RNA m6A modification facilitates DNA methylation during maize kernel development.

N6-methyladenosine (m6A) in mRNA and 5-methylcytosine (5mC) in DNA have critical functions for regulating gene expression and modulating plant growth and development. However, the interplay between m6A and 5mC is an elusive territory and remains unclear mechanistically in plants. We reported an occurrence of crosstalk between m6A and 5mC in maize (Zea mays) via the interaction between mRNA adenosine methylase (ZmMTA), the core component of the m6A methyltransferase complex, and decrease in DNA methylation 1 (ZmDDM1), a key chromatin-remodeling factor that regulates DNA methylation. Genes with m6A modification were coordinated with a much higher level of DNA methylation than genes without m6A modification. Dysfunction of ZmMTA caused severe arrest during maize embryogenesis and endosperm development, leading to a significant decrease in CHH methylation in the 5' region of m6A-modified genes. Instead, loss of function of ZmDDM1 had no noteworthy effects on ZmMTA-related activity. This study establishes a direct link between m6A and 5mC during maize kernel development and provides insights into the interplay between RNA modification and DNA methylation.

Decrease in DNA methylation 1 (DDM1) is required for the formation of m CHH islands in maize.

DNA methylation plays a crucial role in suppressing mobilization of transposable elements and regulation of gene expression. A number of studies have indicated that DNA methylation pathways and patterns exhibit distinct properties in different species, including Arabidopsis, rice, and maize. Here, we characterized the function of DDM1 in regulating genome-wide DNA methylation in maize. Two homologs of ZmDDM1 are abundantly expressed in the embryo and their simultaneous disruption caused embryo lethality with abnormalities in cell proliferation from the early stage of kernel development. We establish that ZmDDM1 is critical for DNA methylation, at CHG sites, and to a lesser extent at CG sites, in heterochromatic regions, and unexpectedly, it is required for the formation of m CHH islands. In addition, ZmDDM1 is indispensable for the presence of 24-nt siRNA, suggesting its involvement in the RdDM pathway. Our results provide novel insight into the role of ZmDDM1 in regulating the formation of m CHH islands, via the RdDM pathway maize, suggesting that, in comparison to Arabidopsis, maize may have adopted distinct mechanisms for regulating m CHH.

Efficient synthesis of Guanfu base G via highly regioselective lipase-catalyzed acylation in non-aqueous phase.

Lipase-catalyzed acylation of Guanfu alcohol-amine (GFAA) with vinyl acetate (VA) was performed in non-aqueous system for the preparation of Guanfu base G (GFG), a plant-originated alkaloid with significant antiarrhythmic activity. Among the eight lipases from different origins, Novozym 435 was found to be the best biocatalyst. The most suitable molecular sieve amount, substrate concentration, molar ratio of VA to GFAA, enzyme amount and reaction temperature were proved to be 40 mg/mL, 6 µmol/mL, 10:1, 2mg/mL and 50 °C, respectively. A maximum GFG yield of 37.4% was achieved under the selected conditions with methanol served as the optimal reaction medium. The structure of the acetylated product was elucidated by (1)H NMR and (13)C NMR analysis.

[Analysis of Relationship between Coagulation Function and Blood Transfusion in Patients with Emergency Rescue].

OBJECTIVE: Through researching preoperative coagulation function in the case of ABO-identical blood insufficient for emergency rescue transfusion according to recommended programs of special emergency rescue transfusion was carried out, the relationship between volume of blood products and coagulation function was analyzed. METHODS: The surgical cases of blood transfusion more than 1 600 ml during operation were collected in our hospitals from Aug 2015 to Dec 2016（n=218）, these cases were divided into the normal coagulation group（Group A） and abnormal coagulation group（Group B）, and the patients of emergency rescue transfusion O type blood group（Group C）. The basic information of cases, the infused volume of red blood cell（RBC）, virus-inactivated frozen plasma（VIFP）, fresh frozen plasma（FFP）, cryoprecipitate（C）and platelets（P）, prothrombin time（PT）, activated partial thromboplastin time（APTT）, fibrinogen（FIB）and international normalized ratio（INR）were analyzed, the relationship between volume of blood transfusion and coagulation function were also analysed. At the same time, the efficiency and safety index were compared before and after transfusion. These indexes, such as hemoglobin（Hb）, indirect bilirubin（IBiL）, direct antiglobulin test（DAT）and irregular antibody were determined at the time-paints of 24 h, 3 d and 7 d after blood transfusion. RESULTS: The differences of age and blood type between group A and B was not statistically significant（P>0.05）. Proportion of A and AB type，transfusion volume of RBC, FFP, C and Plt all were significantly higher in group C （P<0.05）. PT, APTT, FIB and INR in group B and C were significantly different（P<0.05）, which related with the transfusion volume of RBC, FFP and C（P<0.05）. DAT and irregular antibody in every group was all negative before transfusion, No any new irregular antibodies had been detected after transfusion. Hb after blood transfusion was not statistically different before and after transfusion in group C, the IBiL level also was not significantly increased after blood transfusion（P > 0.05）. All those showed that emergency rescue transfusion was safe and effective. CONCLUSION: Preoperative coagulation function is one of factors inflnencing blood products transfusion volume during operation, which also is the basis for evaluating bleeding and blood transfusion. Emergency O type blood and ABO-matched blood transfusions show the same efficiency and safety.

