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1.
World J Stem Cells ; 16(2): 137-150, 2024 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-38455095

RESUMO

Blood vessels constitute a closed pipe system distributed throughout the body, transporting blood from the heart to other organs and delivering metabolic waste products back to the lungs and kidneys. Changes in blood vessels are related to many disorders like stroke, myocardial infarction, aneurysm, and diabetes, which are important causes of death worldwide. Translational research for new approaches to disease modeling and effective treatment is needed due to the huge socio-economic burden on healthcare systems. Although mice or rats have been widely used, applying data from animal studies to human-specific vascular physiology and pathology is difficult. The rise of induced pluripotent stem cells (iPSCs) provides a reliable in vitro resource for disease modeling, regenerative medicine, and drug discovery because they carry all human genetic information and have the ability to directionally differentiate into any type of human cells. This review summarizes the latest progress from the establishment of iPSCs, the strategies for differentiating iPSCs into vascular cells, and the in vivo transplantation of these vascular derivatives. It also introduces the application of these technologies in disease modeling, drug screening, and regenerative medicine. Additionally, the application of high-tech tools, such as omics analysis and high-throughput sequencing, in this field is reviewed.

3.
BMJ Open ; 12(1): e057929, 2022 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-35078854

RESUMO

OBJECTIVE: To evaluate the general population's awareness of and attitudes toward Helicobacter pylori (HP) screening and health behaviours. DESIGN: Cross-sectional study. SETTING: Hengyang, Hunan Province, China. PARTICIPANTS: Using stratified cluster random sampling, a pretested structured questionnaire was used to interview members of the general population aged ≥18 years. PRIMARY AND SECONDARY OUTCOME MEASURES: Knowledge of and attitudes toward HP screening and associated health behaviours, sociodemographic factors associated with HP knowledge, and screening behaviours. RESULTS: This study featured 1042 participants. The average knowledge score was 11 (QL=4, QU=20, range 0-29). Approximately 68.9% of the participants said they had heard of HP, but 67.5% had never had an HP test. The most common reasons for not undergoing screening were 'no symptoms' (55.7%) and 'lack of knowledge regarding the benefits of the test' (21.1%). Independent factors related to knowledge included age, education level, occupation, HP infection, frequency of drinking unboiled water (p<0.05). Factors independently associated with screening behaviour included occupation, average monthly income, presence/absence of indigestion, stomach discomfort or pain, and/or stomach disease and knowledge score (p<0.05). Overall, 941 (90.3%) participants never used anti-HP toothpaste, and 442 (40.5%) never used serving spoons or chopsticks. The risk factors for HP infection included eating out and eating in groups (p<0.05). CONCLUSION: In China, the general population has poor knowledge of HP, but most people have a positive attitude towards HP screening. Being asymptomatic and lacking knowledge about testing were the main reasons for reluctance to be screened. These results highlight the urgent need for educational activities to raise awareness, enhance screening rates for HP, and encourage people to adopt a healthy lifestyle.


Assuntos
Infecções por Helicobacter , Helicobacter pylori , Adolescente , Adulto , China/epidemiologia , Estudos Transversais , Comportamentos Relacionados com a Saúde , Conhecimentos, Atitudes e Prática em Saúde , Infecções por Helicobacter/diagnóstico , Infecções por Helicobacter/epidemiologia , Humanos , Inquéritos e Questionários
4.
BMJ Open ; 11(7): e045168, 2021 07 12.
Artigo em Inglês | MEDLINE | ID: mdl-34253663

