Effect of meridian sinew releasing technique on moxibustion sensation of heat-sensitive moxibustion in patients with knee osteoarthritis / 中国针灸

OBJECTIVE@#To observe the effect of meridian sinew releasing technique on moxibustion sensation of heat-sensitive moxibustion in patients with knee osteoarthritis (KOA).@*METHODS@#A total of 60 patients with KOA were randomly divided into an observation group and a control group, 30 cases each group. In the observation group, on the basis of the meridian sinew releasing technique, moxibustion sensation exploration method was applied at Dubi (ST 35) area on the affected side. In the control group, moxibustion sensation exploration method was applied at Dubi (ST 35) area on the affected side. The meridian sinew releasing technique was performed for 20 min each time, the moxibustion sensation exploration method was performed for 60 min each time, once a day for 3 days. The excitation rate, latency, duration time and intensity value of moxibustion sensation of heat-sensitive moxibustion were recorded on the 1st, 2nd and 3rd days of exploration in the two groups.@*RESULTS@#The excitation rate on the 3rd day of exploration and total excitation rate in the observation group were higher than the control group (P<0.05). On the 1st, 2nd and 3rd days of exploration, the latency of moxibustion sensation of heat-sensitive moxibustion in the observation group was shorter than the control group (P<0.05), the duration time was longer than the control group (P<0.05), and the intensity value was higher than the control group (P<0.05).@*CONCLUSION@#Meridian sinew releasing technique could improve the excitation rate of moxibustion sensation of heat-sensitive moxibustion in patients with KOA, shorten the latency, prolong the duration time, and improve the intensity value.

Optimization of lyophilization procedures for freeze-drying of human red blood cells / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the different parameters of the lyophilization procedures that affect the recovery of the rehydrated red blood cells (RBCs).</p><p><b>METHODS</b>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.</p><p><b>RESULTS</b>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.</p><p><b>CONCLUSION</b>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.</p>

Optimization of composition and concentration for lyophlizing protectant of human red blood cells / 中国实验血液学杂志

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.

Preliminary study on rehydrated conditions for lyophilized human red blood cells / 中国实验血液学杂志

The objective of this study was to investigate the effect of different rehydration conditions on recovery of the lyophilized red blood cells (RBC) so as to optimize the RBC rehydration. The different conditions, including different rehydration solution, the rehydration temperature, volume change rate of the lyophilized RBC rehydrated by the vapor firstly, were studied, the recovery rate and change of physiological and biochemical properties of the rehydrated RBC were detected. The results indicated that the solution of 10% (w/v) PVP40 in PBS showed the best effect, and the RBC recovery rate increased with increasing of rehydration temperature, and the optimal temperature of rehydration was at 37 degrees C. Pre-rehydration in condition of vapor could raise the RBC recovery rate, and promote the MCV and RDW to close to index of the fresh RBC, the deformability of the rehydrated RBC was no serious as compared with RBC preserved in conventional condition, but the activity level of ATP, G-6-PD, SOD, 2, 3-DPG of the rehydrated RBC less decreased. It is concluded that the optimal rehydration conditions for lyophilized RBC are pre-rehydration in the 37 degrees C with vapor firstly, PBS + 10% (w/v) PVP40 rehydration solution and rehydration temperature at 37 degrees C, but the protection of RBC membrane needs to be furtherly studied.

Cryopreservation strengthens procoagulative activities of platelets / 中国实验血液学杂志

The aim of this study was to explore the potential relationship between the enhancement of instant hemostatic function in vivo of cryopreserved platelets and its procoagulative related molecule activities. The ability of platelet binding factor V density of GPIb-IX-V (CD42a) at platelet member surface were detected by flow cytometry, the clotting time induced by activated platelets were evaluated by coagulometer and platelet count, MPV and PDW were measured by hemocytometer before and after fresh platelets were cryopreserved. The results showed that the clotting time induced by activated cryopreserved platelets decreased by 43.9%, even quicker than that induced by fresh platelets; the fluorescence intensity of cryopreserved platelet binding factor V increased by 117%, more than that of fresh platelets binding factor V; the GPIb-IX-V (CD42a) density at cryopreserved platelet membrane surface increased by 32%, higher than that at fresh platelet surface. It is concluded that the enhancement of instant hemostatic function in vivo of cryopreserved platelet may be related to higher expression of procoagulative molecules or to their enhanced activity and rapid hemostatic effect.

