To explore novel ADP receptor inhibitors with anti-thrombotic activity, eighteen compounds were synthesized and their structures were confirmed by 1H NMR and MS. The results showed that the activity of compound C1 was superior to ticlopidine in platelet aggregation inhibition tests in vivo and worthy for further investigation. Compounds A4, B2, C4 and C7 possessed moderate platelet aggregation inhibitory activities.
Animals ; Male ; Molecular Structure ; Platelet Aggregation ; drug effects ; Platelet Aggregation Inhibitors ; chemical synthesis ; chemistry ; pharmacology ; Purinergic P2Y Receptor Antagonists ; chemical synthesis ; chemistry ; pharmacology ; Random Allocation ; Rats ; Rats, Wistar ; Thienopyridines ; chemical synthesis ; chemistry ; pharmacology

CD43 (sialophorin, leukosialin) is a heavily sialylated surface protein expressed on most leukocytes and platelets including T cells. Although CD43 antigen is known to have multiple and complex structure, exact function of CD43 in each cell type is not completely understood. Here we evaluated the role of CD43 in Fas (CD95)-induced cell death in human T lymphoblastoid cell line, Jurkat. Crosslinking CD43 antigen by K06 mAb increased the Fas-mediated Jurkat cell apoptosis and the augmentation was inhibited by treatment with caspase inhibitors. Further, CD43 signaling of Jurkat cells induced Fas oligomerization on the cell surfaces implying that CD43 ligation have effects on early stage of Fas-induced T cell death. These also suggest that CD43 might play an important role in contraction of the immune response by promotion of Fas-induced apoptosis in human T cells.
Receptor Aggregation/immunology ; Jurkat Cells ; Humans ; Caspases/metabolism ; Apoptosis/*immunology ; Antigens, Surface/metabolism ; Antigens, CD95/metabolism/*physiology ; Antigens, CD43/metabolism/*physiology ; Antibodies, Monoclonal/metabolism

Animals ; Cardiovascular Diseases ; etiology ; metabolism ; Humans ; Inflammation ; metabolism ; Periodontitis ; complications ; metabolism ; microbiology ; Platelet Aggregation ; physiology ; Porphyromonas gingivalis ; pathogenicity ; RNA, Messenger ; metabolism ; Receptor, PAR-1 ; metabolism ; Receptor, PAR-2 ; genetics ; metabolism ; Receptors, Proteinase-Activated ; metabolism ; Receptors, Thrombin ; metabolism

We studied the aggregation of a recombinant engineering antibody (chA21). Anti-ErbB2 antibody chA21 was produced by fusing single-chain Fv (scFv) with human IgG1 Fc fragment, and it was proved to be a drug candidate for cancer therapy. We characterized the aggregation of chA21 by high performance sized-exclusive chromatography (HPSEC), dynamic light scattering (DLS), SDS-PAGE, indirect ELISA assay, and compared the influence of temperature and additive on the level of aggregation and binding activity. Conformation changes of different levels of aggregation were also analyzed via circular dichroism (CD). Finally, we analyzed which part of chA21 was involved in aggregation by cleaving it into scFv and Fc fragments. The results showed that chA21 could form aggregates in the storage solution. The aggregates interacted through non-covalent bonds and remained binding activity. Temperature and additive could slightly affect the level of aggregation and binding activity, while the conformations of chA21 were stable. Aggregation propensity of scFv fragment was almost same as chA21, indicating that scFv may be the major part to form the aggregates. The research on aggregation may be helpful to develop a suitable formulation for chA21 clinical application as well as provide direction for future antibody design and reconstruction.
Antibodies ; chemistry ; metabolism ; Humans ; Immunoglobulin Fc Fragments ; chemistry ; metabolism ; Immunoglobulin Variable Region ; chemistry ; metabolism ; Protein Conformation ; Protein Engineering ; methods ; Receptor Aggregation ; immunology ; Receptor, ErbB-2 ; chemistry ; immunology ; Recombinant Proteins ; biosynthesis ; chemistry ; genetics ; immunology