RESUMO

OBJECTIVE: To assess the awareness, attitude and barriers of colorectal cancer screening among high-risk populations in China. DESIGN: A cross-sectional study was employed. SETTING: This study was conducted in nine hospitals in Hunan province, China. PARTICIPANTS: Individuals with a high-risk for colorectal cancer were interviewed using a pretested structured questionnaire. PRIMARY AND SECONDARY OUTCOME MEASURES: Knowledge, attitude towards colorectal cancer screening, sociodemographic factors associated with screening knowledge and behaviour and barriers of colorectal cancer screening. RESULTS: This study included 684 participants. The mean knowledge score was 11.86/24 (SD 4.84). But over 70% of them held a positive attitude towards screening. Only 13.3% had undergone colorectal cancer screening. Independent factors related to knowledge were education level of college or above, working as a white collar, higher income, having health insurance, having seen a doctor in the past year and with a high perceived risk (p<0.05). Factors independently associated with screening behaviour included personal history of colorectal disease, having seen a doctor in the past year, previous discussion of colorectal cancer screening, high perceived risk and better knowledge (p<0.05). Main reasons for not undergoing screening were no symptoms or discomfort (71.1%), never having thought of the disease or screening (67.4%) and no doctor advised me (29.8%). CONCLUSION: In China, the majority of high-risk people had deficient knowledge and had never undergone colorectal cancer screening. But most of them held a positive attitude towards the benefits of colorectal cancer screening. This has promising implications to design targeted educational campaigns and establish screening programmes to improve colorectal cancer awareness and screening participation. Healthcare professionals should advise high-risk individuals to participate in screening and inform them about cancer risk.


Assuntos
Neoplasias Colorretais , Detecção Precoce de Câncer , China , Neoplasias Colorretais/diagnóstico , Estudos Transversais , Conhecimentos, Atitudes e Prática em Saúde , Humanos , Programas de Rastreamento , Fatores de Risco , Inquéritos e Questionários
6.
Infect Dis Ther ; 10(1): 241-252, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33111216

RESUMO

INTRODUCTION: This study aimed to analyze the diversity of intestinal flora in patients with chronic hepatitis B (CHB) and investigate the effect of entecavir on the intestinal flora in these patients. METHODS: Thirty patients with CHB and 30 healthy controls were recruited from the Department of Infectious Diseases and Department of Gastroenterology of Shanghai Tongji Hospital between January 2017 and December 2018. Stool samples were collected for the detection of intestinal flora by high-throughput sequencing. Patients with CHB received antivirus therapy with entecavir for 8 weeks. The biochemical and virological responses were assessed and the intestinal flora were compared. RESULTS: After entecavir treatment, the blood levels of alanine aminotransferase (ALT), interleukin-6 (IL-6), IL-8, tumor necrosis factor (TNF), and hepatitis B virus (HBV) DNA reduced significantly in patients with CHB and the species abundance of intestinal flora increased markedly. In patients with CHB, the unique genera included Butyrivibrio, Phaseolus acutifolius, and Prevotellaceae NK3B31 group before treatment and Howardella, Candidatus Stoquefichus, Citrobacter, Dysgonomonas, Faecalicoccus, Methanobrevibacter, Mitsuokella, Mobilitalea, Succinivibrio, Gluconobacter, and Plesiomonas after treatment. The abundance of the following genera increased significantly after entecavir treatment in patients with CHB: Clostridium sensu stricto 1, Erysipelotrichaceae UCG-007, and Intestinibacter. The abundance of Streptococcus, Atopobium, and Murdochiella reduced markedly after entecavir treatment in patients with CHB. CONCLUSION: After 8-week entecavir treatment, the blood biochemical, immunological, and virological responses improved significantly, the species abundance of intestinal flora increased markedly, and there were unique genera in patients with CHB before and after treatment.

7.
BMJ Open ; 9(7): e029638, 2019 07 23.
Artigo em Inglês | MEDLINE | ID: mdl-31340970

RESUMO

OBJECTIVES: This study aimed to assess the knowledge of risk factors and warning symptoms and attitude towards gastric cancer screening among the general population in China. SETTING: Hunan province, China PARTICIPANTS: Individuals aged older than 18 years were recruited using a cluster sampling method. DESIGN: A cross-sectional study, and a pretested structured questionnaire was used to assess participants' awareness of gastric cancer. PRIMARY AND SECONDARY OUTCOME MEASURES: Knowledge level of risk factors and warning symptoms of gastric cancer, gastric cancer screening attitude, sociodemographic factors associated with gastric cancer knowledge and screening behaviour. RESULTS: This study comprised 1200 participants with a mean age of 40.31 (SD 16.73) years, of whom 622 (51.8%) were women. The mean score for gastric cancer knowledge was 8.85/22 (SD 6.48). There were 47.0% of the participants who had a low knowledge level about the risk factors and warning symptoms of gastric cancer. In total, 83.8% believed screening is helpful for early detection of gastric cancer, and 15.2% had undergone gastric cancer screening. The most common reason for not undergoing screening was having 'no symptoms' (63.0%), followed by 'fear of undergoing gastroscopy' (38.1%). Independent factors related to lower knowledge levels included male sex, living in rural areas, lower educational level, working as a farmer and without a family history of gastric cancer (p<0.05). Factors independently associated with screening behaviour included white-collar employment, higher income and having upper gastrointestinal tract diseases (p<0.05). CONCLUSIONS: In China, people have poor knowledge about risk factors and warning symptoms of gastric cancer, but a majority have a positive attitude towards the benefits of gastric cancer screening. Being asymptomatic and having a fear of gastroscopy were the main self-reported reasons for not undergoing screening. These results highlight the urgent need for educational campaigns to improve gastric cancer awareness.


