cerebellopontine angle region in 3D_T2_SPACE was lower than that in 3D_T2_FFE. Both sequences showed excellent inter-and intra-observer reproducibility. Compared to 3D_T2_SPACE, 3D_T2_FFE showed stronger flow suppression while maintaining good imaging quality, which can be used as an alternative tool for carotid imaging.

5.
Neurosurgery ; 88(3): 612-618, 2021 02 16.
Artigo em Inglês | MEDLINE | ID: mdl-33270112

RESUMO

BACKGROUND: Patients with large vessel occlusion and noncontrast computed tomography (CT) Alberta Stroke Program Early CT Score (ASPECTS) <6 may benefit from endovascular treatment (EVT). There is uncertainty about who will benefit from it. OBJECTIVE: To explore the predicting factors for good outcome in patients with ASPECTS <6 treated with EVT. METHODS: We retrospectively reviewed 60 patients with ASPECTS <6 treated with EVT in our center between March 2018 and June 2019. Patients were divided into 2 groups because of the modified Rankin Score (mRS) at 90 d: good outcome group (mRS 0-2) and poor outcome group (mRS ≥3). Baseline and procedural characteristics were collected for unilateral variate and multivariate regression analyses to explore the influent variates for good outcome. RESULTS: Good outcome (mRS 0-2) was achieved in 24 (40%) patients after EVT and mortality was 20% for 90 d. Compared with the poor outcome group, higher baseline cortical ASPECTS (c-ASPECTS), lower intracranial hemorrhage, and malignant brain edema after thrombectomy were noted in the good outcome group (all P < .01). Multivariate logistic regression showed that only baseline c-ASPECTS (≥3) was positive factor for good outcome (odds ratio = 4.29; 95% CI, 1.21-15.20; P = .024). The receiver operating characteristics curve indicated a moderate value of c-ASPECTS for predicting good outcome, with the area under receiver operating characteristics curve 0.70 (95% CI, 0.56-0.83; P = .011). CONCLUSION: Higher baseline c-ASPECTS was a predictor for good clinical outcome in patients with ASPECTS <6 treated with EVT, which could be helpful to treatment decision.


Assuntos
Procedimentos Endovasculares/tendências , Acidente Vascular Cerebral/diagnóstico por imagem , Acidente Vascular Cerebral/cirurgia , Tomografia Computadorizada por Raios X/tendências , Idoso , Idoso de 80 Anos ou mais , Procedimentos Endovasculares/métodos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Prognóstico , Estudos Retrospectivos , Trombectomia/métodos , Trombectomia/tendências , Tomografia Computadorizada por Raios X/métodos , Resultado do Tratamento
6.
BMC Genomics ; 21(1): 560, 2020 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-32799794

RESUMO

BACKGROUND: High temperatures, particularly at night, decrease rice yield and quality. As high nighttime temperatures (HNTs) become increasingly frequent due to climate change, it is imperative to develop rice crops that tolerate HNTs. DNA methylation may represent a potential avenue for HNT-tolerant rice strain development, as this mechanism regulates gene activity and cellular phenotype in response to adverse environmental conditions without changing the nucleotide sequence. RESULTS: After HNT exposure, the methylation patterns of cytosines in the CHH context differed noticeably between two coisogenic rice strains with significantly different levels in heat tolerance. Methylation differences between strains were primarily observed on successive cytosines in the promoter or downstream regions of transcription factors and transposon elements. In contrast to the heat-sensitive rice strain, the regions 358-359 bp and 2-60 bp downstream of two basal transcriptional factors (TFIID subunit 11 and mediator of RNA polymerase II transcription subunit 31, respectively) were fully demethylated in the heat-tolerant strain after HNT exposure. In the heat-tolerant strain, HNTs reversed the methylation patterns of successive cytosines in the promoter regions of various genes involved in abscisic acid (ABA)-related reactive oxygen species (ROS) equilibrium pathways, including the pentatricopeptide repeat domain gene PPR (LOC_Os07g28900) and the homeobox domain gene homeobox (LOC_Os01g19694). Indeed, PRR expression was inhibited in heat-sensitive rice strains, and the methylation rates of the cytosines in the promoter region of PRR were greater in heat-sensitive strains as compared to heat-tolerant strains. CONCLUSIONS: After HNT exposure, cytosines in the CHH context were more likely than cytosines in other contexts to be methylated differently between the heat-sensitive and heat-tolerant rice strains. Methylation in the promoter regions of the genes associated with ABA-related oxidation and ROS scavenging improved heat tolerance in rice. Our results help to clarify the molecular mechanisms underlying rice heat tolerance.


