Safety of COVID-19 vaccine in patients with myasthenia gravis: a self-controlled case series study.

Background: The safety of COVID-19 vaccines has been clarified in clinical trials; however, some immunocompromised patients, such as myasthenia gravis (MG) patients, are still hesitant to receive vaccines. Whether COVID-19 vaccination increases the risk of disease worsening in these patients remains unknown. This study aims to evaluate the risk of disease exacerbation in COVID-19-vaccinated MG patients. Methods: The data in this study were collected from the MG database at Tangdu Hospital, the Fourth Military Medical University, and the Tertiary Referral Diagnostic Center at Huashan Hospital, Fudan University, from 1 April 2022 to 31 October 2022. A self-controlled case series method was applied, and the incidence rate ratios were calculated in the prespecified risk period using conditional Poisson regression. Results: Inactivated COVID-19 vaccines did not increase the risk of disease exacerbation in MG patients with stable disease status. A few patients experienced transient disease worsening, but the symptoms were mild. It is noted that more attention should be paid to thymoma-related MG, especially within 1 week after COVID-19 vaccination. Conclusion: COVID-19 vaccination has no long-term impact on MG relapse.

A correlation study affecting survival in patients after radical colon cancer surgery: A retrospective study.

The objective of this study was to explore the relevant factors affecting the 5-year survival rate of patients after radical colon cancer surgery, and to provide some basis for improving the quality of life and prognosis of colon cancer patients. The clinical data of 116 colon cancer patients who underwent treatment in our hospital from January 2017 to December 2017 were retrospectively selected. Using the date of performing surgical treatment as the starting point and the completion of 5 years after surgery or patient death as the end point, all patients were followed up by telephone to count the 5-year survival rate and analyze the influence of each factor with the prognosis of colon cancer patients. Of the 116 patients, 14 patients were lost to follow-up. Of the 102 patients with complete follow-up, 33 patients were died, with an overall 5-year survival rate of 67.6%. After univariate analysis, it was found that distant metastasis (χ2 = 10.493, P = .001), lymph node metastasis (χ2 = 25.145, P < .001), depth of muscle infiltration (χ2 = 14.929, P < .001), alcohol consumption (χ2 = 15.263, P < .001), and preoperative obstruction (χ2 = 9.555, P = .002) were significantly associated with the prognosis of colon cancer patients. Multivariate logistic analysis showed that distant metastasis (odds ratio [OR]: 1.932, 95% confidence intervals [CI]: 1.272-2.934, P = .002), lymph node metastasis (OR: 1.219, 95% CI: 1.091-1.362, P < .001), and obstruction (OR: 1.970, 95% CI: 1.300-2.990, P < .001) were significant independent risk factors affecting the prognosis in patients after radical colon cancer surgery. In summary, preoperative obstruction, lymph node metastasis, and distant metastasis are independent factors influencing 5-year survival rate after radical colon cancer surgery. Patients with risk factors should be followed up more closely and reasonable postoperative adjuvant chemotherapy regimens should be used to improve long-term survival.

Chinese expert consensus on the nursing management of the totally implantable venous access device.

The totally implantable venous access device (TIVAD) has been widely used in clinical nursing work in China. The use of TIVAD has significantly improved the safety of venous access and reduced the pain caused by a repeated puncture; however, it may also bring with it varying degrees of complications associated with the long-term insertion of TIVAD and the maintenance quality of the venous access. Standard maintenance of the venous access for TIVAD is very important for reducing complications and improving the efficacy and patient's quality of life. This consensus briefly describes the fundamental knowledge and operating procedures of TIVAD while focusing on the evaluation and management of perioperative nursing, the observation and treatment of complications, the operation methods, and precautions for maintenance of venous access, as well as health education. This agreement seeks to standardize the nursing care of TIVAD patients in China.

A high-integrated DNA biocomputing platform for MicroRNA sensing in living cells.

