EFFECT OF 764－3 ON AGGREGATION AND CALCIUM MOVEMENTS IN AEQUORIN－LOADED HUMAN PLATELETS

Washed human platelets were loaded with the Ca2+-sensitive photoprotein, aequorin. using hypoosmotic shock treatment-technique. Then aggregation and cytoplasmic ionized calcium concentration ( [Ca2+] i) changes in response to collagen or thrombin were measured simultaneously in the aequorin-loaded human platelets with a Platelet Ionized Calcium Aggregometer. 764-3. an active component isolated from the Chinese medicinal herb Salvia Miltiorrhiza Bge, inhibited platelet [Ca2+]i rise as well as aggregation evoked by collagen or thrombin in the presence of extracellular Ca2+. After the extracellular Ca2+. was removed by addition of EGTA, collagen or thrombin. causing no aggregation. still elicited platelet [Ca2+] i rise which reflected Ca2+ mobilization from intraplatelet stores. Under this condition, 764-3 could also suppress platelet [Ca2+] i rise. Analysis shows that 764-3 inhibrts platelet Ca2+ influx and Ca2+ mobilization with similar potency. which accounts for its suppression of platelet [Ca2+] i rise, and must contribute to its inhibition of platelet aggregation.

Effects of Berbamine on PAF Production in Human Neutrophils and on Platelet Aggregation

The effects of berbamine, an alkaloid of dibenzylisoquinoline, on PAF produc tion in human neutrophils and on platelet aggregation induced by PAF were studied and compared with those of the calcium antagonist verapamil. Preincubation with berbamine (50 mmol / L, 100 mmol / L) or verapamil (10 mmol / L, 100 mmol / L) was shown to significantly inhibit A 23187 stimulated PAF synthesis. Berbamine and verapamil were found to inhibit platelet aggregation induced by PAF 70 pmol / L in a dose dependent manner. These results suggest that the inhibitory effects of berbamine and verapamil on A 23187 stimulated PAF synthesis in human neutrophils and PAF induced platelet aggregation are possibly brought about by inhibiting cellular calcium influx.

Inhibitory Effect of β-Elemene Emulsion on Platelet Aggregation and its Mechanism

为阐明β榄香烯的抗血小板作用，本文分别采用比浊法和放免法测定大鼠连续ｉｐ７ｄβ榄香烯乳６．２５～１２．５ｍｇ·ｋｇ－１·ｄ－１后对血小板聚集、血浆ｋｅｔｏＰＧＦ１α和ＴＸＢ２水平的影响。结果表明，本品分别使凝血酶、花生四烯酸和ＡＤＰ诱导血小板最大聚集率下降３８．３％～４２．６％，１４．７％～１９．１％和７．２％～１０．８％，血浆ＴＸＢ２从８８ｎｇ·Ｌ－１下降至７２ｎｇ·Ｌ－１，ｋｅｔｏＰＧＦ１α从１７．５ｎｇ·Ｌ－１增加至２０．９ｎｇ·Ｌ－１。提示ＴＸＢ２降低和ｋｅｔｏＰＧＦ１α值增加是其抑制血小板聚集的作用机制之一。

EFFECTS OF NIMODIPINE ON PLATELET AGGREGATION AND THE ACTIVITY OF ENZYMES IN ARACHIDONIC ACID METABOLISM

The effects of nimodipine on platelet aggregation and arachidonic acid(AA)metabolism were studied in order to explore its effect on patients with thrombosis or cardiovas- cular disease.The results indicate that nimodipine(50-350μmol/L)significantly inhibits platelet aggregation induced by ADP,AA,and ionophore A23187 in a dose dependent manner.The inhibitory effects induced by ionophore A23187 could be partially antagonized by calcium(1 mmol/L).When the substrate was AA and the enzyme was supplied by pig lung microsomes,nimodipine(50-400μmol/L)significantly reduced the generation of TXB_2 and 6-keto-PGF_(1a) in parallel.When the substrate was prostaglandin endoperoxide, however,the levels of TXB_2 and 6-keto-PGF_(1a)were not significantly altered in the same concentration range.The results suggest that nimodipine is a cyclooxygenase inhibitor,and its ability to inhibit platelet aggregation is related to its calcium blocking effect.