[Efficacy of intravenous Acehytisine Hydrochloride versus propafenone on terminating paroxysmal supraventricular tachycardia: a double-blinded, randomized multi-center study].

OBJECTIVE: In this double-blinded, randomized, parallel study, we investigated the clinical efficacy of intravenous Acehytisine Hydrochloride (AHH) and propafenone on terminating paroxysmal supraventricular tachycardia (PSVT). METHODS: Patients (18 - 70 years old) with either spontaneous or induced sustained supraventricular tachycardia lasted at least 15 min were recruited in this study. Exclusion criteria included sick sinus syndrome, atrial ventricular block or intraventricular block, etc. Eligible patients were randomly assigned to receive intravenously AHH (n=101) or propafenone (n=100) according to a proportion of 1:1 in a double-blinded manner. AHH (4 mg/kg, iv.) or propafenone (PRO, 1 mg/kg, iv.) was administered in 5 min followed by the same dose if no response was observed. Conversion times, vital signs, electrocardiograms were documented before and after drug administration. RESULTS: Except for age, the demographic characteristics and clinical features were comparable between the two groups. Efficacy on PSVT termination was comparable between AHH (72/101, 71.3%) and PRO group (73/100, 73.0%, P=0.6368). The average time from drug administration to conversion was also similar [AHH: (9.62 +/- 8.39) min vs. PRO: (10.61 +/- 9.47) min, P=0.5035]. In the AHH group, 59/72 episodes of PSVT were terminated by the first dose, and 66/72 were terminated prematurely. The average AHH dose in the 72 converted patients was (273.7 +/- 111.2) mg. In the PRO group, 54/73 episodes of PSVT were terminated by the first dose. The electrocardiographic parameters, such as sinus recovery time, longest PP and RR interval, PR interval, QRS interval, QT interval after conversion were similar between the two groups. Transient adverse events were reported in 11/101 (10.9%) patients in the AHH group and in 18/100 (18.0%,) in the PRO group (P=0.1653). CONCLUSION: With the dosage used in the present study, the efficacy on terminating PSVT was comparable between AHH and PRO.

[Experimental Study on Neonatal ABO or RhD Compatible Blood Transfusion].

OBJECTIVE: To investigate the safety and effectiveness of neonatal ABO or Rh(D) by using compatible blood transfusion through retrospective analysis of data from cases received compatible blood transfusion and type matched blood transfusion. METHODS: The clinical data of 26 cases of neonatal compatible blood transfusion in Chinese Nanchang area from January 2014 to October 2016 were collected, and 26 cases of neonatal type-matched blood transfusion were selected according to ratio of 1:1 cases. The efficiency and safety index of 26 patients compatible blood transfusion were compared with that of type-matched blood transfusion. The efficiency indexes included: patients' basic characteristics, red blood cell (RBC) count, hemoglobin (Hb) level, hematocrit (Hct), and the safety indexes contain Hb level and indirect bilirubin (IBiL) value before and after blood transfusion, irregular antibody screening, direct antiglobulin test (DAT) results and the adverse reactions of blood transfusion. RESULTS: The age, sex, days of hospitalization between compatible blood transfusion and type matched blood transfusion were not statistically significantly different (P>0.05). The Hb level before transfusion, blood transfusion volume and the increase of Hb, Hct and RBC were not statistically significantly different between two groups (P>0.05). The values of Hb, Hct and RBC in 2 groups significantly increased at the day 1 after blood transfusion (P<0.05). No blood transfusion adverse reaction occurred in 2 groups. The IBiL value significantly decreased in compatible blood transfusion patients at the day 1 after blood transfusion (P<0.05). No new irregular antibodies had been detected after transfusion in all patients, and the others' DAT and screening for irregular antibodies were negative except 22 patients with neonatal hemolysis. The values of Hb and IBiL statistically significantly differenence were not in 12 patients between 1d, 3d, 7d after blood transfusion (P>0.05). CONCLUSION: The efficiency and safety between compatible blood transfusion and type matched blood transfusion are the same in neonatal blood transfusion. Compatible blood transfusion is a safe and effective in clinical blood transfusion.