Assuntos
Detecção Precoce de Câncer/psicologia , Conhecimentos, Atitudes e Prática em Saúde , Neoplasias Gástricas/diagnóstico , Adulto , China , Estudos Transversais , Feminino , Humanos , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Fatores de Risco , Inquéritos e Questionários
8.
Zhongguo Zhong Yao Za Zhi ; 42(14): 2676-2682, 2017 Jul.
Artigo em Chinês | MEDLINE | ID: mdl-29098821

RESUMO

The aim of this paper is to investigate the topical pharmacodynamics behavior of different lipophilic model drugs after treatment with essential oil from Zanthoxyli Pericarpium by using the cutaneous microdialysis technique, and then evaluate its in vivo transdermal penetration enhancing properties. Two traditional Chinese medicine active components, namely tetramethylpyrazine and puerarin, were chosen as lipophilic and hydrophilic model drugs, respectively. Firstly, the concentration difference method was employed to measure the in vitro recovery rate and loss of the microdialysis probe, and the in vivo recoveries of two model drugs were determined by using the retrodialysis method. Secondly, the skin pharmacodynamics behaviors of two model drugs were studied after treatment with different concentrations of the essential oil, and the well-established and standard penetration enhancer Azone was selected as a positive control. It was found that the recovery of microdialysis probe was equal to its loss for two model drugs, with no interaction between drugs in dialysis membranes. The retrodialysis studies revealed that the in vivo recovery of tetramethylpyrazine and puerarin were 59.17%, 19.85%, respectively. The skin pharmacodynamics studies showed that the essential oil could facilitate the transdermal absorption of tetramethylpyrazine in a concentration-dependent manner, and the enhancement ratio (ER) for 5% essential oil was 98.64, which was higher than that of the optimum concentration of Azone (3% Azone, ER=89.11). Meanwhile, the Zanthoxyli Pericarpium could effectively promote the transdermal permeation of the puerarin in a concentration-dependent manner. Hence, this study further confirmed that the Zanthoxyli Pericarpium had excellent penetration-enhancing activity as a natural transdermal penetration enhancer, providing data support for its application in traditional Chinese medicine external preparations.


Assuntos
Medicamentos de Ervas Chinesas/administração & dosagem , Óleos Voláteis/administração & dosagem , Óleos de Plantas/administração & dosagem , Absorção Cutânea , Zanthoxylum/química , Administração Cutânea , Microdiálise , Pele
9.
Chin Med J (Engl) ; 128(13): 1820-5, 2015 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-26112726

RESUMO

OBJECTIVE: Mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS) is a progressive, multisystem affected mitochondrial disease associated with a number of disease-related defective genes. MELAS has unpredictable presentations and clinical course, and it can be commonly misdiagnosed as encephalitis, cerebral infarction, or brain neoplasms. This review aimed to update the diagnosis progress in MELAS, which may provide better understanding of the disease nature and help make the right diagnosis as well. DATA SOURCES: The data used in this review came from published peer review articles from October 1984 to October 2014, which were obtained from PubMed. The search term is "MELAS". STUDY SELECTION: Information selected from those reported studies is mainly based on the progress on clinical features, blood biochemistry, neuroimaging, muscle biopsy, and genetics in diagnosing MELAS. RESULTS: MELAS has a wide heterogeneity in genetics and clinical manifestations. The relationship between mutations and phenotypes remains unclear. Advanced serial functional magnetic resonance imaging (MRI) can provide directional information on this disease. Muscle biopsy has meaningful value in diagnosing MELAS, which shows the presence of ragged red fibers and mosaic appearance of cytochrome oxidase negative fibers. Genetic studies have reported that approximately 80% of MELAS cases are caused by the mutation m.3243A>G of the mitochondrial transfer RNA (Leu (UUR)) gene (MT-TL1). CONCLUSIONS: MELAS involves multiple systems with variable clinical symptoms and recurrent episodes. The prognosis of MELAS patients depends on timely diagnosis. Therefore, overall diagnosis of MELAS should be based on the maternal inheritance family history, clinical manifestation, and findings from serial MRI, muscle biopsy, and genetics.