Assuntos
Oryza , Termotolerância , Citosina , Metilação de DNA , Regulação da Expressão Gênica de Plantas , Oryza/genética , Regiões Promotoras Genéticas
7.
Zhongguo Zhong Yao Za Zhi ; 45(8): 1717-1725, 2020 Apr.
Artigo em Chinês | MEDLINE | ID: mdl-32489054

RESUMO

The effects of the growing periods, processing methods, nutritive organs and cut parts of the herbs on the quality of Andrographis Herba have been studied, which could provide scientific basis for producing high-quality crude materials of Andrographis Herba. A quantitative analysis of multi-components by single-marker(QAMS) method was used to simultaneously determine 4 diterpene lactones of andrographolide(AD), neoandrographolide(NAD), 14-deoxyandrographolide(14-DAD), and dehydroandrographolide(DHAD) in 78 batches of Andrographis Herba samples. Visual analysis, clustering analysis and partial least squares discrimination analysis(PLS-DA) were used for data processing and mining. The growing periods of Andrographis Herba were divide into the rapid growing stage(Ⅰ), the luxuriant foliage stage(Ⅱ), the bud stage(Ⅲ), the flower stage(Ⅳ), the fruiting stage(Ⅴ) and the later fruiting stage(Ⅵ), six ones in total. The results showed that the total contents of 4 diterpene lactones(TC) kept almost constant in growing periods of Ⅰ-Ⅲ, began to fall off in growing period Ⅳ, decreased rapidly in growing period Ⅴ and reduced to minimum in growing period Ⅵ. Therefore, the best harvesting period for Andrographis Herba was the bud stage. For the processing methods, none significant difference occurred for TC between drying by the sun and drying in the shade. However, in comparison of the samples dried by the sun, the samples dried in the shade exhibited lower content of AD, nonetheless, the higher contents of DHAD and NAD, indicating that the process of drying in the shade may lead to the decomposition and transformation of AD. Therefore, when the weather conditions permitted, the method drying by the sun should be used. The distributions of AD, DHAD and TC in the different cut parts and nutritive organs were determined as follows: upper cut parts > middle cut parts ≈ entire herbs > lower cut parts, leaves > entire herbs > stems. Furthermore, the contents of 4 diterpene lactones in leaves and herbs were much higher than those in stems. Therefore, it was suggested that the upper and middle cut parts of the herbs or the parts containing leaves should be preferred for harvesting to ensure the proportion of the leaves in Andrographis Herba.


Assuntos
Andrographis , Diterpenos , Lactonas , Folhas de Planta
8.
Zhongguo Zhong Yao Za Zhi ; 45(9): 2091-2102, 2020 May.
Artigo em Chinês | MEDLINE | ID: mdl-32495558