DNA logic computing has captured increasing interest due to its ability to assemble programmable DNA computing elements for disease diagnosis, gene regulation, and targeted therapy. In this work, we developed an aptamer-equipped high-integrated DNA biocomputing platform (HIDBP-A) with a dual-recognition function that enabled cancer cell targeting. Dual microRNAs were the input signals and can perform AND logic operations. Compared to the free DNA biocomputing platform (FDBP), the integration of all computing elements into the same DNA tetrahedron greatly improved logic computing speed and efficiency owing to the confinement effect reflected by the high local concentration of computing elements. As a proof of concept, the utilization of microRNA as the input signal was beneficial for improving the scalability and flexibility of the sequence design of the logic nano-platform. Given that the different microRNAs were over-expressed in cancer cells, this new HIDBP-A has great promise in accurate diagnosis and logic-controlled disease treatment.

Simultaneous Imaging of Dual microRNAs in Cancer Cells through Catalytic Hairpin Assembly on a DNA Tetrahedron.

Accurate detection and imaging of tumor-related microRNA (miRNA) in living cells hold great promise for early cancer diagnosis and prognosis. One of the challenges is to develop methods that enable the identification of multiple miRNAs simultaneously to further improve the detection accuracy. Herein, a simultaneous detection and imaging method of two miRNAs was established by using a programmable designed DNA tetrahedron nanostructure (DTN) probe that includes a nucleolin aptamer (AS1411), two miRNA capture strands, and two pairs of metastable catalytic hairpins at different vertexes. The DTN probe exhibited enhanced tumor cell recognition ability, excellent stability and biocompatibility, and fast miRNA recognition and reaction kinetics. It was found that the DTN probe could specifically enter tumor cells, in which the capture strand could hybridize with miRNAs and initiate the catalytic hairpin assembly (CHA) only when the overexpressed miR-21 and miR-155 existed simultaneously, resulting in a distinct fluorescence resonance energy transfer signal and demonstrating the feasibility of this method for tumor diagnosis.

Clinicopathologic features, treatment, survival, and prognostic factors of combined hepatocellular and cholangiocarcinoma: A nomogram development based on SEER database and validation in multicenter study.

PURPOSE: The aim of the study was to comprehensively understand the combined hepatocellular and cholangiocarcinoma (CHC) and develop a nomogram for prognostic prediction of CHC. METHODS: Data were collected from the Surveillance, Epidemiology and End Results (SEER) database (year 2004-2014). Propensity-score matching (PSM) was used to match the demographic characteristic of the CHC versus hepatocellular carcinoma (HCC) and intrahepatic cholangiocarcinoma (ICC). A nomogram model was established to predict the prognosis in terms of cancer specific survival (CSS). The established nomogram was externally validated by a multicenter cohort. RESULTS: A total of 71,756 patients enrolled in our study including 62,877 HCC patients, 566 CHC patients, and 8303 ICC patients. The CHC, HCC, and ICC are not exactly similar in clinical characteristic. After PSM, the CSS of CHC was better than HCC but comparable to ICC. Tumor size, M stage, surgery, chemotherapy, and surgery were independently prognostic factors of CHC and were included in the establishment of novel nomogram. The c-index of the novel nomogram in SEER training set and multicenter validation was 0.779 and 0.780, respectively, which indicated that the model was with better discrimination power. In addition, decision curve analyses proved the favorable potential clinical effect of the predictive model. Lastly, a risk classification based on nomogram also verified the reliability of the model. CONCLUSION: CHC had better survival than HCC but was comparable to ICC. The nomogram was established based on tumor size, M stage, chemotherapy, surgery, and radiotherapy and well validated by external multicenter cohort.

Chirality transfer of cysteine to the plasmonic resonance region through silver coating of gold nanobipyramids.

Here we report a chirality transfer of cysteine, which at first was to the plasmonic resonance region of gold nanobipyramids and then to that of Ag nanoshells with increasing growth of Ag layers, owing to the important role of the free Cys embedded within the Ag nanoshell. Our finding is helpful for developing new chiral plasmonic nanomaterials with the best designed asymmetric properties.