Inhibition of L-arginine and cilostazol on activation of platelets in vitro / 中国实验血液学杂志

The purpose of study was to investigate the effects of L-arginine and cilostazol on platelet-activation and aggregation reserve in vitro, so as to provide proof for selecting reversible activation-inhibitors for platelets lyophilization. Activation and function of platelets were investigated by using flow cytometry with the CD62p and PAC-1 expression and re-expression after being activated by thrombin, and by means of platelet aggregation reaction to thrombin, ADP and propyl gallate, as well as coagulation activity of platelets. The results showed that expression of CD62p and PAC-1 increased after being pretreated. Both L-arginie and cilostazol could inhibit CD62p and PAC-1 expression and related with their concentrations. Cilostazol had an intensive inhibition effect on expressions of CD62p and PAC-1 induced by thrombin, and the inhibition increased when concentration augmented. L-arginine had the same effects on PAC-1, but had no effects on CD62p. L-arginine and cilostazol inhibited aggregation induced by thrombin, ADP and propyl gallate, and the inhibitions were related directly with dosage. When L-arginine concentration was higher or equal to 15 mmol/L, or cilostazol concentration was in range of 1 - 4 mmol/L, the aggregation time were prolonged so much or even no aggregation. It is concluded that when L-Arginine concentration is 5 mmol/L and 10 mmol/L, platelet activation can be inhibited, but aggregation ability and characters keep intact. Concentration at 5 mmol/L may be the best. 1 mmol/L of cilostazol can inhibit activation in vitro and retain part of platelet ability of aggregation and reexpression.

Experimental study on lyophilization of platelets / 中国实验血液学杂志

The aim of this study was to search a procedure of platelet lyophilization and find a way of long-term storage of human platelets at normal temperature with smaller size and lighter weight, to be convenient to transport at long distance thus to meet the demands in accidents and war time. Human platelets were pretreated by freezing, the first and the second desiccation, and were added with reversible activation-inhibitors of platelets, DMSO and trehalose, then were rehydrated. At the same time, the recovery rate of platelets, platelet maximal aggregation induced by thrombin, coagulation of platelets, CD62p expression and PAC-1 expression were assayed. The results indicated that the recovery rate of the platelets was 56.29%. The platelet maximal aggregation induced by thrombin had no significant difference between lyophilized platelets and the fresh platelet-rich plasma (FPRP), but the aggregation of platelets induced by ADP or propyl gallate was decreased by 49.34% and 26.25%. Coagulation of the lyophilized platelets was not significantly different from FPRP. CD62p expression of the lyophilized platelets (42.36%) was higher than that in FPRP while PAC-1 expression was 2.12%. CD62p re-expression rate induced by thrombin was 50.88% and PAC-1 re-expression was 54.55%. It is concluded that the ability of recovered lyophilized platelets added with reversible activation-inhibitors, DMSO and trehalose to aggregate and coagulate has showed no significant difference as compared with FPRP. The reversible activation-inhibitors can decrease CD62p expression of lyophilized platelets, and may enhance their survival ability and prolongate survival time. Therefore the efficiency of lyophilizing platelets can be improved based on this freeze-drying procedure.