Effects of Total Flavone of Abelmoschl Manihot L.Medic on the Function of Platelets and Its Mechanism

Objective: To study the effects of total flavone of Abelmoschl Manihot L.Medic (TFA) on the function of platelets and to explore its mechanism. Methods: Rat models of artery-veins bypassing thrombus formation were used. The platelets of rabbits were collected. Platelet aggregation was induced by collagen and intracellular calcium ion concentration ([Ca 2+ ]i) was assayed by Fura-2 method. Results: TFA (25, 50, 100 mg/kg) significantly and dose-dependently reduced the weight of thrombus. TFA (0.025, 0.05, 0.1 mg/ml) possessed dose-dependant inhibitory effects on rabbits' platelet aggregation induced by collagen. TFA significantly reduced the resting and CaCl 2-induced increase of free intracellular calcium concentration ([Ca 2+ ]i) in rabbit platelet in vitro . Conclusion: TFA has an antiplatelet effect via the inhibition on the influx of Ca 2+ .

Inhibitory effects and mechanisms of high molecular-weight phlorotannins from Sargassum thunbergii on ADP-induced platelet aggregation

We evaluated the effects of high molecular-weight phlorotannins from Sargassum thunbergii(STP) on ADP-induced platelet aggregation and arachidonic acid(AA) metabolism in New Zealand white rabbits and Wistar rats.The inhibition of STP on platelet aggregation was investigated using a turbidimetric method,and the levels of the terminal products of AA metabolism were measured using the corresponding kits for maleic dialdehyde(MDA),thromboxane B2(TXB2) and 6-keto-prostaglandin F1α(6-keto-PGF1α) by colorimetry and radioimmunoassay,as appropriate.We found that STP could inhibit ADP-induced platelet aggregation,and the inhibitory ratio was 91.50% at the STP concentration of 4.0 mg/mL.Furthermore,STP markedly affected AA metabolism by decreasing the synthesis of MDA(P<0.01) and increasing the synthesis of 6-keto-PGF1α,thus changing the plasma TXB2/6-keto-PGF1α balance when the platelets were activated(P<0.01).Therefore,STP altered AA metabolism and these findings partly revealed the molecular mechanism by which STP inhibits ADP-induced platelet aggregation.

Synthesis of Novel Ligustrazine Derivatives as Potential Platelet Aggregation Inhibitors

A series of novel ligustrazine derivatives were synthesized. These compounds have not been reported in literature, and their chemical structures were confirmed by IR, ^1H NMR and ESI-MS. The preliminary antiplatelet aggregation screening results demonstrated that the compounds 7a, 7b and 7c showed higher potency than ligustrazine.

A practical synthesis of sarpogrelate hydrochloride and in vitro platelet aggregation inhibitory activities of its analogues

A convenient approach for the preparation of sarpogrelate hydrochloride was developed.Two series of sarpogrelate hydrochloride analogues were designed and synthesized in order to improve their platelet aggregation inhibitory activities, biological tests suggested that these compounds have platelet aggregation inhibitory activities to some extent.

Platelet aggregation responses in type 2 diabetic patients

Diabetes mellitus (DM) is associated with platelet dysfunction. In diabetic patients, alterations in platelet functions, especially increased platelet agregation, have been suggested to cause increasing in cardiovascular morbidity and mortality or in accelaretion of athersclerotic process. In this study, we aimed to investigate the platelet aggregation response alterations and the effects of DM duration, HbA1c, treatment options among the patients with Type 2 DM. Fortyfive patients (case group;21 male, 24 female) with Type 2 DM and forty-eight healthy individuals (control group;22 male, 26 female) were included in this study. Platelet aggregation was determinated with Chorono-log 500 (USA) named device by using Chorono-log/ADP, Chorono-log/ collagen and Chorono-log/epinephrine kits. ADP-induced platelet aggregation was significantly higher in the case group compared with control group (p 【0.05). Epinephrine induced platelet aggregation were significant in negatively correlation with the diabetes duration (P 【0.05). Platelet aggregation responses did not differ according to their treatment type (sulphonylurea or insulin) was statistically insignificiant among the case groups (p 】0.05). In conclusion, our findings supported that type 2 diabetes may interfere with platelet functions without any relationship age, gender, the treatment types and the regulation levels. These findings supports that existence potential new factors or mechanism affecting platelet agregation. The subject requires more detailed studies in the future.