[Isolation and identification of hetisine-type alkaloids from Aconitum coreanum by high speed countercurrent chromatography].

AIM: To search for more bioactive compounds from the roots of Aconitum coreanum (Lèvl.) Rapaics. METHODS: High speed countercurrent chromatography was successfully applied to the separation of alkaloids from Aconitum coreanum. The structures were elucidated by their physicochemical properties and spectroscopic analysis. RESULTS: Two-phase solvent system composed of CHCl3-CH3OH-0.2 mol x L(-1) HCl (10:3:3, volume ratio) was used in this experiment, eight alkaloids were obtained from the roots of Aconitum coreanum, which were identified as: 2alpha-propionyl-11alpha,13beta-diacetyl-14-hydroxyhetisine (I), Guanfu base P (II), Guanfu base G (III), Guanfu base F (IV), Guanfu base Z (V), Guanfu base O (VI), Guanfu base A (VII), Guanfu base B (VIII). CONCLUSION: Compound I is a new alkaloid, named Guanfu base R.

[Effect of Guanfu Base A in patients with ventricular arrhythmias].

OBJECTIVE: To investigate the effect and safety of intravenous Guanfu Base A hydrochloride (GFA) in the treatment of ventricular arrhythmias. METHODS: Patients without severe structural heart disease presenting with equal or more than 150 premature ventricular contractions per hour and/or non sustained ventricular tachycardia in drug-free holter monitoring were recruited in this double blind randomized active-controlled study. Eligible patients were randomly assigned to receive GFA or propafenone intravenously by a proportion of 1:1 in a double-blind manner. Intravenous bolus of the study medicine was given, followed by maintenance infusion for 6 hours. 24 hours continuous electrocardiographic recordings were performed to evaluate the efficacy. Vital signs, electrocardiograms and adverse events were documented before, during and after drug administration. RESULTS: A total of 201 patients came from eight centres were randomized to GFA or propafenone group. The demographic characteristics, the extent of ventricular arrhythmias and baseline clinical findings were comparable between the two groups. There were no significant differences in the percentage of reducing premature ventricular contractions and the accumulated efficacy between two groups. GFA had tendency to be more effective than propafenone in reducing the number of ventricular ectopy (P = 0.0609). There were no significant differences in the onset of action after drug administration between two drugs. The tolerance of GFA was better than propafenone. The adverse events in GFA group were less severe than those in propafenone group. CONCLUSIONS: Intravenous GFA in controlling the premature ventricular contraction has comparable effect to IV propafenone. Tolerance of GFA was better than propafenone.

[Key Preparation Technique and Clinical Application of Frozen Platelets].

OBJECTIVE: To explore the key technique for preparation of the frozen platelet and efficacy of its clinical application. METHODS: The influences of the donators' peripheral platelet count, starting time of freeze, injection rate and evenness of the freeze-protective agent, storage mode, re-melting temperature and the capacity of water-bath etc. on the quality of the frozen platelets were analyzed retrospectively in 3 257 samples of frozen platelets before platelet pheresis. Then, the platelet counts were examined in 150 cases transfused with frozen platelets at the time-points of 1, 24, 48 and 72 hrs after transfusion, 90 cases suffered from the obstetrical bleeding were transfused with 200 parts of the re-melting frozen platelets, and then the peripheral blood platelet count, platelet increasing index(CCI), bleeding time and blood clot retraction rate etc. were observed for determining the clinical efficiency of the frozen platelets. RESULTS: The floccule in the re-melting frozen platelets from the donators with (175-250)×10(9)/L platelets were decreased significantly(P<0.01). The quality of frozen platelets was influenced by the following factors, such as injection of DMSO at a too fast and heterogeneous rate, blood bags stored in a multilamminar space, and re-melting in a water-bath of small capacity etc. The routine storage for 0 and 3 days did not influence the quality of the frozen platelets. The recovery rate of one year-freezing platelets all was higher than 80%. The effects of the frozen platelets transfused into the patients with obstetrical bleeding displayed good haemostatic results, and the blood transfusion reaction did not occur. However, the frozen platelets immediately were exhausted and displayed their function, but the counting after 48 hrs could not display a good effect of raising platelet number. CONCLUSIONS: The peripheral platelet count before platelet pheresis, the injection rate and evenness of the protective agent, the number of stratum for blood bags and the capacity of re-melting water-bath etc. all are the key factors influencing the quality of the frozen platelets. The frozen platelets prepared in this study shows a good efficacy of clinical application.