Protective effects of DMSO on function of lyophilized human platelets / 中国实验血液学杂志

This study was aimed to investigate the effects of DMSO on platelets during pre-treatment for lyophilization, including centrifugation, washing and loading trehalose. After pre-treatment for lyophilization, the expression of platelet membrane surface glycoprotein (GP) including CD62p and PAC-1 was analyzed by FCM before and after induction with thrombin, the mean platelet volume (MPV) and platelet maximal aggregation with several platelet inducers were investigated. The results showed that the expression rates of CD62p and PAC-1, as the platelet activation signs, increased and were 30.37% and 15.01% respectively in group without DMSO after pre-treatment. And their differences in comparison with control were statistically significant, but that of CD62p was 10.72% and PAC was 10.11% in group with DMSO, in comparison with group without DMSO respectively, their differences were statistically significant after diluting with DMSO, CD62p was re-expressed to 54.39% in group with DMSO and more than that in group without DMSO and lower than control statistically significant. PAC-1 was re-expressed to 49.28% in group with DMSO and more than that in group without DMSO (p<0.01) and reached to control. Platelet maximal aggregations induced by thrombin, restocetin and propyl gallate were 92.76%, 91.24% and 89.66 respectively in group with DMSO. These were closed to that in control group and in group without DMSO. But the aggregation induced by ADP was 34.33%, it was less than control (p<0.01) and more than that in group without DMSO (p<0.01). It is concluded that DMSO can inhibit the expression of CD62p and PAC-1 on platelet in vitro. But when diluted with plasma, platelets can express CD62p and PAC-1 induced by thrombin and be led to aggregate by several inducers, so the inhibitory effects of DMSO on platelet activation are reversible. DMSO play roles in inhibitor damage from platelet activation and cryoprotectant. This property of DMSO is very important in research of platelets lyophilization.

Optimization of trehalose loading in red blood cells before freeze-drying / 中国实验血液学杂志

The key points for better protection of trehalose in freeze-drying red blood cells (RBCs) are to resolve non-osmosis of trehalose to red blood cells and to make cytoplasmic trehalose to reach effective concentration. This study was aimed to investigate the regularity of loading RBCs with trehalose, screen out optimal loading condition and evaluate the effect of trehalose on physico-chemical parameters of RBCs during the period of loading. The cytoplasmic trehalose concentration in red blood cells, free hemoglobin and ATP level were determined at different incubation temperatures (4, 22 and 37 degrees C), different trehaolse concentrations (0, 200, 400, 600, 800 and 1000 mmol/L) and different incubation times (2, 4, 6, 8 and 10 hours), the cytoplasmic trehalose, free hemoglobin (FHb), hemoglobin (Hb) and mean corpuscular volume (MCV) in fresh RBCs and RBCs stored for 72 hours at 4 degrees C were compared, when loading condition was ensured. The results showed that with increase of incubation temperature, time and extracellular trehalose concentration, the loading of trehalose in RBCs also increased. Under the optimal loading condition, cytoplasmic trehalose concentration and free hemoglobin level of fresh RBCs and RBCs stored for 72 hours at 4 degrees C were 65.505 +/- 6.314 mmol/L, 66.2 +/- 5.002 mmol/L and 6.567 +/- 2.568 g/L, 16.168 +/- 3.922 g/L respectively. It is concluded that the most optimal condition of loading trehalose is that fresh RBCs incubate in 800 mmol/L trehalose solution for 8 hours at 37 degrees C. This condition can result in a efficient cytoplasmic trehalose concentration. The study provides an important basis for long-term preservation of RBCs.

Process of human platelets loaded with rehalose before lyophilization / 中国实验血液学杂志

