Objective To observe the inhibition of amikacin in vitro on platelet aggregation and blood coagulation tests, and to study its effects on hemostasis and the related mechanisms.Methods Plateletrich plasma and platelet-poor plasma from donors were mixed with different concentration of amikacin, which was divided into four groups:0 mg/L, 30 mg/L, 91 mg/L and 910 mg/L group.The maximial ratio of platelet aggregation induced by ADP were measured with Platelet Aggregation Analyzer.The expression levels of P-selectin, GP Ⅱ b/Ⅲ a and Fg-R were determined with Flow Cytometer.The PT, APTT, TT and Fg of platelet-poor plasma were detected with Blood Coagulation Analyzer. The four concentration of amikacin mentioned above and two anticoagulants (62.5 U/ml of sodium heparin and 109 mmol/L of sodium citrate)were interacted with fresh whole blood, in which the blood CT and plasma Ca2+ were detected. Blood samples were collected from 10 patients with acute lower respiratory tract infection before and 30 minutes after routine amikcin treatment respectively.The maximial ratio of platelet aggregation, the expression levels of P-selectin, GPⅡ b/Ⅲa and Fg-R induced by ADP were measured; while PT, APTT, CT and plasma Ca2+ were determined.Results At 30 mg/L of amikacin group, the maximal ratios of platelet aggregation (65.8±3.9)%, the expression levels of P-selectin (9.2 ± 1.0)% and Fg-R (12.6 ± 1.7)% were statistically lower than those [(88.0 ±4.6%, (16.1 ± 1.3)% and (31.0 ±2.5)%]at 0 mg/L of amikacin group ( t = 9.442,8.432,9.993,P ＜ 0.01 ).At 30 mg/L of amikacin group, the APTT (80.5 ±6.8) s and CT ( 857 ± 66) s were significantly higher than those [(33.0 ± 3.6) s and (447 ± 35 ) s] at 0 mg/L of amikacin group ( t = 11.312, 13.211, P ＜ 0.01 ). There was a negative correlation between amikacin concentration and maximial ratio of platelet aggregation ( r = - 0.832, P ＜ 0.05 ), but a positive correlation between amikacin concentration and inhibitory rates of platelet aggregation ( r = 0.939, P ＜0.05) was observed, as well as APTT (r ＞0.870, P＜0.05).At 30 mg/L, 91 mg/L, and 910 mg/L of amikacin groups, the P-selectin and Fg-R expression were remarkably inhibited with a dose-dependent manner, the CT was notably enhanced [Fwithin subjects =21.44, 26.24, ( ＞29.81 ), P ＜0.01].At 0 mg/L,30 mg/L, 91 mg/L and 910 mg/L of amikacin groups, the PT values were ( 14.7 ± 1.9) s, ( 15.2 ± 1.7) s,(15.6±1.5) s and (22.1 ±2.1) s, respectively (F=8.21,P＜0.05), but there was no markeddifference for the levels of GP Ⅱ b/Ⅲ a, TT, Fg and plasma Ca2+ among the four groups ( P ＞ 0.05 ).After 30 minutes of amikacin treatment, the maximial ratio of platelet aggregation (51.6 ± 10.1)%, the expression levels of P-selectin (6.8 ± 1.8) % and Fg-R ( 20.1 ± 5.8 ) % were significantly lower than those [(66.8 ± 11.4)%, ( 10.9 ±3.1 )% and (28.5 ±7.4)%] before amikacin treatment, but APTT (49.8 ±5.9) s and CT (660 ±59) s were remarkably higher than those [(26.9 ±3.8) s and (410 ±45) s] before amikacin treatment, respectively ( t = 5.456,8.875,7.423,10.012,11.322, P ＜ 0.01 ), while the GP Ⅱ b/Ⅲ a expression, PT and Ca2+ concentration had no significant changes ( P ＞ 0.05).Conclusions There are inhibitory effects of amikacin on platelet aggregation mainly through the inhibition of both fibrinogen receptor activation and secretion reaction of activated platelet. Amikacin may also inhibit pathway of coagulation system factor to prevent blood coagulation.Therefore, risk of hemorrhage may be investigated in the patients with amikacin for anti-infection treatment.