[A new hetisine-type alkaloid from the stems and leaves of Aconitum coreanum].

AIM: To study the chemical constituents of the stems and leaves of Aconitum coreanum (Lèvl.) Rapaics. METHODS: The constituents of Aconitum coreanum were isolated by using various kinds of modern chromatographic methods. The new alkaloid was identified on the basis of spectral analysis. RESULTS: Two compounds were isolated and identified as: 13-dehydro-1beta-acetyl-2alpha,6beta-dihydroxyhetisine (I) and Guanfu base G (II). CONCLUSION: Compound I is a new alkaloid.

Antiarrhythmic ionic mechanism of Guanfu base A--Selective inhibition of late sodium current in isolated ventricular myocytes from guinea pigs.

The present study was designed to determine the effects of Guanfu base A (GFA) on the late sodium current (INa.L), transient sodium current (INa.T), HERG current (IHERG), and Kv1.5 current (IKv1.5). The values of INa.L, INa.T, IHERG and IKv1.5 were recorded using the whole-cell patch clamp technique. Compared with other channels, GFA showed selective blocking activity in late sodium channel. It inhibited INa.L in a concentration-dependent manner with an IC50 of (1.57 ± 0.14) µmol · L(-1), which was significantly lower than its IC50 values of (21.17 ± 4.51) µmol · L(-1) for the INa.T. The inhibitory effect of GFA on INa,L was not affected by 200 µmol · L(-1) H2O2. It inhibited IHERG with an IC50 of (273 ± 34) µmol · L(-1) and has slight blocking effect on IKv1.5, decreasing IKv1.5 by only 20.6% at 200 µmol · L(-1). In summary, GFA inhibited INa.L selectively and remained similar inhibition in presence of reactive oxygen species. These findings may suggest a novel molecular mechanism for the potential clinical application of GFA in the treatment of cardiovascular disorders.

[Determination of guanfu base A hydrochloride in plasma by LC-MS method and its pharmacokinetics in dogs].

AIM: To establish an analytical method for determination of guanfu base A (GFA) concentration in plasma and to study its pharmacokinetic profile in dogs. METHODS: Six dogs were given a 7.56 mg.kg-1 dose intravenously. Blood samples were collected at various time-points after drug administration. Analytical method based on liquid chromatography-mass spectrometry (LC-MS) was established to determine the plasma concentration of GFA. Pharmacokinetic evaluation was carried out using the 3P87 program. RESULTS: The calibration curves were linear over the concentration range from 0.42 microgram.mL-1 to 21.2 micrograms.mL-1 (gamma = 0.9994). The intra-day and inter-day precisions were generally good (< 15%) at low, medium and high concentrations. The overall recovery of the analytes was more than 80%. Six dogs were given an i.v. dose of 7.56 mg.kg-1 of GFA hydrochloride, an open three compartment model best described the concentration-time profiles for GFA. The half-lives for the rapid and slow distribution phase and terminal elimination phase (T1/2 pi, T1/2 alpha and T1/2 beta) were 0.07 h, 1.5 h, and 13.5 h, respectively. The total area under the plasma concentration-time curve (AUC), the volume of the central compartment (Vc), and plasma clearance (CLs) were 61.43 micrograms.h.mL-1, 0.37 L.kg-1 and 0.14 L.kg-1.h-1, respectively. CONCLUSION: The analytical method was shown to be sensitive, specific, rapid and reproducible, and was suitable for pharmacokinetic studies of GFA.

[Study on the metabolites of guanfu base A hydrochloride in rat urine by high performance liquid chromatograph-mass spectrum].