The aim of this research was to study the technology and methods of loading lyoprotectant-trehalose into cytoplasm of human platelets before lyophilization, to optimize experimental conditions of loading trehalose, to investigate the changes of platelets response to agonists and activation after incubation of platelets for 4 hours at 37 degrees C in the presence of lyoprotectant-trehalose, to protract the figures of loading efficiency and intracellular trehalose concentration versus incubation time, temperature and external trehalose concentration, to optimize loading parameters. The response of platelets to different agonists--thrombin, ADP, collagen and ristocetin were measured respectively by APACT2 aggregometer before and after loading trehalose into platelets; the expressions of CD62p and PAC-1 on platelet membranes in the presence and absence of reversible platelets activation inhibitors were measured by flow cytometry respectively before and after loading trehalose into cytoplasm of platelets. The results showed that the loading efficiency was linear to incubation time (2 hours later) and incubation temperature (rang from 30 degrees C to 40 degrees C), respectively. The loading efficiency almost reached 60% when the platelets were incubated at 37 degrees C for 4 hours. The intracellular trehalose concentration was higher with the increase of the extracellular trehalose concentration (< 50 mmol/L). Compared to untreated groups, the values of MPV and aggregation to different agonists in treated groups showed no significant difference, respectively (P > 0.01). After incubation of platelets for 4 hours, the expression of CD62p increased to some extent, however, the expression of CD62p decreased again when the reversible platelets activation inhibitor PGE-1 and adenosine were added to the incubation buffer. It is concluded that 37 degrees C, 4 hours and the extracellular trehalose concentration < 50 mmol/L are the optimal conditions for loading with trehalose. The processing of loading with trehalose before platelet lyophilization has no significant effects on response of platelets to agonists and activation.

Slide platelet aggregation test used as a monitor for patient treated with anti-pletelet drugs / 中国实验血液学杂志

The aim was to verify the effectiveness of slide platelet aggregation test (SPAT) to monitor the inhibition effect of anti-platelet drugs. A group of eight healthy volunteers was examined for SPAT value and T(50) (time necessary for reaching 50% of total aggregation) induced by ADP, arachidonic acid (AA) and cationic propyl gallate (c-PG) respectively before and after administration of ASA in dose of 100 mg/day for 3 days. The group of 41 inpatients at the Department of Cardiovascular Disease treated with anti-platelet drugs and the group of 327 healthy blood donors were also examined for SPAT. The SPAT value of healthy volunteer samples stored at room temperature were measured hourly for four hours. The results showed that: (1) no significant difference was detected between the T(50) before and after ASA administration in health volunteer group when ADP was used as inducer, but a significant difference was detected in this group when AA or c-PG was used as inducer. There was significant linear correlation between SPAT value and T(50) induced by c-PG in health volunteer group before and after administration of ASA (r = 0.998, P = 0.000); (2) there was no significant difference between the SPAT value of health volunteer group before administration of ASA and the SPAT value of health blood donors group (P = 0.853), but there was a significant difference between the SPAT values before and after administration of ASA in health volunteer group (P = 0.000). There was significant difference when the SPAT value of the inpatients treated with anti-platelet drugs was compared with that of healthy blood donor group and with that of health volunteer group before and after administration of ASA (P = 0.000). The cut-off value of SPAT in health blood donor group was 44.6 +/- 11.7 seconds, reference value was from 21.1 seconds to 68.0 seconds; (3) there was no significant difference between SPAT values when platelets samples stored at room temperature for 1, 2, 3, 4 hours (P = 0.815). In conclusion, SPAT can rapidly monitor the inhibition effect of anti-platelet drugs and SPAT may have the similar clinic value with T(50) induced by c-PG.

Collection of peripheral blood stem cells from ABO incompatible allogeneic donors by using blood cell separator / 中国实验血液学杂志