Objective To investigate the effects of ZGDHu-1 on T lymphocytes activation in vitro to elucidate its immunosuppressive effects. Methods Lymphocytes isolated from healthy persons were stim-ulated with phytohanmagglutinin(PHA) and different experimental groups were set by cocultured for 24 h, 48 h with ZGDHu-1 or with ZGDHu-1 and Cyclosporin A(CSA). To assess the proliferation and apoptosis of T lymphocytes, we detected CD3~+ CD69~+ , CD3~+ CD25~+ , CD4~+ CD25~+ , CD8~+ CD25~+ and CD3~+ Fas~+, CD4~+ Fas~+ , CD8~+ Fas~+ with flow cytometry. The early apoptosis rate of lymphocytes was analyzed with flow cytometry. Culture supernatant IL-2 and TGF-β1 were detected with ELISA. Results ZGDHu-1 decreased PHA activative CD3~+ CD69~+, CD3~+ CD25~+, CD4~+ CD25~+ and CD3~+ Fas~+, CD4~+ Fas~+, Annexin V~+/ PI~- and inhibited IL-2 secretion and promoted TGF-β1 secretion respectively. ZGDHu-1 has synergistic effect with CSA to be more obvious. Conclusion ZGDHu-1 can inhibit T lymphocytes activation and de-creased apeptosis of T lymphocytes. ZGDHu-1 has synergistic effect with CSA to be obvious.

Objective To establish and assess the new method of APTT assay based on the combinations of Mg2+and Ca2+for lupus anticoagulants(LA)measurements.Methods This prospective study included 309 trisodium citrate anticoagulated plasma samples from 244 random patients and 65 patients with different autoimmune diseases(AID)to establish and assess the method of LA measurement, respectively.Final concentrations of 0,2.0, 4.0, 8.0,16.0 mmol/L Mg2+were added into 25 mmol/L Ca2+solution, and Actin reagent was used to measured plasma APTT of 94 patients.The applied concentration of Mg2+-Ca2+solution was confirmed through the special and significant alteration of APTT from LA-positive and -negative plasma observed in the presence of Mg 2+(test solution).Based on Actin reagent use,the test solution and 25 mmol/L Ca2+solution were applied to measure APTT of patients and normal individuals, respectively, and the ratio of Mg2+-Ca2+-APTT to Ca2+-APTT(Mg2+-Ca2+-APTT indices)and normalized Mg2+-Ca2+-APTT indices(NAR)were calculated, respectively.Mixed plasma NAR was measured,and CV%was calculated to evaluate the repeatability and stability of Mg 2+-Ca2+-APTT method.APTT of 150 patients was measured with the test solution and Actin reagent to calculate Mg 2+-Ca2+-APTT indices, and normalized LA ratio was determined with dRVVT method.The applicability of Mg2+-Ca2+-APTT assay was assessed through comparisons of the results from the two methods.Finally, NAR and NLR of 65 patients with AID(including 26 SLE patients)were measured with Mg2+-Ca2+-APTT assay and dRVVT method, respectively, and ROC curve was also used to assess the efficacy of the two methods for LA measurements.Results In all LA-negative plasma,APTT increased from 28.1 ±4.5 s to 61.2 ±7.9 s in normal APTT group,47.2 ±8.9 s to 97.5 ±10.3 s in increased APTT group,and 27.6 ± 5.1 s to 61.2 ±7.9 s in ACA-positive group when Mg2+increased from 0 to 8 mmol/L in Mg2+-Ca2+solution(F=34.12, 38.9 and 28.35,P<0.01).Following increased Mg2+concentration, APTT shortened from 0 to 4.0 mmol/L, but simultaneously prolonged from 4.0 to 16.0 mmol/L in LA-positive plasma with prolonged or normal APTT(F=31.55 and 39.51, P<0.01), and APTT was significantly higher in 8.0 mmol/L than that in 4.0 mmol/L(P<0.001).The test concentration of Mg 2+/Ca2+solution was 4.0 mmol/L.The within, inter-day CV% of NAR was 1.39%,2.30%, and 3.44%, respectively. According to the judging criteria of <0.966 and >1.034 of Mg2+/Ca2+indices, there was 141 patients with increased indices and NLR <1.20, and 9 patients with decreased ones and NLR≥1.20 in all 150 patients.The area under ROC curve of NAR and NLR for LA detection was 0.913(95%CI:0.848-0.978) and 0.892(95%CI:0.817-0.966), respectively, and the cut-off value was 0.87 and 1.13, respectively. The sensitivity and specificity of NAR(85% and 77%)was higher than that of NLR(81% and 74%), respectively.The accordant rate of positive,negative,and total results between NAR and NLR was 94.4%, 98.5%,and 98%,respectively.Conclusion The method of APTT assay based on Mg2+combining Ca2+for LA measurements is feasible,and can be used to detect plasma LA of patients.