A portable personal glucose meter method for enzyme activity detection and inhibitory activity evaluation based on alkaline phosphatase-mediated reaction.

In this study, an effective and portable method for enzyme activity detection and inhibitory activity evaluation was developed based on the alkaline phosphatase (ALP)-mediated reaction in a personal glucose meter (PGM). In this method, ALP catalyzes the hydrolysis of substrate amifostine (WR-2721) to produce ethanethiol (WR-1065), which can trigger the reduction of ferricyanide (K3[Fe(CN)6]), an electron transfer mediator in glucose test strips, to ferrocyanide ([K4Fe(CN)6]) and generate a PGM-detectable signal. Thus, WR-1065 can be directly quantified by a PGM as simply as detecting glucose in blood. After being systematically optimized, the method was applied to evaluate the inhibitory activity of ten small-molecule compounds and six Cordyceps sinensis (CS) extracts on ALP. The results showed that adenosine-5-monophosphate and theophylline had high inhibitory activity, but two CS extracts have promotion potency on ALP with the values of -20.7 ± 1.3% and -46.6 ± 2.1%, respectively. Moreover, the binding sites and modes of small-molecule compounds to ALP were investigated by molecular docking, while a new substrate competitor with theoretically good inhibitory activity against ALP was designed by scaffold hopping. Finally, the accuracy of the PGM method for enzyme activity detection was assessed by detecting ALP from milk samples, and the recovery ranged from 87.7% to 116.9%. These results indicate that it is feasible to evaluate enzyme activity and the inhibitory activity of small-molecule compounds and CS extracts on ALP using a PGM based on ALP-mediated reaction. Graphical abstract.

Hierarchical Hybridization Chain Reaction for Amplified Signal Output and Cascade DNA Logic Circuits.

In this work, we propose a three-layer hierarchical hybridization chain reaction (3L hHCR) composed of 1stHCR, 2ndHCR, and 3rdHCR to achieve robust signal amplification efficiency and broaden the applied range of HCR-based systems. In principle, the execution of superior HCR generates the formation of the initiator (named as 2ndI or 3rdI) of the subordinate HCR that relies on the introduction of the target sequence (1stI). To avoid the high background signal of the 3L hHCR system, a strategy of "splitting reconstruction" was adopted. The initiator of the subordinate HCR was designed as two separate fragments (splitting) that are obtained together (reconstruction) for the motivation of the subordinate HCR after the completion of the superior HCR. The implementation of the entire 3L hHCR system generates significant fluorescence recovery that derives from the impediment of Förster resonance energy transfer between fluorophore and quencher; thus, ultrasensitive detection of 1stI in the range of 50 pM to 10 nM can be achieved. Surprisingly, when the concentration of 1stI is lower than 1 nM, the 3L hHCR shows excellent ability to discriminate against various concentrations of 1stI, which is better than that of the 2L hHCR I system. Due to the hierarchical self-assembly mechanism, the 3L hHCR can also be reliably operated as a cascade AND logic gate with a high specificity and molecular keypad lock with a prompt error-reporting function. Furthermore, the 3L hHCR-based molecular keypad lock also shows potential application in the accurate diagnosis of cancer. The 3 L hHCR shows visionary prospects in biosensing and the fabrication of advanced biocomputing networks.

Nucleolin-Targeted DNA Nanotube for Precise Cancer Therapy through Förster Resonance Energy Transfer-Indicated Telomerase Responsiveness.