RESUMO

Taking Lonicerae Japonicae Flos as an example, the method of "expert consensus of different regions" was used to screen the representative samples and evaluate their commodity grades. The correlation analysis, hierarchical cluster analysis and partial least squares discriminant analysis(PLS-DA) of "commodity grade-appearance characteristic-component content" were carried out to reveal the scientificity of traditional commodity grade of Chinese medicinal material. By referring to the existing literature and the grade investigation from the sample collection regions, 78 "initial grade" samples were screened out from 118 collected samples. Authoritative experts from four regions(n=4) including Linyi(Shangdong province), Bozhou(Anhui province), Anguo(Hebei province) and Beijing were organized to evaluate their commodity grades, separately. Based on the grade consistency rate(R_i≥70%), 69 "local grade" samples were screened out from the "initial grade" samples. Based on the average grade consistency rate ■ "authoritative grade" samples were screened out from the "local grade" samples, including15 first-grade samples, 9 second-grade samples, 11 third-grade samples and 17 fourth-grade samples. For these "authoritative grade" samples, the main appea-rance characteristics were quantified and the contents of 13 components were determined by ultra performance liquid chromatography(UPLC). Furthermore, the total contents of 6 phenolic acids, 4 flavonoids and 3 iridoids were calculated, respectively. The results of correlation analysis showed that 4 appearance characteristics indices were correlated with the commodity grades: color, rate of yellow bars(including blooming flowers), rate of black heads(including black bars), and rate of stems and leaves(including bud debris). Five component content indices were correlated with the commodity grades: chlorogenic acid, isochlorogenic acid C, sweroside, loganin and the total contents of six phenolic acids. Furthermore, chlorogenic acid, loganin and the total contents of six phenolic acids showed significantly negative correlation with the main appearance characteristics, indicating that the appearance characteristics of Lonicerae Japonicae Flos can reflect its internal quality, and these 3 indices can be used as quality markers(Q-markers). The results of hierarchical cluster analysis showed that the samples of four grades were classified into four categories, and the samples with the same grades and the same categories accounted for 80.8% of the total samples, while the samples with the different grades were obviously classified into different categories. The results of PLS-DA analysis showed that the samples of different grades showed obvious intragroup aggregation and intergroup dispersion. The above results indicated that it was feasible to evaluate the traditional commodity grade of Lonicerae Japonicae Flos by the method of "expert consensus of different regions". For the evaluation of traditional commodity grade of Chinese medicinal material, the samples should be representative, expert conclusions should have enough consensuses, and grade determination should be authoritative. As the crystallization of clinical experience, traditional commodity grade can scientifically reflect the internal quality of Chinese medicinal material.


Assuntos
Medicamentos de Ervas Chinesas , Lonicera , Cromatografia Líquida de Alta Pressão , Flores , Controle de Qualidade
9.
Neuroradiology ; 62(7): 867-876, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32242265

RESUMO

PURPOSE: Data on posterior circulation tandem occlusions in acute ischemic stroke are scarce: recognition may be challenging and little is known about optimal treatment strategy. We report our endovascular treatment strategy for posterior circulation tandem occlusion. METHODS: Consecutive patients with posterior circulation tandem occlusions in our centre were enrolled retrospectively. The preferred strategy was "distal-to-proximal" strategy, which means opening the distal occlusion first followed by treatment of the proximal pathology. The imaging characteristics, treatment strategy, clinical outcomes, and complications of patients with posterior circulation tandem occlusions were analyzed. RESULTS: In total, 21 patients with posterior circulation tandem occlusions were enrolled in the study, which accounted for 23.6% of patients with posterior circulation stroke in our centre. The mean age was 60 years (range 32 to 80), and median pre-procedure NIHSS score was 28 (interquartile range: 13-31). Eighteen patients (85.7%) had vertebrobasilar artery tandem occlusions and 3 (14.3%) had basilar artery to basilar artery tandem occlusions. All distal occlusions were successfully recanalized (modified TICI 2b/3). Two (9.5%) of the proximal lesions were not treated. A total of 57.1% of the patients had stents implanted on the proximal occlusions. The rate of mRS 0-3 at 3 months was 57.1% and the mortality rate was 19.0%. CONCLUSION: In patients with acute ischaemic stroke caused by posterior circulation tandem occlusions, we favor "distal-to-proximal" strategy based on the positive results in this small series. Nevertheless, a more extensive study is required to explore the optimal treatment strategy further.


Assuntos
Procedimentos Endovasculares , AVC Isquêmico/diagnóstico por imagem , AVC Isquêmico/cirurgia , Neuroimagem/métodos , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos
10.
Neurosci Lett ; 711: 134412, 2019 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-31381959