Effects of procainamide on adenosine diphosphate-induced platelet aggregation and thromboxane B_2 production in rabbits in vitro

Turbidimetry and radioimmunoassay were used to study the effects of procainamide (PA ) onadenosine diphosphate (ADP)-induced rabbit platelet aggregation and thromboxane B2 (TXB2) production invitro. PA 8. 5--544. 0 μmol L-1 inhibited ADP-induced platelet aggregation and TXB2 production, and theinhibition rates were 26. 7% -- 66. 7 % and 21. 4 % -- 70. 1 %, respectively. There was positive correlation between PA concentration and its efficiency in inhibiting the platelet aggregation and TXB2 production, and alsobetween the inhibition rates of platelet aggregation and that of TXB2 production. The three linear equationsand main parameters were The results indicate that PA could significantly inhibit ADP--induced platelet aggregation and TXB2 production in rabbits.

Clinical significance of platelet mononuclear cell aggregates in patients with sepsis and acute respiratory distress syndrome

BACKGROUND The diagnosis of sepsis combined with acute respiratory distress syndrome(ARDS)has increased owing to the enhanced awareness among medical profes-sionals and the continuous development of modern medical technologies,while early diagnosis of ARDS still lacks specific biomarkers.One of the main patho-genic mechanisms of sepsis-associated ARDS involves the actions of various pathological injuries and inflammatory factors,such as platelet and white blood cells activation,leading to an increase of surface adhesion molecules.These adhesion molecules further form platelet-white blood cell aggregates,including platelet-mononuclear cell aggregates(PMAs).PMAs has been identified as one of the markers of platelet activation,here we hypothesize that PMAs might play a potential biomarker for the early diagnosis of this complication.METHODS We selected 72 hospitalized patients diagnosed with sepsis as the study population between March 2019 and March 2022.Among them,30 patients with sepsis and ARDS formed the study group,while 42 sepsis patients without ARDS comprised the control group.After diagnosis,venous blood samples were imme-diately collected from all patients.Flow cytometry was employed to analyze the expression of PMAs,platelet neutrophil aggregates(PNAs),and platelet aggregates(PLyAs)in the serum.Additionally,the Acute Physiology and Chronic Health Evaluation(APACHE)II score was calculated for each patient,and receiver operating characteristic curves were generated to assess diagnostic value.RESULTS The study found that the levels of PNAs and PLyAs in the serum of the study group were higher than those in the control group,but the difference was not statistically significant(P>0.05).However,the expression of PMAs in the serum of the study group was significantly upregulated(P<0.05)and positively correlated with the APACHE II score(r=0.671,P<0.05).When using PMAs as a diagnostic indicator,the area under the curve value was 0.957,indicating a high diagnostic value(P<0.05).Furthermore,the optimal cutoff value was 8.418%,with a diagnostic sensitivity of 0.819 and specificity of 0.947.CONCLUSION In summary,the serum levels of PMAs significantly increase in patients with sepsis and ARDS.Therefore,serum PMAs have the potential to become a new biomarker for clinically diagnosing sepsis complicated by ARDS.

Glanzmann Thrombasthenia: Managing Gingival Bleeding Triggered by Tooth Eruption—A Rare Case Report

Glanzmann thrombasthenia (GT) is a rare and often underdiagnosed congenital bleeding disorder caused by mutations in the genes encoding glycoproteins GPIIb or GPIIIa, resulting in platelet dysfunction. Inherited in an autosomal recessive manner, GT is characterized by the inability of platelets to aggregate. Clinically, it presents with mucocutaneous bleeding, such as easy and extensive bruising, severe epistaxis, menorrhagia, gingival bleeding, postpartum hemorrhage, and unexpected bleeding following procedures, despite a normal platelet count. We present a case involving a 6-year-old male patient who experienced spontaneous gingival bleeding for the past 4 weeks due to the eruption of his first permanent molars. The bleeding was particularly severe at night, disrupting the child’s sleep. The patient had been diagnosed with GT at the age of 16 months. Dental management was pursued, and the use of tranexamic acid mouthwash, combined with meticulous oral hygiene, resulted in an excellent response.