Precise drug delivery holds great promise in cancer treatment but still faces challenges in controllable drug release in tumor cells specifically. Herein, a nucleolin-targeted and telomerase-responsive DNA nanotube for drug release was developed. First, a DNA nanosheet with four capture strands on its surface was prepared, which could bind and load ricin A chain (RTA). The RTA-loaded nanosheet was further converted into a DNA nanotube with a high Förster resonance energy transfer (FRET) efficiency in the presence of a Cy3-modified DNA fastener by hybridizing with the Cy5-modified DNA and another DNA-containing telomerase primer sequence along the long sides. Moreover, the aptamer of nucleolin was assembled on the DNA nanotube by combining with the hybrid chain at the terminal. The aptamer-functionalized and RTA-loaded DNA nanotube displayed enhanced tumor permeability and precise drug release in response to the telomerase in tumor cells, following the change of the FRET signal and RTA-induced cell death. Moreover, the DNA nanotube was applied successfully in vivo, and there was an obvious inhibition of tumor growth on xenograft-bearing mice following systemic administration, indicating that the constructed DNA nanotube represents a promising platform for precise RTA delivery in target cancer therapy.

Autophagy is involved in the replication of H9N2 influenza virus via the regulation of oxidative stress in alveolar epithelial cells.

BACKGROUND: Oxidative stress is an important pathogenic factor in influenza A virus infection. It has been found that reactive oxygen species induced by the H9N2 influenza virus is associated with viral replication. However, the mechanisms involved remain to be elucidated. METHODS: In this study, the role of autophagy was investigated in H9N2 influenza virus-induced oxidative stress and viral replication in A549 cells. Autophagy induced by H9N2 was inhibited by an autophagy inhibitor or RNA interference, the autophagy level, viral replication and the presence of oxidative stress were detected by western blot, TCID50 assay, and Real-time PCR. Then autophagy and oxidative stress were regulated, and viral replication was determined. At last, the Akt/TSC2/mTOR signaling pathways was detected by western blot. RESULTS: Autophagy was induced by the H9N2 influenza virus and the inhibition of autophagy reduced the viral titer and the expression of nucleoprotein and matrix protein. The blockage of autophagy suppressed the H9N2 virus-induced increase in the presence of oxidative stress, as evidenced by decreased reactive oxygen species production and malonaldehyde generation, and increased superoxide dismutase 1 levels. The changes in the viral titer and NP mRNA level caused by the antioxidant, N-acetyl-cysteine (NAC), and the oxidizing agent, H2O2, confirmed the involvement of oxidative stress in the control of viral replication. NAC plus transfection with Atg5 siRNA significantly reduced the viral titer and oxidative stress compared with NAC treatment alone, which confirmed that autophagy was involved in the replication of H9N2 influenza virus by regulating oxidative stress. Our data also revealed that autophagy was induced by the H9N2 influenza virus through the Akt/TSC2/mTOR pathway. The activation of Akt or the inhibition of TSC2 suppressed the H9N2 virus-induced increase in the level of LC3-II, restored the decrease in the expression of phospho-pAkt, phospho-mTOR and phospho-pS6 caused by H9N2 infection, suppressed the H9N2-induced increase in the presence of oxidative stress, and resulted in a decrease in the viral titer. CONCLUSION: Autophagy is involved in H9N2 virus replication by regulating oxidative stress via the Akt/TSC2/mTOR signaling pathway. Thus, autophagy maybe a target which may be used to improve antiviral therapeutics.

Online Liquid Microextraction Coupled with HPLC-ABTS for Rapid Screening of Natural Antioxidants: Case Study of Three Different Teas.

In the present study, an online liquid extraction coupled with high-performance liquid chromatography-2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (HPLC-ABTS) system for rapid screening of antioxidants in tea samples was proposed. As an example, the tea samples were firstly extracted by online HPLC extractor with mobile phase at 70°C, then the hyphenated HPLC-ABTS was used for the chromatographic separation on a Poroshell EC C18 column by 0.3% aqueous formic acid and acetonitrile with a gradient elution at 1.5 mL·min-1, and the UV and antioxidant chromatograms with detection wavelengths at 270 nm and 750 nm were recorded, respectively. The established system integrated the processes of online HPLC sample extraction, HPLC separation and online antioxidants detection, the total analysis time of which was <20 min. The developed method was successfully applied to samples of green tea, oolong tea and black tea. As a result, 11 antioxidants were found in tea samples, including gallocatechin, epigallocatechin, catechin, chlorogenic acid, epicatechin, epigallocatechingallate, epicatechingallate, rutin, 1,4,6-trigalloylglucose, quercetin-3-glycoside and kaempferol-3-glucoside. The combined online liquid microextraction and online HPLC-ABTS method is a rapid and green approach for the quality evaluation of tea.