RESUMO

Erythropoietin (EPO) has an exact neuroprotective effect on stroke. However, it remains unknown whether it participates in axonal sprouting after neuron damage. Growth and differentiation factor 10 (GDF10) has been shown to be a trigger of axonal sprouting after stroke. Hence, it was hypothesized that EPO promotes axonal sprouting mainly through GDF10. In the present in vitro experiment, it was found that EPO could promote axonal sprouting and GDF10 expression in a dose-dependent manner. The knockdown of GDF10 using siRNA abolished the effect of EPO-mediated axonal sprouting, indicating that GDF10 is the executor of EPO-mediated axonal sprouting. The treatment of neurons with nuclear factor-kappaB (NF-κB) inhibitor JSH-23 could inhibit the accumulation of NF-κB phospho-p65 (p-p65) in the nucleus, the upregualtion of GDF10 and extending of axonal length. Furthermore, the addition of Janus kinase 2 (JAK2) inhibitor CEP-33779 or phosphoinositide 3-kinase (PI3K) inhibitor LY294002 to the culture medium also blocked the nuclear translocation of p-p65, the expression of GDF10, and axonal sprouting, suggesting that EPO induces axonal sprouting via activating cellular JAK2 and PI3K signaling. Impeding JAK2 signaling with CEP-33779 can suppress the phosphorylation of PI3K, and this confirms that the upstream of PI3K signaling is JAK2. These present results provide a novel insight into the role of EPO and the molecular mechanism of axonal sprouting, which is beneficial for the development of novel approaches for neurological recovery after brain injury, including stroke.


Assuntos
Axônios/metabolismo , Eritropoetina/metabolismo , Fator 10 de Diferenciação de Crescimento/metabolismo , Regeneração Nervosa/fisiologia , Neurogênese/fisiologia , Animais , Camundongos , Transdução de Sinais/fisiologia , Regulação para Cima
11.
Zhongguo Zhong Yao Za Zhi ; 44(10): 2078-2083, 2019 May.
Artigo em Chinês | MEDLINE | ID: mdl-31355564

RESUMO

The traditional Chinese medicine standard decoction is prepared on the basis of the theory of traditional Chinese medicine and clinical application. With reference to the modern extraction method,the single decoction of traditional Chinese medicine is prepared by the standardized process,and the establishment of its quality standards is conducive to standardizing clinical medication. This research is to set an evaluation standard for the quality of salt-processed Psoraleae Fructus standard decoction. Twelve batches of salt-processed Psoraleae Fructus standard decoctions were prepared. The contents of psoralen and isopsoralen were determined,the transfer and extract rates were calculated,and the pH value was measured; HPLC fingerprint method was established for analysis. The results of the 12 batches of samples revealed that the transfer rates of psoralen and isopsoralen were 17. 10%-26. 40%,14. 70%-22. 70%,respectively; the extract rate was between 14. 7%-27. 0%,and the pH value was between 5. 4-6. 9. Moreover,7 common chromatographic peaks were determined based on fingerprint by using similarity evaluation system for chromatographic fingerprint of traditional Chinese medicine( 2012 A).The similarities of the 12 batches of samples were analyzed and compared,and the results showed that the similarities were all higher than0. 9. In this study,the preparation method for salt-processed Psoraleae Fructus decoction was standard,with high similarities in fingerprint. This study build a convenient and reliable method of comprehensive quality evaluation,with a high precision,stability and repeatability,which can provide a reference for the quality control of salt-processed Psoraleae Fructus dispensing granules.


Assuntos
Medicamentos de Ervas Chinesas/análise , Frutas/química , Psoralea/química , Controle de Qualidade , Cromatografia Líquida de Alta Pressão , Medicina Tradicional Chinesa , Compostos Fitoquímicos/análise
12.
World Neurosurg ; 130: e444-e448, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31252077