前列腺素E1对原发性肾病综合征作用初探(英文)

Objective:To investigate the effect of prostaglandin E1 (PGE1) (Alprostadii injection) on patients with primary nephrotic syndrome(PNS). Methods: 37 patients with PNS were recruited to study the effect of prostaglandin E1 on platelet aggregation function [ PAG (5,) PAG( m ) ], serum total protein (TP) , albumin (Al),blood urea nitrogen(BUN) ,serum creatinine(Scr) ,cholesterol(CHO), triglyceride(TG), protein in 24-hour urine (Pr/24h) and platelet account (PLT). Results: TP, Al, CHO, TG, BUN, Scr, Pr/24h, PAG(5) and PAG(m) in PNS group before treatment were significantly different from those in control group(P＜0.05, P＜0.01) while no significant difference was found for PLT. When treated with PGE1 , TP,Al,CHO, TG, Pr/24h, ADP- induced PAG(5) ,and Adr- induced PAG(5) and PAG(m) were significantly different from those before treatment (P＜0.05). Adr- induced PAG(5) and PAG(m) were significantly different. Adr- induced PAG(5) was xsitively correlated with BUN and Scr in PNS(P＜0.01). Similar correlation was found between ADP-induced PAG(5) and Al ,BUN,Scr,Pr/24h(P＜0.05), AD- induced PAG(m) and TP,CHO(P＜0.05). Conclusions: PGE1 may be an effective drug for the treatment for hypercoagulation in patients with PNS.

Effects of Berberine on TXB 2 and 6 Keto PGF 1α Plasma Levels in Rabbits with Uncomplete Cerebral Ischemia

Effects of berberine (Ber) on platelet aggregation and TXB2 and 6 keto PGF1a plasma levels were studied in rabbits with uncomplete cerebral ischemia. Ber inhibited uncomplete cerebral ischemic rabbit platelet aggregation triggered by collagen, ADP, and arachidonic acid (AA) with the IC 50 of 0.15, 0.46, and 0.51 mg·ml 1 , respectively. In rabbits, Ber 25, or 50 mg·kg 1 iv 30 min after uncomplete cerebral ischemia, restrained the collagen ADP and AA induced platelet aggregation determined 90 min later. With radioimmunoassay, we measured the thromboxane B2 (TXB 2) and 6 ketoprostaglandin F 1α (6 keto PGF 1α ) contents in rabbit plasma. The results indicated that the TXB 2 level in rabbit 120 min after uncomplete cerebral ischemia (921±539 pg·ml 1 ) was higher than that (230±71 pg·ml 1 ) in normal rabbits ( P < 0.01), but 6 keto PGF 1α level after ischemia (73±23pg·ml 1 ) was lower than that (262±988pg·ml 1 ) in normal rabbit. Ber (5, 25 or 50 mg·kg 1 ) reduced obviously the plasma TXB 2 level in rabbit with uncomplete cerebral ischemia (504±196, 386±174, or 272±183 vs 921±539 pg·ml 1 , respectively, P < 0.01). We conclude that the decrease of TXB 2 content is one of the possible mechanisms of Ber anti cerebral ischemic effect.

Sitagliptin in patients with non-alcoholic steatohepatitis: A randomized, placebo-controlled trial