BACKGROUND: Dual therapy with aspirin and clopidogrel has emerged as the gold standard therapy for patients treated with drug-eluting stents (DES). However, there is variability in patients' responses to this antiplatelet therapy, and some patients continue to show ischemic recurrences after therapy. The purpose of the study was to compare the simultaneously obtained results of various platelet-function tests for assessing the prevalence of antiplatelet resistance in coronary artery disease patients undergoing DES therapy. METHODS: A total of 66 patients were administered a loading dose of aspirin, clopidogrel, and cilostazol at least 12 hr before stenting. The results of VerifyNow (Accumetrics, USA), multiplate analyzer (Dynabyte Medical, Germany), and vasodilator-stimulated phosphoprotein/P2Y12 (Biocytex, France) assays were compared with those of light transmission aggregometry (LTA) analysis. RESULTS: The P2Y12 reaction units and P2Y12% inhibition values obtained using the VerifyNow assay showed strong correlation (r) with the results of the LTA analysis. All tests results showed low concordance in defining the antiplatelet resistance in patients, and the degrees of agreement were as follows: 0 for aspirin reaction units; 0.25, P2Y12% inhibition; 0, aspirin-sensitive patients' identification test; 0.21, ADPtest; and 0.14, platelet reactivity index, expressed as the kappa statistics. The prevalence of aspirin and clopidogrel resistances in patients resulted in remarkable variations, from 0% to 22.7% and from 9.1% to 48.5%, respectively. CONCLUSIONS: The clinical usefulness of the different assays for the correct classification of patients in terms of antiplatelet resistance remains unclear. Further studies are required to determine the best method for correlating the occurrences of adverse ischemic events.
Aged ; Aspirin/*administration & dosage ; Coronary Artery Disease/*drug therapy ; Drug Resistance ; Drug Therapy, Combination ; Drug-Eluting Stents ; Female ; Humans ; Male ; Middle Aged ; Platelet Aggregation/drug effects ; Platelet Aggregation Inhibitors/*administration & dosage ; Platelet Function Tests ; Purinergic P2Y Receptor Antagonists/administration & dosage ; Receptors, Purinergic P2Y12/metabolism ; Tetrazoles/administration & dosage ; Ticlopidine/administration & dosage/*analogs & derivatives

OBJECTIVE: Dual antiplatelet therapy (DAPT) with aspirin and a P2Y12 receptor inhibitor is the cornerstone of treatment in patients with acute coronary syndromes (ACS) and in those undergoing percutaneous coronary intervention (PCI). In current clinical situation, availability of different oral P2Y12 inhibitors (clopidogrel, prasugrel, and ticagrelor) has enabled physicians to switch among therapies owing to specific clinical scenarios. Although optimum time, loading dose and interval of transition between P2Y12 inhibitors is still controversial and needs further evidence, switching between oral inhibitors frequently occurs in clinical practice for several reasons. DATA SOURCES: This review was based on data in articles published in PubMed up to June 2018, with the following keywords "antiplatelet therapy", "ACS", "PCI", "ticagrelor", and "clopidogrel". STUDY SELECTION: Original articles and critical reviews on de-escalation strategy in ACS patients after PCI were selected. References of the retrieved articles were also screened to search for potentially relevant papers. RESULTS: Safety concerns associated with switching between antiplatelet agents, has prompted the use of clopidogrel for patients with ACS especially after PCI as a de-escalation strategy. Practical considerations for de-escalating therapies in patients with ACS such as reducing dose of P2Y12 inhibitors or shortening duration of DAPT (followed by aspirin or P2Y12 receptor inhibitor monotherapy) as potential options are yet to be standardized and validated. CONCLUSIONS Current review will provide an overview of the pharmacology of common P2Y12 inhibitors, definitions of de-escalation and different de-escalating strategies and its outcomes, along with possible direction to be explored in de-escalation.
Acute Coronary Syndrome ; drug therapy ; therapy ; Aspirin ; therapeutic use ; Diamines ; therapeutic use ; Humans ; Percutaneous Coronary Intervention ; Platelet Aggregation Inhibitors ; therapeutic use ; Purinergic P2Y Receptor Antagonists ; therapeutic use ; Thiazoles ; therapeutic use