RESUMO

INTRODUCTION: Analysis of safety and effectiveness of stent angioplasty for failure of thrombectomy in patients with acute intracranial atherosclerotic occlusion. METHODS: Retrospective continuous analysis of the clinical data of 458 patients with acute stroke undergoing endovascular artery thrombectomy in Changhai Hospital of Second Military Medical University from May 2013 to February 2018. Patients with acute intracranial atherosclerotic occlusion treating with stent implantation were included and the safety and effectiveness of stent angioplasty was evaluated. RESULTS: There was successful stent release in 55 patients. There were 36 cases (65.5%) with occlusion located in the anterior circulation and 19 cases (34.5%) in the posterior circulation. Twenty patients underwent intravenous thrombolysis before surgery, and the time of admission to intravenous thrombolysis was (39.9 ± 13.2) minutes. Fifty-four patients (98.2%) achieved modified thrombolysis in cerebral infarction 2b-3 recanalization. The National Institutes of Health Stroke Scale score 2.0 (0.0,6.0) 7 days after surgery was significantly improved compared with the preoperative National Institutes of Health Stroke Scale score 12.5 (6.0-20.0) (Z = -4.073, P < 0.05). Intracranial hemorrhage occurred in 7 patients (12.7%) after surgery, among them, symptomatic intracranial hemorrhage occurred in 2 cases (3.6%). CTP examination of the skull 3-5 days after operation showed: Among 39 cases (70.9%): 33 cases (84.6%) were patency, 4 cases (10.3%) were occlusion, 2 cases (5.1%) were moderate stenosis, and 16 cases (29.1%) were not examined by computed tomography perfusion. Ninety-day follow-up showed that a total of 43 cases were followed up, and 12 cases were lost to follow-up. Thirty-four patients (79.1%) had a good prognosis 90 days after surgery (modified Rankin scale score 0-2) and 9 patients died (20.9%). CONCLUSION: When thrombectomy in patients with acute intracranial atherosclerotic occlusion fails, stent angioplasty is safe and effective; however, short-term stent reocclusion after surgery cannot be ignored. Because of the small sample size, larger multicenter clinical studies are needed to confirm this result.


Assuntos
Angioplastia/métodos , Arteriosclerose Intracraniana/cirurgia , Reoperação , Trombectomia , Adulto , Idoso , Idoso de 80 Anos ou mais , Angioplastia/efeitos adversos , Angioplastia/instrumentação , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Stents , Resultado do Tratamento
13.
Zhongguo Zhong Yao Za Zhi ; 44(4): 730-739, 2019 Feb.
Artigo em Chinês | MEDLINE | ID: mdl-30989886

RESUMO

To solve the problems of the poor resolution of chromatographic separation,the weak durability of the relative correction factors,and the low accuracy of content determination results in the quantitative analysis of multi-components by single-marker( QAMS) method with andrographolide as the internal reference substance in the existing research of Andrographis Herba,a new QAMS method using dehydroandrographolide as the internal reference substance was established for the first time in this study. This new method can be used to simultaneously determine four diterpene lactones,including andrographolide( A),neoandrographolide( B),14-deoxyandrographolide( C),and dehydroandrographolide( S) through the optimization of chromatographic conditions and systematic investigation of methodology. At the present HPLC chromatographic conditions,four components could be well separated( R > 1. 5),and the methodology validations could satisfy the requirement of quantitative analysis. The relative correction factors( RCFs) of fA/S,fB/S,fC/S were determined as 0. 65,0. 54,0. 78,respectively. The relative standard deviations( RSDs) of their RCFs ranged between 1. 3%-5. 1%,0. 25%-0. 33%,0. 070%-0. 15%,0. 070%-0. 22%,respectively with three brands of HPLC instruments,five brands of C18 column,different flow rates( 0. 9,1. 0,1. 1 m L·min~(-1)),and different column temperatures( 25,30,35 ℃),indicating good durability of the RCFs. The relative retention value( RRV) method was used to locate the chromatographic peak of the components to be determined.The RRVs of rA/S,rB/S,and rC/Swere 0. 44,0. 86,0. 97,respectively. The RSDs of the RRVs ranged between 0. 030%-1. 6% with different HPLC instruments and columns,showing accurate peak location. The present QAMS method and the external standard method( ESM)were both used to determine the contents of four diterpene lactones from Andrographis Herba( 6 batches of medicinal materials and 18 batches of cut crude drugs). The relative errors of the determined content results between two methods were less than 2. 0%. It demonstrated that there was no significant difference in content results between these two methods,indicating good accuracy of the present QAMS method. Therefore,in this study,an accurate and highly durable QAMS method using dehydroandrographolide as the internal reference substance was established for simultaneous determination of four diterpene lactones. This method could be used to effectively control the quality of Andrographis Herba and provide technical basis for the formulation of traditional Chinese medicine industry standard and improvement of the Chinese Pharmacopoeia standard of Andrographis Herba.