Assuntos
Síndrome MELAS/diagnóstico , Humanos , Síndrome MELAS/genética , Imageamento por Ressonância Magnética
10.
Int J Clin Exp Pathol ; 8(1): 786-92, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25755775

RESUMO

BACKGROUND: MicroRNA-106b (miR-106b) is thought to be an oncogenic microRNA that promotes tumor growth and metastasis. The potential predictive value of miR-106b was studied in colonic cancer patients. METHODS: The expression of miR-106b was examined in 180 colonic cancer cases using in situ hybridization (ISH) technique and was evaluated semi-quantitatively by examining the staining index. The Correlation of miR-106b expression and clinic-pathological features was analyzed by Spearman Rank Correlation. Wilcoxon signed rank test was used for assessing the expression difference of miRNA-106b between colonic cancerous and para-cancerous ones, and their effects on patient survival were analyzed by a log-rank test and the Kaplan-Meier method. RESULTS: MiR-106b was higher expressed in para-cancerous tissues, compared with colonic cancerous ones (P < 0.001). A positive correlation of miR-106b levels between colonic and para-cancerous tissues was also observed (CC = 0.523, P < 0.001). Furthermore, the expression of miR-106b was not significantly correlated with clinic-pathological parameters, including gender, age, histological grade, tumor size, pT stage, pN stage, pM stage and pTNM stage of the patients. Histological grade was positively correlated with pT stage (P = 0.011), pN stage (P = 0.036) and pTNM stage (P = 0.009). Patients expressing high levels of miR-106b both in colonic cancer tissues and para-cancerous ones have a relatively longer survival time but the difference is not statistically significant (P = 0.16). CONCLUSIONS: The expression difference of miR-106b levels between colonic tissues and para-cancerous tissues is statistically significant, but the miR-106b levels were not quite correlated with clinic-pathological characteristics and overall survival times of patients with colonic cancer. Lower levels of miR-106b may be connected with neoplastic effects due to interference with TGF-ß signaling, providing evidence that down-regulation of miR-106b might also play an important role in the progression of the disease. The study results are consistent with the literature and support the notion that miR-106b is an oncogenic microRNA.


Assuntos
Adenocarcinoma/patologia , Biomarcadores Tumorais/genética , Neoplasias do Colo/patologia , MicroRNAs/biossíntese , Adenocarcinoma/genética , Adenocarcinoma/mortalidade , Adulto , Idoso , Biomarcadores Tumorais/análise , Neoplasias do Colo/genética , Neoplasias do Colo/mortalidade , Feminino , Humanos , Hibridização In Situ/métodos , Estimativa de Kaplan-Meier , Masculino , MicroRNAs/análise , Pessoa de Meia-Idade , Análise Serial de Tecidos
11.
Int J Neuropsychopharmacol ; 17(9): 1429-41, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24679950

RESUMO

The efficacy of chronic selective serotonin reuptake inhibitors (SSRIs) on depression is paralleled by the recovery of deficits in hippocampal neurogenesis related to sustained stress and elevated glucocorticoids. Previous studies have shown that atypical protein kinase C (aPKC) is implicated in the regulation of neurogenesis and the antidepressant response. Whether the specific aPKC isoforms (PKCζ, PKMζ and PKCι) are involved in SSRI-induced hippocampal neurogenesis and the underlying mechanisms is unknown. The present study shows that PKMζ and PKCι but not PKCζ are expressed in rat embryonic hippocampal neural stem cells (NSCs), whereas PKMζ but not PKCι expression is increased by the SSRI fluoxetine both in the absence and presence of the glucocorticoid receptor agonist dexamethasone. PKMζ shRNA significantly decreased neuronal proliferation and neuron-oriented differentiation, increased NSC apoptosis, and blocked the stimulatory effect of fluoxetine on NSC neurogenesis. Fluoxetine significantly increased PKMζ expression in hippocampal NSCs in a 5-hydroxytryptamine-1A (5-HT1A) receptor-dependent manner in both the absence and presence of dexamethasone. The PKMζ peptide blocker ZIP and MEK inhibitor U0126 significantly inhibited the increase in extracellular signal-regulated kinase 1/2 and cyclic adenosine monophosphate response element binding protein phosphorylation in the mitogen-activated protein kinase (MAPK) pathway and hippocampal NSC neurogenesis in response to fluoxetine and the 5-HT1A receptor agonist 8-OH DPAT. Collectively, our results suggest that the SSRI fluoxetine increases hippocampal NSC neurogenesis via a PKMζ-mediated mechanism that links 5-HT1A receptor activation with the phosphorylation of the downstream MAPK signaling pathway.