To evaluate the yield of the blood cell separator for collection of peripheral blood stem cells (PBSC) from ABO major and (or) minor incompatible allogeneic donors and the feasibility of PBSC component infusion to the recipients without removal of erythrocytes or plasma, the Cobe Spectra (Version 6.1) blood cell separator was utilized to collect PBSC component from 9 allogeneic donors. Of all the donors, 4 were ABO major incompatible, 2 were minor incompatible and the other 3 were both major and minor incompatible to corresponding recipients. In each cycle, different amount of PBSC component was harvested, and the variable volume plasma chased the cells into the bag was adjusted according to the ABO incompatibility. The nucleated cell count, percentage of mononuclear cell, number of CD34(+) cell and percentage of viable cell (trypan blue excluding rate) in the component were detected. At the time of infusion, a series of protective measures to the renal function of recipients were taken. The results showed that apheresis was twice performed on these eight donors to collected enough PBSC for transplantation or cryopreservation, except one apheresis was enough for cell amount needed by transplantation, as the donor's body weight was much heavier than that of the recipient. Altogether 17 apheresises were performed, the mean yield of nucleated cells was 3.77 x 10(10), in which 97% to 99% were mononuclear cells (MNC). The harvested number of CD34(+) cell was 8.62 x 10(6)/kg. All the trypan blue exclusion rate was 100%. In ABO major incompatible or both major and minor incompatible component, there were 8 - 10 ml packed erythrocytes; in ABO minor incompatible component, there were 80 - 120 ml of plasma. These components were infused into the recipients without removal of erythrocytes or plasma and no haemolytic reaction was observed in any recipient, and their hematopoietic functions soon recovered. Results suggest that enough PBSC can be acquired by using blood cell separator Cobe Spectra (Version 6.1), with the modified separation factors, and the collected PBSC component can be safely infused into the ABO incompatible recipients without removal of erythrocytes or plasma.

Optimization on trehalose loading technique as protective conditioning for lyophilization of human platelets / 中国实验血液学杂志

This study was aimed to further optimize trehalose loading technique including loading temperature, loading time, loading solution and loading concentration of trehalose, based on the established parameters. Loading efficiency in plasma was compared with that in buffer at 37 degrees C; the curves of intracellular trehalose concentration versus loading time at 37 degrees C and 16 degrees C were measured; curves of mean platelet volume (MPV) versus loading time and loading concentration were investigated and compared. According to results obtained, the loaing time, loading temperature, loading solution and trehalose concentration were ascertained for high loading efficiency of trehalose into human platelet. The results showed that the loading efficiency in plasma was markedly higher than that in buffer at 37 degrees C, the loading efficiency in plasma at 37 degrees C was significantly higher than that at 16 degrees C and reached 19.51% after loading for 4 hours, but 6.16% at 16 degrees C. MPV at 16 degrees C was increased by 43.2% than that at 37 degrees C, but had no distinct changes with loading time and loading concentration. In loading at 37 degrees C, MPV increased with loading time and loading concentration positively. Loading time and loading concentration displayed synergetic effect on MPV. MPV increased with loading time and concentration while trehalose loading concentration was above 50 mmol/L. It is concluded that the optimization parameters of trehalose loading technique are 37 degrees C (temperature), 4 hours (leading time), plasma (loading solution), 50 mmol/L (feasible trehalose concentration). The trehalose concentration can be adjusted to meet the requirement of lyophilization.

Inhibiting effect of adenosine on platelet activation in vitro / 中国实验血液学杂志

This study was aimed to investigate the inhibiting effects of adenosine on platelet in vitro in order to select functional protectants for platelets before lyophilization. Platelet membrane surface CD62P expression was assayed by flow cytometer (FCM). Platelet aggregations induced by restocetin, thrombin, ADP and propyl gallate were detected by APACT-2. The results showed that platelets membrane surface CD62P expression increased significantly after pre-treating of freeze-drying. 0.75 mmol/L adenosine could inhibit CD62P expression in a dose-dependent manner. Adenosine could inhibit platelet aggregation induced by propyl gallate, but no action on restocetin. When adenosine concentration was 1.0 mmol/L or higher, the aggregation induced by thrombin was significantly restrained. When concentration of adenosine was 0.75 mmol/L, platelet activation resulted from retreating could be inhibited and platelet aggregation induced by restocetin and thrombin were not affected markedly. It is concluded that adenosine can be one of the functional protectants and activation inhibitors in vitro for platelet cryo-preservation.