OBJECTIVE: To evaluate the effect of asymmetric dimethylarginine (ADMA) and the results of losartan intervention on platelet-aggregation in spontaneous hypertensive rats. METHODS: Spontaneous hypertensive rats (SHR) were randomly assigned into 3 groups: SHR control group, L-arginine treatment group (L-arg) and losartan (los) treatment group, each group consisting of 16 rats. Another 16 Wistar Kyoto rats (WKY) served as normal control group. The L-arginine and losartan treatment groups received 1.0 g/kg L-arginine or 30 mg/kg losartan in 10 mL/kg distilled water daily through gastric tube for 2 weeks respectively, while the SHR and WKY groups received distilled water alone. All the rats took tap water and standard feed freely during the experimental period. Systolic blood pressure (SBP) was monitored by the tail-cuff method. At the end of the 2-week intervention, all the rats were sacrificed and the blood samples were collected from the carotid artery. The platelet-aggregation-rate, NO levels, eNOS activity, and ADMA levels both in the plasma and the platelets were measured. We got other platelet samples from the SD rats and incubated the platelets with blood vascular endothelium from the above 4 groups of experimental rats and the platelet-aggregation-rate was monitored as well. RESULTS: (1) Systolic blood pressure of the SHR was significantly higher, compared with that of the WKY (P<0.01), which were significantly reduced both in the L-arginine and losartan groups (P<0.01). (2) Platelet-aggregation-rate of the SHR was significantly higher, compared with that of WKY (P<0.01), which was significantly reduced both in the L-arginine and losartan groups (P<0.01). (3) NO levels both in the plasma and the platelets of the SHR were lower, compared with those of the WKY (P<0.05); and were elevated significantly both in the L-arginine and losartan groups,compared with those of the SHR (P<0.05); (4) Both the plasma and the platelet eNOS activities of SHR followed the same pattern of the NO levels in these groups (P<0.01). (5) In contrast, the plasma and platelet ADMA levels showed a reverse pattern (P<0.05). (6) Platelets from the SD rats incubated with vascular endothelium of WKY exhibited lower platelet-aggregation-rate,compared with the platelets incubated with SHR vascular endothelium (P<0.05); Platelet-aggregation-rate of the SHR group increased, compared with that of the WKY group (P<0.05); Platelet-aggregation-rate both of L-arginine and losartan groups reduced, compared with that of the SHR group (P<0.05). CONCLUSION High levels of ADMA both in the plasma and in the platelets of SHR are associated with the decline of eNOS activity and NO levels, which might be an important reason for the increased platelet-aggregation-rate. Intervention with Losartan can reduce the platelet-aggregation-rate simultaneously with its known anti-hypertensive effect. The possible mechanism might be that losartan can enhance the eNOS activity and elevate NO levels through the suppression of ADMA.
Angiotensin II Type 1 Receptor Blockers ; therapeutic use ; Animals ; Antihypertensive Agents ; therapeutic use ; Arginine ; analogs & derivatives ; blood ; Hypertension ; blood ; drug therapy ; Losartan ; therapeutic use ; Male ; Platelet Aggregation ; drug effects ; Rats ; Rats, Inbred SHR ; Rats, Inbred WKY

Acute Coronary Syndrome/drug therapy* ; Aged ; Clopidogrel/therapeutic use* ; Humans ; Percutaneous Coronary Intervention ; Platelet Aggregation Inhibitors/therapeutic use* ; Purinergic P2Y Receptor Antagonists/therapeutic use* ; Ticagrelor/therapeutic use* ; Treatment Outcome

Objective: To explore the medication compliance for secondary prevention drugs and long-term prognosis of patients with acute coronary syndrome (ACS) undergoing percutaneous coronary intervention (PCI) between hospitals in different regions of China. Methods: The Optimal Antiplatelet Therapy for Chinese Patients with Coronary Artery Disease (OPT-CAD) study was a prospective, multi-center and registered study. Patients diagnosed as ACS and underwent PCI in OPT-CAD study were selected. Taking the Yangtze River as the dividing line between the south and the north of China, these patients were divided into two groups according to the hospitals where the patients visited, namely the southerns region group (n=1 958) and the northerns region group (n=5 091). In order to reduce selection bias and potential confounding factors, the patients in the two groups were matched by the tendency score, and the patients in the two groups were matched by the 1: 1 nearest match method according to the tendency score. The main endpoint of this study was the major adverse cardiovascular and cerebrovascular events (MACCE) occurring within 5 years after discharge, namely the composite endpoint of cardiac death, myocardial infarction, and/or ischemic stroke. Secondary endpoints were all-cause death, cardiac death, myocardial infarction, ischemic stroke, and type 2, 3, and 5 bleeding events defined by the Academic Research Consortium on Hemorrhage (BARC) within 5 years. The secondary preventive drugs was recorded, including antiplatelet drugs, statins, beta blockers, angiotensin converting enzyme inhibitors/angiotensinⅡreceptor blockers (ACEI/ARB), etc. Before and after the matching, the secondary preventive medication and the incidence of clinical events of the two groups were compared. Results: A total of 7 049 ACS patients, including 1 958 patients in the southern region group and 5 091 patients in the northern region group were enrolled in this study. There were 5 319 males (37.9%), and the aged was (60.7±6.7) years. After propensity score matching, there were 1 324 cases in each group. Before matching, in the northern region group, the proportion of smoking, hypertension and diabetes, previous history (myocardial infarction, PCI and stroke) and family history of coronary heart disease were higher (all P<0.05). The proportion of complex lesions, diffuse lesions, small vessel lesions and thrombotic lesions in the northern region group was higher than that in the southern region group (all P<0.05). Sixty months after discharge, the antiplatelet patterns were quite different between patients in the northern and southern region group (P<0.001). The proportion of clopidogrel monotherapy in the southern region group was higher than that in the northern region group (9.8% (130/1324) vs. 1.1% (14/1324)), while the proportion of aspirin monotherapy in the northern region group was higher than that in the southern region group (67.4% (893/1324) vs. 46.5% (616/1324)). As for the use of other secondary prophylactic drugs, the proportion of patients in southern region group receiving beta blockers (24.5% (325/1324) vs. 16.8% (222/1324), P<0.001) and ACEI/ARB (19.4% (257/1324) vs. 10.0% (133/1324), P<0.001) was higher than that in northern region group. After matching, the incidence of MACCE (8.4%(111/1 324) vs.6.2% (82/1 324), P=0.030) and BARC 2, 3 and 5 bleeding (6.0% (80/1 324) vs. 4.0% (53/1 324), P=0.020) was higher in patients in northern region group. Conclusions: ACS patients who undergo PCI in northern area hospital is at higher prevalence of comorbidities and complicated coronary artery lesions compared to patients in the southern area hospital, and the drug compliance is worse than that in southern area, and the prognosis is also relatively poor.
Acute Coronary Syndrome/drug therapy* ; Aged ; Angiotensin Receptor Antagonists ; Angiotensin-Converting Enzyme Inhibitors ; China ; Humans ; Male ; Medication Adherence ; Middle Aged ; Percutaneous Coronary Intervention ; Platelet Aggregation Inhibitors/therapeutic use* ; Prospective Studies ; Secondary Prevention ; Treatment Outcome