Assuntos
Andrographis , Medicamentos de Ervas Chinesas , Cromatografia Líquida de Alta Pressão , Diterpenos , Controle de Qualidade
14.
J Virol ; 93(1)2019 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-30333168

RESUMO

Type I interferon (IFN) inhibits viruses by inducing the expression of antiviral proteins. The IFN-induced myxovirus resistance B (MxB) protein has been reported to inhibit a limited number of viruses, including HIV-1 and herpesviruses, but its antiviral coverage remains to be explored further. Here we show that MxB interferes with RNA replication of hepatitis C virus (HCV) and significantly inhibits viral replication in a cyclophilin A (CypA)-dependent manner. Our data further show that MxB interacts with the HCV protein NS5A, thereby impairing NS5A interaction with CypA and NS5A localization to the endoplasmic reticulum, two events essential for HCV RNA replication. Interestingly, we found that MxB significantly inhibits two additional CypA-dependent viruses of the Flaviviridae family, namely, Japanese encephalitis virus and dengue virus, suggesting a potential link between virus dependence on CypA and virus susceptibility to MxB inhibition. Collectively, these data have identified MxB as a key factor behind IFN-mediated suppression of HCV infection, and they suggest that other CypA-dependent viruses may also be subjected to MxB restriction.IMPORTANCE Viruses of the Flaviviridae family cause major illness and death around the world and thus pose a great threat to human health. Here we show that IFN-inducible MxB restricts several members of the Flaviviridae, including HCV, Japanese encephalitis virus, and dengue virus. This finding not only suggests an active role of MxB in combating these major pathogenic human viruses but also significantly expands the antiviral spectrum of MxB. Our study further strengthens the link between virus dependence on CypA and susceptibility to MxB restriction and also suggests that MxB may employ a common mechanism to inhibit different viruses. Elucidating the antiviral functions of MxB advances our understanding of IFN-mediated host antiviral defense and may open new avenues to the development of novel antiviral therapeutics.


Assuntos
Ciclofilina A/farmacologia , Hepacivirus/fisiologia , Interferons/farmacologia , Proteínas de Resistência a Myxovirus/metabolismo , Proteínas não Estruturais Virais/metabolismo , Replicação Viral/efeitos dos fármacos , Animais , Linhagem Celular , Chlorocebus aethiops , Ciclosporina/farmacologia , Retículo Endoplasmático/metabolismo , Técnicas de Silenciamento de Genes , Células HEK293 , Hepacivirus/efeitos dos fármacos , Humanos , Proteínas de Resistência a Myxovirus/genética , Ligação Proteica/efeitos dos fármacos , Células Vero
15.
PLoS Pathog ; 13(9): e1006625, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28938017

RESUMO

Enterovirus 71 (EV71) is the major causative agent of hand, foot and mouth disease (HFMD) in children, causing severe clinical outcomes and even death. Here, we report an important role of the highly conserved alanine residue at position 107 in the capsid protein VP1 (VP1A107) in the efficient replication of EV71. Substitutional mutations of VP1A107 significantly diminish viral growth kinetics without significant effect on viral entry, expression of viral genes and viral production. The results of mechanistic studies reveal that VP1A107 regulates the efficient cleavage of the VP0 precursor during EV71 assembly, which is required, in the next round of infection, for the transformation of the mature virion (160S) into an intermediate or A-particle (135S), a key step of virus uncoating. Furthermore, the results of molecular dynamic simulations and hydrogen-bond networks analysis of VP1A107 suggest that flexibility of the VP1 BC loop or the region surrounding the VP1107 residue directly correlates with viral infectivity. It is possible that sufficient flexibility of the region surrounding the VP1107 residue favors VP0 conformational change that is required for the efficient cleavage of VP0 as well as subsequent viral uncoating and viral replication. Taken together, our data reveal the structural role of the highly conserved VP1A107 in regulating EV71 maturation. Characterization of this novel determinant of EV71 virulence would promote the study on pathogenesis of Enteroviruses.