DNA nanosheet as an excellent fluorescence anisotropy amplification platform for accurate and sensitive biosensing.

Recently, various inorganic nanomaterials have been used as fluorescence anisotropy (FA) enhancers for biosensing successfully. However, most of them are size-uncontrollable and possess an intensive fluorescence quenching ability, which will seriously reduce the accuracy and sensitivity of FA method. Herein, we report a two-dimensional DNA nanosheet (DNS) without fluorescence quenching effect as a novel FA amplification platform. In our strategy, fluorophore-labeled probe DNA (pDNA) is linked onto the DNS surface through the hybridization with the handle DNA (hDNA) that extended from the DNS, resulting in the significantly enhanced FA value. After the addition of target, the pDNA was released from the DNS surface due to the high affinity between the hDNA and target, and the FA was decreased. Thus, target could be detected by the significantly decreased FA value. The linear range was 10-50 nM and the limit of detection was 8 nM for the single-stranded DNA detection. This new method is general and has been also successfully applied for the detection of ATP and thrombin sensitively. Our method improved the accuracy of FA assay and has great potential to detect series of biological analytes in complex biosensing systems.

Enzyme-triggered fluorescence turn-off/turn-on of carbon dots for monitoring ß-glucosidase and its inhibitor in living cells.

Energy transfer engineering based on fluorescent probes for directly sensing enzyme activities are in great demand as enzyme-mediated transformations, which are central to all biological processes. Here, a fluorescence carbon dot (CD)-based assay exhibiting selective responses to the quantitation of ß-glucosidase and the effect of its inhibitor was developed. The most common substrate, para-nitrophenyl-ß-d-glucopyranoside (pNPG) was hydrolyzed by ß-glucosidase to release p-nitrophenol (pNP), which can efficiently quench fluorescence of CDs via an inner filter effect and electron transfer. However, in the presence of inhibitors of ß-glucosidase, the fluorescence intensity gradually recovered as the concentration of inhibitors increased. Therefore, the enzyme-triggered fluorescence turn-off/turn-on of specific CDs successfully achieved sensitive detection of ß-glucosidase and monitored the effect of its inhibitors. This new strategy was applied to detect ß-glucosidase and monitor ß-glucosidase inhibitor in hepatoma cells using cell imaging. All results suggest that the new method is sensitive and promising for use in cancer diagnosis and treatment.

[Analysis of chemical components in Cordyceps by online gradient extraction-HPLC].

Online gradient extraction-high performance liquid chromatography( HPLC) method was developed for simultaneous determination of high and low polar components in Cordyceps. The sample powder of Cordyceps was uniformly mixed with diatomaceous earth,packed into extraction tank,and installed into the HPLC system. Online gradient extraction was conducted with mobile phase at 70 ℃. The separation was performed on Zorbax SB-AQ( 4. 6 mm×150 mm,5 µm) column with 0. 1% formic acid solution-methanol as the mobile phase for gradient elution at 1. 0 mL·min~(-1). The column temperature was 30 ℃,and detection wavelength was set at 260 nm. The results showed that the high and low polar components in Cordyceps could be simultaneously extracted and separated by the developed method. Meanwhile,six high polar compounds( uracil,uridine,thymine,inosine,guanosine and adenosine) and one low polar compound( ergosterol) were identified by comparison with the reference peaks. The established method is rapid,stable and environment friendly,which is helpful to improve the quality evaluation level for Cordyceps.

Modulation of electroosmotic flow in capillary electrophoresis by plant polyphenol-inspired gallic acid/polyethyleneimine coatings: Analysis of small molecules.