Application of cationic propyl gallate as inducer of thrombocyte aggregation for evaluating the platelet function of platelet donors / 中国实验血液学杂志

The purpose of study was to investigate the feasibility of the application of cationic propyl gallate (C-PG) as inducer of platelet aggregation for evaluating the platelet function of single-donor plateletpheresis and identifying the incidence of defective platelet function among donors. Experiments were as follows: 3 healthy volunteers' platelet aggregation induced by 100-300 micromol/L C-PG was determined by LG-PABER analyzer to observe the effect of C-PG concentration on platelet aggregation; 30 healthy volunteers' platelet aggregation before and 24 hours after administration of 200-400 mg acetylsalicylic acid (ASA) was examined after induction by 200 micromol/L C-PG for determining the cut-off value to discriminate platelet dysfunction donors; the platelet aggregation of 483 platelet donors was detected and the activated plasma clotting time (APCT) of donors who have deficiency in platelet aggregation was examined for investigating the incidence of defective platelet function among donors. The results showed that platelets were activated by C-PG induction in a dose dependent manner, when concentration of C-PG reached 200 micromol/L, the percentage of platelet aggregation was highest. It significantly decreased after 24 hours with ASA than that before the administration (P < 0.001), especially in 180 seconds induced by C-PG. If cut-off point was fixed on the platelet aggregation < 20% in 180 seconds, donors of platelet dysfunction can be selected effectively. 25 of defective platelet aggregation function among 483 donors were detected, and 11 out of 25 platelet dysfunction donors had the deficiency in procoagulant activity with prolonged APCT. It is concluded that C-PG as inducer of platelet aggregation is feasible to screen the platelet function of donors. Five percent of platelet donors has function defect examined by C-PG as inducer of platelet aggregation.

Measuring the shelf life of CPDA and ACD whole blood stored at above 4 degrees C in vitro / 中国实验血液学杂志

In order to measure the shelf life of whole blood stored at above 4 degrees C and provide experimental data for blood preservation and transportation in battle fields, 200 ml whole blood was collected from each of the 10 donors and anticoagulated by CPDA or ACD, then 50 ml whole blood was separated from each one and marked as control group, the rest was marked as test group. The control group was stored at 4 degrees C and RBC ATP concentrations was measured at the end of its shelf life which signed as critical ATP. The test group was stored at above 4 degrees C condition, some items as ATP, FHb (free hemoglobin), serum K(+) and germiculture were tested daily and ensured all of them eligible. When RBC ATP decreased to the level of critical ATP, the time of preservation was considered as shelf life. The results showed that at temperatures from 10 to 33 degrees C, the shelf life of CPDA whole blood ranges from 2.5 days to 18 days, while shelf life of ACD whole blood ranges from 1 day to 13 days. It is concluded that CPDA whole blood stored at above 4 degrees C condition can be sent to the front hospital in effective shelf life so that the wounded can be cured in time.

Determination and comparison of anti-SARS antibody in children and adults / 中国实验血液学杂志

To investigate the positive rate of anti-SARS antibody in children and adults without SARS, 197 paediatric patients under 14 years old from inpatient and outpatient department of our hospital, 156 healthy children pupils from primary school, 453 adult patients over 18 years old from inpatient and outpatient department of our hospital and other 502 healthy adult blood donors were selected. Anti-SARS antibodies were determined by anti-SARS specific antibody detection kit and ELISA method. The results showed that both the positive rates of IgG antibody in paediatric patients and healthy children were about 2% (4/197 and 3/156), while the positive rates in adult patients and healthy adults were about 0.2% (1/453 and 1/502). The difference between the positive rates of children and adults was significant (chi(2) = 11.61, P < 0.001). IgM antibody was negative in all the samples. It is concluded that the anti-SARS IgG antibody positive rate in children was obvious higher than that in adults. This may be the cause why the cases with SARS in children is much less than in adults.