AIM: To study the metabolites of guanfu base A hydrochloride (GFA) in rat urine. METHODS: Rat urine was collected after i.v. injection of GFA. Phase I metabolites were identified by HPLC/MS and by comparison with authentic standards. Phase II conjugates were treated with either glucuronidase or sulfatase in presence or absence of glucuronidase specific inhibitor D-saccharic acid beta-1,4-lactone. The aglycones were identified by HPLC/MS. RESULTS: Phase I metabolites guanfu base I (GFI) and guanfu alcohol-amine (AA) were separated and identified in rat urine by comparison with authentic standards. Phase II conjugates, for which no authentic standards were available, GFA glucuronide and sulfate conjugates, GFI glucuronide and sulfate were separated and tentatively identified by hydrolysis with glucuronidase or sulfatase, the aglycones, GFA and GFI, were identified in rat urine. CONCLUSION: After i.v. injection of GFA, GFA is metabolized into GFI, AA, GFA glucuronide and sulfate conjugates, GFI glucuronide and sulfate conjugates in rat urine. The polarity of the metabolites is increased, and the effectiveness of them is lower than the parent drug.

New diterpenoid alkaloids from Aconitum coreanum and their anti-arrhythmic effects on cardiac sodium current.

Two new diterpenoid alkaloids, Guan-Fu base J (GFJ, 1) and Guan-Fu base N (GFN, 2) along with nineteen known alkaloids (3-21) were isolated from the roots of Aconitum coreanum (Lèvl.) Rapaics, which is the raw material of a new approval anti-arrhythmia drug "Acehytisine Hydrochloride". The structures of isolated compounds were established by means of 1D, 2D NMR spectroscopic and chemical methods. All isolates obtained in the present study were evaluated for their inhibitory effects on blocking the ventricular specific sodium current using a whole-cell patch voltage-clamp technique. Among these 21 compounds, Guan-Fu base S (GFS, 3) showed the strongest inhibitory effect with an IC50 value of 3.48 µM, and only hetisine-type C20 diterpenoid alkaloids showed promising IC50 values for further development.

[Influence of S-nitrosoglutathione on the membrane glycoprotein of frozen platelets].

This study was purposed to explore the influence of S-nitrosoglutathione (GSNO) on membrane glycoprotein of frozen platelet. The levels of membrane glycoprotein on fresh liquid platelets, frozen platelets and frozen platelets with GSNO were measured by flow cytometry. The results showed that the GSNO obviously decreased platelet aggregation, the PAC-1 change in the three groups was not significant. The changes of CD42b and CD62P in fresh liquid platelet group, frozen platelet group and frozen platelets with GSNO were significant different. The change of membrane glycoprotein in above-mentioned three group was not significant. It is concluded that the GSNO inhibits platelet aggregation, maintains the function of platelets and may be used as a cryoprotectant. When frozen platelets were added with GSNO, the molecular rearrangement, structure change and other mechanism may occur in platelets.

[Recent research advances on cryopreserved platelets].

The right choice of frozen protective agents and additives is an important factor to ensure the quality of frozen platelets. The immediate hemostatic function of frozen platelet in vivo is superior to liquid-stored platelets. In order to ensure the quality of frozen platelets better, it is important to understand the role of dimethylsulfoxide (DMSO) in the preservation of frozen platelets and its mechanism, and to understand the mechanism of DMSO enhancing the hemostatic function of frozen platelets and the effects of different factors on the frozen platelets. In this review, the long-term preservation of frozen platelets and its quality standards, the mechanism of DMSO effect on the molecular changes and inhibition of frozen platelets, different factors influencing preservation freezing platelets and the test of preservation effects, the application of frozen platelets to the military operation and disaster relief, the canine frozen platelet studies and so on are summarized.

[Influence of S-nitrosoglutathione on agglutination and nitric oxide concentration in frozen platelets].

The aim of this study was to investigate the influence of S-nitrosoglutathione (GSNO) on agglutination and nitric oxide (NO) concentration in frozen platelets. The agglutination of platelets was detected by using platelet agglutination apparatus, the level of NO in platelets was detected by the nitrate enzyme reduction method. The results showed that the rates of agglutination in freeze platelets and frozen platelets treated with GSNO were (35.47 ± 2.93) and (24.43 ± 3.07), which were significantly lower than that in fresh liquid platelets (63.44 ± 2.96). The level of NO concentration in frozen platelets was (22.16 ± 6.38), which was significantly lower than that in fresh liquid platelets (31.59 ± 16.88). The level of NO concentration in frozen platelets treated with GSNO was (45.64 ± 6.31), which was significantly higher than that in fresh liquid platelets (P < 0.01). It is concluded that GSNO increases the concentration of NO in frozen platelets, inhibits platelet activation and maintains platelet function, thus GSNO can be used as a frozen protective agent.