AIMTo evaluate the effect of sitagliptin vs placebo on histologic and non-histologic parameters of non-alcoholic steatohepatitis (NASH).METHODSTwelve patients with biopsy-proven NASH were randomized to sitagliptin (100 mg daily) (n = 6) or placebo (n = 6) for 24 wk. The primary outcome was improvement in liver fibrosis after 24 wk. Secondary outcomes included evaluation of changes in NAFLD activity score (NAS), individual components of NAS (hepatocyte ballooning, lobular inflammation, and steatosis), glycemic control and insulin resistance [including measurements of glycated hemoglobin (HbA1C) and adipocytokines], lipid profile including free fatty acids, adipose distribution measured using magnetic resonance imaging (MRI), and thrombosis markers (platelet aggregation and plasminogen activator inhibitor 1 levels). We also sought to determine the correlation between changes in hepatic fat fraction (%) [as measured using the Iterative Decomposition of water and fat with Echo Asymmetry and Least-squares estimation (IDEAL) MRI technique] and changes in hepatic steatosis on liver biopsy.RESULTSSitagliptin was not significantly better than placebo at reducing liver fibrosis score as measured on liver biopsy (mean difference between sitagliptin and placebo arms, 0.40, P = 0.82). There were no significant improvements evident with the use of sitagliptin vs placebo for the secondary histologic outcomes of NAS total score as well as for the individual components of NAS. Compared to baseline, those patients who received sitagliptin demonstrated improved HbA1C (6.7% &#x000b1; 0.4% vs 7.9% &#x000b1; 1.0%, P = 0.02), and trended towards improved adiponectin levels (4.7 &#x000b1; 3.5 &#x003bc;g/mL vs 3.9 &#x000b1; 2.7 &#x003bc;g/mL, P = 0.06) and triglyceride levels (1.26 &#x000b1; 0.43 mmol/L vs 2.80 &#x000b1; 1.64 mmol/L, P = 0.08). However, when compared with placebo, sitagliptin did not cause a statistically significant improvement in HbA1C (mean difference, -0.7%, P = 0.19) nor triglyceride levels (mean difference -1.10 mmol/L, P = 0.19) but did trend towards improved adiponectin levels only (mean difference, 0.60 &#x003bc;g/mL, P = 0.095). No significant changes in anthropometrics, liver enzymes, other adipocytokines, lipid profile, thrombosis parameters, or adipose distribution were demonstrated. The MRI IDEAL procedure correlated well with steatosis scores obtained on liver biopsy in both groups at baseline and post-treatment, and the Spearman correlation coefficients ranged from r = 0.819 (baseline) to r = 0.878 (post-treatment), P = 0.002.CONCLUSIONSitagliptin does not improve fibrosis score or NAS after 24 wk of therapy. The MRI IDEAL technique may be useful for non-invasive measurement of hepatic steatosis.

Applying a highly specific and reproducible cDNA RDA method to clone garlic up-regulated genes in human gastric cancer cells

AIM: To develop and optimize cDNA representational difference analysis (cDNA RDA) method and to identify and clone garlic up-regulated genes in human gastric cancer (HGC) cells. METHODS: We performed cDNA RDA method by using abundant double-stranded cDNA messages provided by two self-constructed cDNA libraries (Allitridi-treated and paternal HGC cell line BGC823 cells cDNA libraries respectively). Bam H I and Xho I restriction sites harbored in the library vector were used to select representations. Northern and Slot blots analyses were employed to identify the obtained difference products. RESULTS: Fragments released from the cDNA library vector after restriction endonuclease digestion acted as good marker indicating the appropriate digestion degree for library DNA. Two novel expressed sequence tags (ESTs) and a recombinant gene were obtained. Slot blots result showed a 8-fold increase of glia-derived nexin/protease nexin 1 (GDN/PN1) gene expression level and 4-fold increase of hepatitis B virus x-interacting protein (XIP) mRNA level in BGC823 cells after Allitridi treatment for 72h. CONCLUSION: Elevated levels of GDN/PN1 and XIP mRNAs induced by Allitridi provide valuable molecular evidence for elucidating the garlic's efficacies against neurodegenerative and inflammatory diseases. Isolation of a recombinant gene and two novel ESTs further show cDNA RDA based on cDNA libraries to be a powerful method with high specificity and reproducibility in cloning differentially expressed genes.

Preservation of platelet function in patients with cirrhosis and thrombocytopenia undergoing esophageal variceal ligation