Effects of preparation and quality control of cryopreserved platelets / 中国实验血液学杂志

The purpose of this study was to establish a set of techniques for cryopreservation of platelets with dimethylsulphoxide (DMSO) to insure high quality of cryopreserved platelet. The methods were as following: (1) DMSO was filtered in stead of being sterilized before infusion into the bag with platelets. (2) The whole blood was centrifuged immediately after blood collection and the attached tube was tied on the top of the bucket. (3) The related centrifugal force was 480 x g, the accelerating and braking grades of the centrifuge for acceleration and deceleration were 9 and 4 respectively. (4) The flow rate of platelet rich plasma (PRP) could not be too high, 80 - 100 ml PRP should be harvested at 1 minute or so. The infusion rate of DMSO into the PRP was 1 ml/min. After the infusion of DMSO, the PRP bag must be put into the -80 degrees C ultra low freezer at once to make the product to be freezed as soon as possible. The cryopreserved platelet should be thawed in the cycling warm water at the temperature of 38 - 40 degrees C. (5) After thawing of platelet, the platelet, red blood cell and white blood cell were counted, and the bacteria culturing, tests for HBsAg, anti-HCV, anti-HIV, TP and ALT were carried out. The results showed that altogether 14 800 units of cryopreserved platelets were prepared including 80 units collected with blood cell separator, of which quality control was accomplished in 300 units. The manually collected platelet mean count >/= 2.4 x 10(10)/unit, while the apheresis platelet count >/= 2.5 x 10(11)/unit. The yield was over 70%. The contaminated red and white blood cells were </= 1 x 10(9) and </= 1 x 10(7)/unit respectively. All the bacteria cultures were negative, while tests for HBsAg, anti-HCV, anti-HIV and TP were negative too. The ALT values were all in normal range. The transfusion of cryopreserved platelets showed obvious effect of haemostasis. In conclusion, the cryopreserved platelets prepared with this method were of high quality and efficaciousness in haemostasis clinically.

Comparison of platelet activators used in slide platelet aggregation test / 中国实验血液学杂志

The study was purposed to explore the suitable platelet activators to be used in slide platelet aggregation test. Experiments were as follows: (1) to detect the intensity and time in 15 healthy donors' platelet aggregation tests induced by cationic propyl gallate (c-PG) and the usual platelet activators: ADP, collagen, epinephrine, arachidonic acid and ristocentin, respectively; (2) to detect the time in platelet aggregation tests of 15 healthy donors induced by c-PG and the above usual platelet activators respectively after addition of PGI2, cAMP or EDTA; (3) to detect the time in 15 healthy donors' platelet aggregation tests induced by c-PG after addition of heparin; (4) to detect the intensity and time of platelet aggregation induced by c-PG at the platelet count of (240-15) x 10(9)/L, (5) to detect the time of platelet aggregation induced by c-PG in eight patients each of whom had taken 100 mg aspirin per day for five days. The results showed that (1) c-PG reduced the strongest intensity of platelet aggregation and the time taken was appropriate, (2) c-PG was the most effective activator to reveal the inhibitive effect on platelet by PGI2, cAMP or EDTA, (3) 0.5 - 3 U/ml heparin did not significantly change the platelet aggregation induced by c-PG, (4) 15 healthy donors' platelet aggregation induced by c-PG displayed clearly on the slide until the platelet count below 30 x 10(9)/L, (5) The platelet aggregation time induced by c-PG was significantly prolonged in eight patients who had taken aspirin. In conclusion, compared to the usual platelet activators, c-PG has remarkable potential advantages when used in slide platelet aggregation test.

Establishment and evaluation on the method for platelet intracellular trehalose determination / 中国实验血液学杂志

This study was aimed to establish an applicable, convenient and rapid method for platelet intracellular trehalose determination, so that the technique of trehalose loading could be optimized and used in research on freeze-drying platelets. Protein from loaded-trehalose platelets was deposited by using trichloroacetic acid, trechalose concentration in platelets was determinated by sulfuric-anthrone reaction and was analyzed by high performance liquid chromatography (HPLC). The results showed that when platelets were loaded with 1.7% of trehalose in loading solution, intracellular concentration determinated by sulfuric-anthrone reaction was 0.22% and derterminated by HPLC was 0.2%. The recovery rate of trehalose determinated by sulfuric-anthrone reaction was 100.7% and stability and repeatability of results were good. In conclusion, the method is convenient, rapid, accurate and highly sensitive for determination of platelet intracellar trehalose.