Assuntos
Enterovirus Humano A/fisiologia , Infecções por Enterovirus/virologia , Células Vero/virologia , Replicação Viral/genética , Aminoácidos/genética , Animais , Proteínas do Capsídeo/metabolismo , Chlorocebus aethiops , Mutação de Sentido Incorreto/genética , Internalização do Vírus
16.
PLoS One ; 12(4): e0175789, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28426775

RESUMO

The transmission of infectious diseases has been studied by mathematical methods since 1760s, among which SIR model shows its advantage in its epidemiological description of spread mechanisms. Here we established a modified SIR model with nonlinear incidence and recovery rates, to understand the influence by any government intervention and hospitalization condition variation in the spread of diseases. By analyzing the existence and stability of the equilibria, we found that the basic reproduction number [Formula: see text] is not a threshold parameter, and our model undergoes backward bifurcation when there is limited number of hospital beds. When the saturated coefficient a is set to zero, it is discovered that the model undergoes the Saddle-Node bifurcation, Hopf bifurcation, and Bogdanov-Takens bifurcation of codimension 2. The bifurcation diagram can further be drawn near the cusp type of the Bogdanov-Takens bifurcation of codimension 3 by numerical simulation. We also found a critical value of the hospital beds bc at [Formula: see text] and sufficiently small a, which suggests that the disease can be eliminated at the hospitals where the number of beds is larger than bc. The same dynamic behaviors exist even when a ≠ 0. Therefore, it can be concluded that a sufficient number of the beds is critical to control the epidemic.


Assuntos
Doenças Transmissíveis/epidemiologia , Modelos Teóricos , Humanos , Incidência
17.
Exp Neurol ; 277: 139-149, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26724216

RESUMO

Polysialic acid (PSA), a carbohydrate polymer associated with the neural cell adhesion molecule (NCAM), plays an important role in the migration, differentiation and maturation of neuroblasts. Endoneuraminidase-N (Endo-N) can specifically cleave PSA from NCAM. The objective of the present study was to examine: the effect of Endo-N on characteristics of subventricular zone (SVZ)-derived neural progenitor cells (NPCs) in vitro; whether intraventricular administration of Endo-N could increase ectopic migration of SVZ-derived NPCs into 6-hydroxydopamine (6-OHDA)-lesioned striatum, and whether migrated NPCs could differentiate into neuronal and glial cells. In in vitro study, Endo-N was found to inhibit the migration of NPCs, and to enhance the differentiation of NPCs. In in vivo study, mice sequentially received injections of 6-OHDA into the right striatum, Endo-N into the right lateral ventricle, and bromodeoxyuridine (BrdU) intraperitoneally. The data showed that intraventricular injections of Endo-N disorganized the normal structure of the rostral migratory stream (RMS), and drastically increased the number of BrdU-immunoreactive (IR) cells in 6-OHDA-lesioned striatum. In addition, a number of BrdU-IR cells were double labeled for doublecortin (DCX), NeuN or glial fibrillary acidic protein (GFAP). The results suggest that interruption of neuroblast chain pathway with Endo-N facilitates ectopic migration of SVZ-derived NPCs into the lesioned striatum, and migrated NPCs can differentiate into neurons and astrocytes.


Assuntos
Infarto Encefálico/patologia , Movimento Celular/efeitos dos fármacos , Corpo Estriado/patologia , Glicosídeo Hidrolases/farmacologia , Ventrículos Laterais/citologia , Células-Tronco Neurais/efeitos dos fármacos , Animais , Animais Recém-Nascidos , Infarto Encefálico/induzido quimicamente , Ciclo Celular/efeitos dos fármacos , Diferenciação Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Proteína Glial Fibrilar Ácida/metabolismo , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Camundongos , Camundongos Endogâmicos C57BL , Molécula L1 de Adesão de Célula Nervosa/metabolismo , Oxidopamina/toxicidade , Ácidos Siálicos/metabolismo , Fatores de Tempo , Tubulina (Proteína)/metabolismo
18.
Zhongguo Zhong Yao Za Zhi ; 41(14): 2660-2668, 2016 Jul.
Artigo em Chinês | MEDLINE | ID: mdl-28905603