Assuntos
Antidepressivos de Segunda Geração/farmacologia , Fluoxetina/farmacologia , Hipocampo/citologia , Células-Tronco Neurais/efeitos dos fármacos , Neurogênese/efeitos dos fármacos , Proteína Quinase C/metabolismo , Animais , Diferenciação Celular/efeitos dos fármacos , Células Cultivadas , Dexametasona/farmacologia , Embrião de Mamíferos , Inibidores Enzimáticos/farmacologia , Regulação da Expressão Gênica/efeitos dos fármacos , Glucocorticoides/farmacologia , Piperazinas/farmacologia , Proteína Quinase C/genética , Piridinas/farmacologia , Ratos , Ratos Sprague-Dawley , Receptor 5-HT1A de Serotonina/genética , Receptor 5-HT1A de Serotonina/metabolismo , Serotonina/metabolismo , Antagonistas da Serotonina/farmacologia , Transdução de Sinais/efeitos dos fármacos
12.
Asian Pac J Cancer Prev ; 14(10): 5957-60, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24289608

RESUMO

BACKGROUND: Gliomas are the most common type of primary brain tumor in adults, and the X-ray repair complementing group 1 gene (XRCC1) is an important candidate gene influencing its risk. The objective of this study was to detect the influence of XRCC1 genetic polymorphisms on glioma risk. MATERIALS AND METHODS: A total of 629 glioma patients and 641 cancer-free subjects were enrolled in this case-control study. The genotypes of the c.1471G>A genetic polymorphism were determined by created restriction site-polymerase chain reaction (CRS-PCR) and DNA sequencing methods. The influence of the XRCC1 genetic polymorphism on glioma risk was evaluated by association analysis. RESULTS: Our data indicated that the alleles/genotype of this genetic variant was statistically associated with glioma risk. The AA genotype was statistically associated with the increased risk of glioma compared to the GG wild genotype (odds ratios (OR) = 1.89, 95% CI 1.25-2.87, P = 0.003). The allele-A may contribute to increased the susceptibility to glioma (OR = 1.23, 95% CI 1.04-1.46, P = 0.017). CONCLUSIONS: These preliminary findings indicate that the c.1471G>A genetic polymorphism of XRCC1 has the potential to influence glioma susceptibility, and might be used as molecular marker for assessing glioma risk.


Assuntos
Povo Asiático/genética , Biomarcadores Tumorais/genética , Neoplasias Encefálicas/genética , Proteínas de Ligação a DNA/genética , Predisposição Genética para Doença , Glioma/genética , Polimorfismo Genético/genética , Adulto , Neoplasias Encefálicas/epidemiologia , Estudos de Casos e Controles , China/epidemiologia , Feminino , Seguimentos , Genótipo , Glioma/epidemiologia , Humanos , Masculino , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase , Polimorfismo de Fragmento de Restrição , Prognóstico , Fatores de Risco , Proteína 1 Complementadora Cruzada de Reparo de Raio-X
13.
Int J Clin Exp Pathol ; 6(3): 476-84, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23411422

RESUMO

BACKGROUND: To study the expression levels and clinical significance of Argonaute2 (EIF2C2) on colonic carcinomas and normal tissues. METHODS: Colon tissue samples from 90 cases of colonic carcinomas and 90 normal subjects were accumulated and made into a tissue microarray containing 360 dots. Expression of Argonaute2 (EIF2C2) was detected by immunohistochemical staining of the tissue microarray. RESULTS: There was significant difference in the expression levels of Argonaute2 (EIF2C2) between colonic carcinomas and normal tissues (P<0.01). However, the expression of Argonaute2 (EIF2C2) was not related to sex, age, position, differentiation, lymphatic metastasis and clinical stage of the tumor (P>0.05). CONCLUSION: Abnormal expression of Argonaute2 (EIF2C2) may be correlated with colon tumorigenesis.