Plant polyphenols can form functional coatings on various materials through self-polymerization. In this paper, a series of modified capillary columns, which possess diversity of charge characteristics for modulating electroosmotic flow (EOF), were prepared by one-step co-deposition of gallic acid (GA), a plant-derived polyphenol monomer, and branched polyethyleneimine (PEI). The physicochemical properties of the prepared columns were characterized by Fourier transform infrared spectroscopy (FT-IR), UV-Vis spectroscopy and scanning electron microscopy (SEM). The magnitude and direction of EOF of GA/PEI co-deposited columns were modulated by changing a series of coating parameters, such as post-incubation of FeCl3, co-deposition time, and deposited amounts of GA and PEI with different relative molecular mass (PEI-600, PEI-1800, PEI-10000, and PEI-70000). Furthermore, the separation efficiencies of the prepared GA/PEI co-deposited columns were evaluated by separations of small molecules, including organic acids, polar nucleotides, phenols, nucleic acid bases and nucleosides. Results indicated that modulating of EOF plays an important role in enhancing the separation performance and reversing the elution order of the analytes. Finally, the developed method was successfully applied to quantitative analysis of acidic compounds in four real samples. The recoveries were in the range of 73.5%-85.8% for citric acid, benzoic acid, sorbic acid, salicylic acid and ascorbic acid in beverage and fruit samples, 101.6%-104.9% for cinnamic acid, vanillic acid, and ferulic acid in Angelica sinensis sample, while 84.6%-97.8% for guanosine-5'-monophosphate, uridine-5'-monophosphate, cytosine-5'- monophosphate and adenosine-5'-monophosphate in Cordyceps samples. These results indicated that the co-deposition of plant polyphenol-inspired GA/PEI coatings can provide new opportunities for EOF modulation of capillary electrophoresis.

In vitro anti-platelet aggregation effects of fourteen fruits and vegetables.

In the present study, the anti-platelet aggregation activity of 14 vegetables and fruits was tested in vitro. The aqueous, 90% ethanol and ethyl acetate extracts, as well as concentrated juices of 14 foods (fruits and vegetables) were prepared, and the anti-platelet aggregation activity of those extracts was analyzed on a platelet aggregation analyzer in vitro with adenosine 5'-diphosphate (ADP), bovine thrombin (THR) and arachidonic acid (AA) as aggregation inducers, respectively. Aspirin (ASP) was used as the positive control. A number of the tested foods had inhibitory effects in concentration-dependent manner on platelet aggregations induced by various agonists. Especially, some foods such as lemon, leek, garlic, scallion, ginger, tomato and grapefruit showed good anti-platelet aggregation effect similar or higher than that of positive control group i.e. aspirin (ASP). The results of present study provide scientific reference for reasonable selection of daily dietary with supplementary curative effects or prevention of cardiovascular diseases (CVD).

Rapid Determination of Adenosine in Cordyceps by Online Extraction HPLC.

In this study, determination of adenosine in Cordyceps was accomplished by an online pressurized liquid extraction HPLC, and a poroshell column was employed for rapid HPLC separation. The Cordyceps sample powder was filled into a hollow guard column and extracted by thermal and pressurized water (75°C, 150 bar) for 3 min. Chromatographic separation was conducted on a poroshell 120 SB-Aq (4.6 × 50 mm, 2.7 µm) column and gradient elution was performed by water and methanol at a flow rate of 1.5 mL/min. The detection wavelength was set at 260 nm. The total measurement time including sample extraction and separation was <6 min. The calibration curve of adenosine was Y = 4.502 × 106X + 1.731 × 104, which showed good linearity (r2 > 0.9993) within tested range (4.03-80.5 µg/mL). The intra- and inter-day precisions of adenosine were 0.24% and 0.94%, respectively, and the recoveries of adenosine was 96.1% (relative standard deviation, 4.49%). The validated method was then applied to determinate adenosine in six batches of Cordyceps, and the contents of adenosine were 0.28-0.48 mg/g. The developed method is beneficial for the quality control of Cordyceps.