Background:Thrombocytopenia is a possible risk factor for bleeding after band ligation of esophageal varices.However,elevated von Willebrand factor(VWF)in cirrhosis improves platelet function and could decrease this risk.Our objective was to assess platelet function in patients with cirrhosis undergoing esophageal variceal ligation(EVL).Methods:The assessment consisted of platelet count,antigen and activity of VWF and VWF-cleaving protease ADAMTS-13 activity,and a platelet adhesion and aggregation test simulating vascular flow in vivo(Impact-RR)prior to EVL.Results:Totally 111 patients were divided into three groups according to platelet count:(1)<50×109/L(n=38,34.2%);(2)50×109/L to 100×109/L(n=47,42.3%);and(3)>100×109/L(n=26,23.4%).No statistically significant difference was found in the aggregate size of platelets[group 1:41.0(31.8–67.3)μm 2;group 2:47.0(33.8–71.3)μm 2;and group 3:47.0(34.0–66.0)μm 2;P=0.60]and no significant correlation was found between aggregate size and platelet count(Spearman r=0.07;P=0.47).Surface coverage was 4.1%(2.8%–6.7%),8.5%(4.0%–10.0%),and 9.0%(7.1%–12.0%)(P<0.001)in groups 1,2 and 3,respectively and correlated with platelet count(Spearman r=0.39;P<0.0001).There was no significant difference between groups in VWF or ADAMTS-13.Post-EVL bleeding occurred in six(5.4%)patients(n=2 in group 1,n=1 in group 2,and n=3 in group 3;P=0.32).Patients with bleeding had higher MELD scores[15.0(11.3–20.3)versus 12.0(10.0–15.0);P=0.025],but no difference was demonstrated for platelet function parameters.Conclusion:Platelet function is preserved even in the presence of thrombocytopenia,including in the patients with post-EVL bleeding.

Safety, Pharmacokinetic and Pharmacodynamic Studies of Batifiban Injection Following Single-and Multiple-Dose Administration to Healthy Chinese Subjects

Batifiban, a synthetic cyclic peptide, is a potent platelet glycoprotein GPⅡb/Ⅲa antagonist which may be useful in the treatment and prevention of acute coronary syndromes. The pharmacokinetics and pharmacodymanic （inhibition of platelet aggregation） effects, and tolerability of batifiban were investigated in healthy subjects following single bolus injection with doses of 55, 110, or 220 μg/kg, or multiple doses of an bolus followed intravenous infusion for 24 h （180 μg/kg plus 2.0 μg/minokg, and 220 μg/kg plus 2.5μg/minokg） in this phase I clinical trial. Plasma levels of batifiban and areas under the curve were found to be proportional to doses. Batifiban was rapidly eliminated with a half-life of approximately 2.5 h. Significant differences were noted for plasma levels of batifiban and areas under the curve between males and females. No significant differences in the terminal half-life were found between males and females. Batifiban reversibly inhibited ex vivo platelet aggregation in a dose- and concentration-dependent manner, consistent with its mechanism as a GPⅡ b/Ⅲa antagonist. Single and multiple intravenous doses of batifiban were found to be safe and well tolerated in healthy subjects. These results support a bolus injection plus intravenous infusion regimen of batifiban for the treatment and prevention of acute coronary syndromes.

Design and Synthesis of New Arylsulfonamide and Arylamide Derivatives for the Platelet Aggression Inhibitor

A series of arylsulfonamide and arylamide derivatives have been prepared from anisole in good yields. The structures of those compounds were confirmed by 1H-NMR and MS analysis. Their activities against platelet aggregation were tested in vitro by using the Born test on rabbits.

Hypoglycemic Activity of Jatrorrhizine

Summary： The hypoglycemic activity and its mechanism of Jatrorrhizine （Jat） were studied. The normal mice and alloxan-induced hyperglycemic mice were given with different doses of Jat. Blood glucose and liver glycogen levels were determined by spectrophotometry with glucose-oxidase and iodine reagents respectively. The levels of blood lactic acid （LC） and liver lactate dehydrogenase （LDH） activity were measured to explore the effect of Jat on anaerobic glycolysis. Succinate dehydrogenase （SDH） activity in liver was measured to evaluate the effect of Jat on aerobic glycolysis in liver. It was found that Jat （50 mg/kg, 100 mg/kg） could significantly decrease blood glucose level in a dose- and time-dependent manner in both normal and alloxan-diabetic mice, increase the activity of SDH, but had no significant effects on the LC level and LDH activity. Jat could significantly reduce the content of liver glycogen in normal mice. Moreover, Jat could inhibit the platelet aggregation in rabbits in vitro in a dose-effect relationship. It was concluded that Jat induced the pronounced decrease in blood glucose in normal and hyperglycemic mice. The hypoglycemic activity of Jat may be attributed to the enhancement of aerobic glycolysis.