RESUMO

This paper aims to investigate the correlation between the antioxidant activity of Prunella vulgaris and its total phenolic acids content by measuring the antioxidant activity of different sources and different organs of P. vulgaris and the total contents of protocatechuic acid, protocatechuic aldehyde, caffeic acid, salviaflaside and rosmarinic acid in these samples. Using the 50% methanol extract of P. vulgaris samples as the research object, DPPH method and HPLC method were used respectively to determine the antioxidant activities and the total contents of the above-mentioned five analytes in P. vulgaris samples. 0.5 mL of 50% methanol extract of P. vulgaris reacts with 0.1 mmol•L⁻¹ DPPH ethanol solution for 60 min, then the absorbance of the reaction solution was measured at 517 nm, scavenging rate and IC50 values were calculated by the absorbance and the sample concentration for evaluating the antioxidant activity. HPLC analysis was made on a C18 Epic column, with acetonitrile-0.1% formic acid aqueous solution as mobile phase (gradient elution), and the detection wavelength was set at 280 nm. The correlation between the antioxidant capacity of different habitats and different organs of P. vulgaris and the total contents of five kinds of phenolic acids was analyzed by partial least squares method. The reaction dose-response range of 50% methanol extract of P. vulgaris with 0.1 mmol•L⁻¹ DPPH ethanol solution was 0.300-1.65 g•L⁻¹. When the quantities of potocatechuic acid, protocatechuic aldehyde, caffeic acid, salviaflaside and rosmarinic acid were respectively in 0.007 84-0.980, 0.011 5-1.44, 0.008 64-1.08, 0.080 0-1.00 and 0.079 8-0.998 µg range, their quantities were in good linear relationship with the corresponding peak areas. The average recovery of 5 components were 97.76%, 96.88%, 100.3%, 102.1%, 104.5%, with RSD of 1.8%, 1.6%, 1.7%, 1.6% and 1.7%, respectively. In a certain range of crude drug quantity, the antioxidant activity of each organ of P. vulgaris and total phenolic acids content inside has a good linear correlation. Therefore, in certain quality range of crude drug, DPPH bioassay combined with HPLC content determination can be used for the quality control of P. vulgaris, as is a new method for the quality control of P. vulgaris.


Assuntos
Antioxidantes/análise , Medicamentos de Ervas Chinesas/normas , Hidroxibenzoatos/análise , Prunella/química , Bioensaio , Cromatografia Líquida de Alta Pressão , Extratos Vegetais
19.
Zhongguo Zhong Yao Za Zhi ; 41(15): 2843-2854, 2016 Aug.
Artigo em Chinês | MEDLINE | ID: mdl-28914027

RESUMO

Through a series of methodology investigations, we established a new method for simultaneous analysis of epimedins A, B, C, icariin and baohuoside I in Epimedii Folium by using high performance liquid chromatography (HPLC). Meanwhile, using Icariin as an internal reference substance to establish the relative correct factors and relative retention values of Epimedins A, B, C and Baohuoside I to Icariin, then using the quantitative analysis of multi-components by single-marker (QAMS) model, the five analytes can be quantitatively determined in Epimedii Folium and its processed products as well as Kanggu Zengsheng capsule only by measuring the content of icariin in the corresponding samples. All these analysis are completed in the same chromatorgraphic conditions. This paper played the part of demonstration role in the popularization and application of QAMS method established in a single herb to the proprietary Chinese medicines containing this herb.


Assuntos
Medicamentos de Ervas Chinesas/química , Epimedium/química , Flavonoides/química , Cromatografia Líquida de Alta Pressão , Compostos Fitoquímicos/química
20.
Zhongguo Zhong Yao Za Zhi ; 41(18): 3389-3399, 2016 Sep.
Artigo em Chinês | MEDLINE | ID: mdl-28925122

RESUMO

Using reversed-phase high performance liquid chromatography, nine ginsenosides were simultaneously separated on an UltimateC18 column with high-resolution and high purity of each chromatographic peak. Adopting the QAMS quality evaluation model for traditional Chinese medicines, ginsenoside Rb1 was used as the internal reference substance, and the relative correction factors (RCFs) and the relative retention values (RTRs) of ginsenosides Rg1, Re, Rf, Rb1, Rc, Rb2, Rb3, Rd and 20 (S)-ginsenoside Rg3 to ginsenoside Rb1 were calculated individually. Through a series of methodology evaluations, and positioned by the red ginseng reference chromatograph and RTVs, nine ginsenosides in red ginseng were simultaneously assayed only by quantitative determined ginsenoside Rb1.


Assuntos
Ginsenosídeos/análise , Panax/química , Cromatografia Líquida de Alta Pressão , Reprodutibilidade dos Testes
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...