Assuntos
Adenocarcinoma/diagnóstico , Proteínas Argonautas/metabolismo , Colo/patologia , Neoplasias do Colo/diagnóstico , Análise Serial de Tecidos/métodos , Adenocarcinoma/metabolismo , Adenocarcinoma/secundário , Adulto , Idoso , Idoso de 80 Anos ou mais , Colo/metabolismo , Neoplasias do Colo/metabolismo , Feminino , Humanos , Linfonodos/patologia , Metástase Linfática , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Estudos Retrospectivos
14.
J Dig Dis ; 11(1): 50-4, 2010 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-20132431

RESUMO

OBJECTIVE: To investigate the difference of microRNA expression profiles between colonic cancer without lymph node metastasis and the para-cancerous control, to identify the specific microRNA associated with the cancer and to predict the carcinogenetic mechanism of microRNA on the basis of these results. METHODS: The microRNA (miRNA) were extracted and isolated from six specimens, including colonic cancerous and para-cancerous ones, all of which were confirmed to be without lymph node metastasis. Agilent microRNA microarrays consisting of 723 probes were used for screening the expression differences of microRNA. Data were analyzed using feature extraction software. The expression level of differentially expressed microRNA using quantitative real-time polymerase chain reaction (RT-PCR) was validated. RESULTS: A total of 14 miRNAs were found to be associated with colonic cancer, in which the expression of miR-106b, miR-135b, miR-18a, miR-18b, miR-196b, miR-19a, miR-224, miR-335, miR-424, miR-20a*, miR-301b and miR-374a were up-regulated and the expression of miR-378 and miR-378* were downregulated in colonic cancer tissues, compared with the para-cancerous control. The expression level of miR-18a and miR-135b were validated in accordance with the results of RT-PCR. CONCLUSION: The miRNAs are differentially expressed between colonic tumor tissues and para-cancerous tissues. Many of these miRNAs are expected to participate in the process of multiple tumorigenesis. These miRNAs could play an important role in the carcinogenesis of colon. These results provide new insights in human colorectal cancer genesis.


Assuntos
Neoplasias do Colo/genética , Perfilação da Expressão Gênica , MicroRNAs/metabolismo , Humanos , MicroRNAs/genética , Análise de Sequência com Séries de Oligonucleotídeos , Regulação para Cima
15.
Electrophoresis ; 26(19): 3631-40, 2005 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-16136528

RESUMO

The off-line coupling of polymer microfluidics to MALDI-MS is presented using electrospray deposition. Using polycarbonate microfluidic chips with integrated hydrophobic membrane electrospray tips, peptides and proteins are deposited onto a stainless steel target followed by MALDI-MS analysis. Microchip electrospray deposition is found to yield excellent spatial control and homogeneity of deposited peptide spots, and significantly improved MALDI-MS spectral reproducibility compared to traditional target preparation methods. A detection limit of 3.5 fmol is demonstrated for angiotensin. Furthermore, multiple electrospray tips on a single chip provide the ability to simultaneously elute parallel sample streams onto a MALDI target for high-throughput multiplexed analysis. Using a three-element electrospray tip array with 150 microm spacing, the simultaneous deposition of bradykinin, fibrinopeptide, and angiotensin is achieved with no cross talk between deposited samples. In addition, in-line proteolytic digestion of intact proteins is successfully achieved during the electrospray process by binding trypsin within the electrospray membrane, eliminating the need for on-probe digestion prior to MALDI-MS. The technology offers promise for a range of microfluidic platforms designed for high-throughput multiplexed proteomic analyses in which simultaneous on-chip separations require an effective interface to MS.


Assuntos
Técnicas Analíticas Microfluídicas/instrumentação , Peptídeos/análise , Proteínas/análise , Espectrometria de Massas por Ionização por Electrospray , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Polímeros/química
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