BACKGROUNDAngiotensin type 1 receptor (AT 1 R) antagonists are extensively used for blood pressure control in elderly patients with hypertension. This study aimed to investigate the inhibitory effects of AT 1 R antagonist valsartan on platelet aggregation and the occurrence of cardio-cerebral thrombotic events in elderly patients with hypertension.

METHODSTwo-hundred and ten patients with hypertension and aged > 60 years were randomized to valsartan (n = 140) or amlodipine (n = 70) on admission. The primary endpoint was platelet aggregation rate (PAR) induced by arachidonic acid at discharge, and the secondary endpoint was the rate of thrombotic events including brain infarction and myocardial infarction during follow-up. Human aortic endothelial cells (HAECs) were stimulated by angiotensin II (Ang II, 100 nmol/L) with or without pretreatment of valsartan (100 nmol/L), and relative expression of cyclooxygenase-2 (COX-2) and thromboxane B 2 (TXB 2 ) and both p38 mitogen-activated protein kinase (p38MAPK) and nuclear factor-kB (NF-kB) activities were assessed. Statistical analyses were performed by GraphPad Prism 5.0 software (GraphPad Software, Inc., California, USA).

RESULTSPAR was lower after treatment with valsartan (11.49 ± 0.69% vs. 18.71 ± 2.47%, P < 0.001), associated with more reduced plasma levels of COX-2 (76.94 ± 7.07 U/L vs. 116.4 ± 15.89 U/L, P < 0.001) and TXB 2 (1667 ± 56.50 pg/ml vs. 2207 ± 180.20 pg/ml) (all P < 0.001). Plasma COX-2 and TXB 2 levels correlated significantly with PAR in overall patients (r = 0.109, P < 0.001). During follow-up (median, 18 months), there was a significantly lower thrombotic event rate in patients treated with valsartan (14.3% vs. 32.8%, P = 0.002). Relative expression of COX-2 and secretion of TXB 2 with concordant phosphorylation of p38MAPK and NF-kB were increased in HAECs when stimulated by Ang II (100 nmol/L) but were significantly decreased by valsartan pretreatment (100 nmol/L).

CONCLUSIONSAT 1 R antagonist valsartan decreases platelet activity by attenuating COX-2/TXA 2 expression through p38MAPK and NF-kB pathways and reduces the occurrence of cardio-cerebral thrombotic events in elderly patients with hypertension.

Aged ; Aged, 80 and over ; Angiotensin Receptor Antagonists ; therapeutic use ; Blood Platelets ; drug effects ; Blotting, Western ; Cell Line ; Cyclooxygenase 2 ; blood ; Female ; Humans ; Hypertension ; drug therapy ; Male ; Platelet Aggregation ; drug effects ; Real-Time Polymerase Chain Reaction ; Tetrazoles ; therapeutic use ; Thrombosis ; blood ; drug therapy ; Thromboxane B2 ; blood ; Valine ; analogs & derivatives ; therapeutic use ; Valsartan