[Effect of trehalose-loading on red blood cell membrane].

This study was purposed to evaluate the effect of trehalose-loading on physiological and biochemistry properties of red blood cell (RBC) membrane. The samples were divided into the control group (RBC without trehalose loading) and the test group (RBC with trehalose loading). Osmotic fragility reaction was used to determine the osmotic fragility change of loaded RBC membrane in NaCl solution of different osmotic concentration. Flow cytometry and deformeter were used to assay the integrality and deformability of the RBC, respectively. The results showed that the NaCl solution osmotic concentrations were 160 mOsm and 121.4 mOsm, respectively when the haemolysis rate was 50% of the control group and the test group. Flow cytometry data demonstrated that incubation of RBC in a hypertonic trehalose solution resulted in a fraction of cells with different complexity that attached to little Annexin V-FITC, and that it could be removed by washing and resuspending the RBC in an iso-osmotic (300 mOsm PBS) medium. The deformability of the loaded RBC descend, the statistical difference was significant between control and test groups (P < 0.01). It is concluded that the membrane physiological and biochemistry stability and membrane integrality of RBC in a hyper osmotic pressure can be retained after trehalose loading.

[Optimization of lyophilization procedures for freeze-drying of human red blood cells].

OBJECTIVE: To investigate the different parameters of the lyophilization procedures that affect the recovery of the rehydrated red blood cells (RBCs). METHODS: Human RBCs loaded in tubes were cooled with 4 different modes and subjected to water bath at 25 degrees celsius;. The morphological changes of the RBCs were observed to assess the degree of vitrification, and the specimens were placed in the freeze-dryer with the temperature set up at 40, -50, -60, -70 and -80 degrees celsius;. The rates of temperature rise of the main and secondary drying in the lyophilization procedures were compared, and the water residue in the specimens was determined. RESULTS: The protectant did not show ice crystal in the course of freezing and thawing. No significant difference was found in the recovery rate of the rehydrated RBCs freeze-dried at the minimum temperature of -70 degrees celsius; and -80 degrees celsius; (P > 0.05). The E procedure resulted in the maximum recovery of the RBCs (83.14% ± 9.55%) and Hb (85.33% ± 11.42%), showing significant differences from the other groups(P < 0.01 or 0.05). The recovery of the RBCs showed a positive correlation to the water residue in the samples. CONCLUSION: Fast cooling in liquid nitrogen and shelf precooling at -70 degrees celsius; with a moderate rate of temperature rise in lyophylization and a start dry temperature close to the shelf equilibrium temperature produce optimal freeze-drying result of human RBCs.

[Optimization of composition and concentration for lyophlizing protectant of human red blood cells].

This study was purposed to investigate the effect of different compositions and concentrations of lyophilizing protectants on recovery of RBCs and hemoglobin (Hb) after rehydration of lyophilized RBCs. The RBC lyophilizing protectants composed of a series concentrations of PVP, trehalose and different osmotic protectants were applied for protecting lyophilizing process of RBCs, the recovery of RBCs and Hb after rehydration of lyophilized RBCs was detected. The results showed that there were significant differences in loss ratio of RBCs between protectants composed of different compositions and concentrations (p<0.05 or p<0.01). The loss ratio of RBCs in protectant containing 30% PVP40, 150 mmol/L trehalose and 2% BSA was minimum (0.02%), the loss ratio of RBCs in protectant containing 6% PVP 360, 100 mmol/L trehalose and 2% BSA was maximum (0.27%). The difference of effect between 150 and 50 mmol/L trehalose was statistically significant (p<0.01). The recovery rates of RBCs and Hb in protectants contained PVP40 of different concentrations were different after rehydration of lyophilized RBCs. The protectant containing 15% PVP40, 150 mmol/L trehalose and 2% BSA showed optimal protective efficacy for lyophilized RBCs, the recovery rates of RBCs and Hb were 61.29+/-4.11% and 62.49+/-5.91% respectively, which were statistically different from other protectants (p<0.01). The protectants containing glycerol displayed best efficiency in lyophilization too, the recovery rates of RBCs and Hb were 65.97+/-4.52% and 67.24+/-5.94%, respectively. It is concluded that the protectants composed of 0.8 mol/L glycerol, 15% PVP40, 150 mmol/L trehalose and 2% BSA (pH 7.3 ) may be used as the protectant lyophilizing human RBCs in future study.