Preparation of titanium ion functionalized polydopamine coated ferroferric oxide core-shell magnetic particles for selective extraction of nucleotides from Cordyceps and Lentinus edodes.

In this study, a titanium ion (Ti4+) functionalized polydopamine coated ferroferric oxide (Fe3O4@PDA@Ti4+) core-shell magnetic particle was prepared for the selective extraction of nucleotides. Firstly, different metal ions including Ti4+, Zr4+, Fe3+, Al3+, Cu2+, Zn2+, Ni2+ and Mg2+ were respectively immobilized onto Fe3O4@PDA particles and their extraction efficiency for five nucleotides [cytidine-5'-monophosphate (CMP), uridine-5'-monophosphate (UMP), guanosine-5'-monophosphate (GMP), thymidine-5'-monophosphate (TMP) and adenosine-5'-monophosphate (AMP)] were compared. Among these prepared materials, Fe3O4@PDA@Ti4+, which exhibited the highest extraction efficiency for nucleotides, was further characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy and energy dispersive X-ray spectroscopy. After being optimized of the extraction parameters including adsorbent amounts, extraction time, extraction temperature, type and concentration of the eluent, the prepared Fe3O4@PDA@Ti4+ magnetic particles were successfully applied for the selective extraction and determination of CMP, UMP, GMP, TMP and AMP in Cordyceps and Lentinus edodes. Good linearity (varying from 0.063 to 19.000 µg/mL, R2 > 0.999) and low limit of detection (LODs) (ranging between 0.0047 and 0.0141 µg/mL) for target analytes were achieved. These results demonstrated that the synthesized material in this study had potential for selective extraction of phosphorylated small molecular compounds in complicated matrix.

Potential target-related proteins in rabbit platelets treated with active monomers dehydrocorydaline and canadine from Rhizoma corydalis.

BACKGROUND: Dehydrocorydaline (DHC) and canadine (THB) are two active alkaloid compounds in Corydalis yanhusuo (Y.H. Chou & Chun C. Hsu) W.T. Wang ex Z.Y. Su & C.Y. Wu (Papaveraceae) (Rhizoma Corydalis). DHC and THC were previously shown to exert anti-platelet aggregation effect dose-dependently, but their exact mechanisms had not yet been addressed. Therefore, it is essential to study the mechanisms of DHC and THB affecting on platelet's function. PURPOSE: To investigate the anti-platelet effects and corresponding signal cascades of DHC and THB on platelet aggregation. METHODS: Firstly, in vitro anti-platelet aggregation of DHC and THB induced by different agonists including thrombin (THR), adenosine diphosphate (ADP) and arachidonic acid (AA) were determined through turbidimetry method. Then the possible target-related platelet proteins after treated with DHC/THB were separated and identified by two dimensional gel electrophoresis (2-DE) and MALDI-TOF-MS/MS analysis, respectively. Finally, the signal cascades network induced by DHC/THB were predicted through functional analysis of these proteins along with the determination of platelet DAG concentration. RESULTS: The platelet aggregation stimulated by THR, ADP and AA were inhibited by DHC and THB dose-dependently to a certain degree. Meanwhile, DHC and THB had the strongest effect on ADP- and THR-induced platelet aggregation respectively. In addition, treatment of these two compounds caused regulations of about sixty proteins in platelet, including cytoskeleton proteins, cell signaling proteins, proteins related to material energy metabolism, etc. CONCLUSIONS: Using proteomic analysis combined with platelet aggregation test and ELISA, this study was successful in exploring the possible mechanisms of DHC/THB on platelet aggregation. DHC might inhibit platelet aggregation by a mechanism involving the ADP receptors P2Y1 and P2Y12, and the effect of THB on platelet function may be related to its binding to THR receptor PAR1 for mediated Gi signaling pathway. These results provide fundamental information for the anti-thrombotic effect of RC.