BACKGROUND: Whole blood viscosity is the keystone in hemorheological research, which has important significance in the exposure of the generation of ischemic diseases including myocardial infarction (MI) and cerebral infarction(CI) due to hemorheological changes.OBJECTIVE: To investigate the characters of macroscopical and microscopical hemorheology to explore the standardization of hemorheological measuring method.DESIGN: An observatory comparative study based on the venous blood of healthy individual.SETTING: Department of physics in a medical college.MATERIALS: Venous bloods of 86 healthy individuals were randomly selected for the study, which was conducted in the Laboratory of Hemorheology of Guilin Medical College.METHODS: Totally 86 whole blood samples were tested under 7 shear rates (0.6 s-1,2 s-1,5 s-1, 10 s-1, 20 s-1, 40 s-1, 100 s-1) from low shear rate to high shear rate, and then from high shear rate to low shear rate. The measuring value of the two processes was compared.Casson viscosity and yield stress in two measuring process.RESULTS: There was no significant difference of apparent viscosity( P＞ 0.05 ) except the 0.6 s- 1 -corresponding apparent viscosity ( P ＜ 0.05 )at some shear rate in two measuring process. There was no significant difference in Casson viscosity and yield stress( P ＞ 0.5, P ＞ 0. 3).CONCLUSION: The measurement of Casson viscosity and yield stress is good for the optimization of the standardization of hemorheological indicators and measuring method; and it is feasible to test apparent viscosity, Casson viscosity and yield stress repeatedly in same blood sample, which has important significance in the exposure of the hemorheological changes and the generation and development mechanism of ischemic diseases including MI,CI, hypertension, and coronary heart disease(CHD).

AIM:To explore the effect of HbA1c level in the patients with type 2 diabetes mellitus (T2DM) on the rheological properties of erythrocytes and the structure of hemoglobin (Hb).METHODS:The patients with T2DM were classified into 3 groups:the patients with good glycaemic control (group A, HbA1c<7.0%), the patients with poor glycaemic control (group B, 7.0%≤HbA1c<9.0%) and the patients with persistent hyperglycemia (group C, HbA1c≥9.0%) .The rheological properties of a single living erythrocyte were analyzed by the techniques of static imaging and anal -ysis.Ultraviolet-visible spectroscopy was used to study the structure of Hb .RESULTS: Compared with group H , the roundness effect factor (REF) of erythrocytes, which was positively related with HbA1c level, was significantly increased in groups A, B and C (P<0.05).The contact area of erythrocytes in group B and all the morphological parameters of erythrocytes in group C were significantly higher than those in group H ( P <0.05 ) .There were significant differences among groups A , B and C in deformation capacity and elastic parameters of the cell membrane ( P<0.05 ) , but with no difference in the long axis and short axis between group A and group B .Compared with group H , no obvious change in the spectral pattern and spectrum peak of Hb in groups A , B and C was observed.However, the absorbance of Hb, which showed a trend of gradual decline with the increase in HbA 1c level, in group B and group C was significantly decreased as compared with group H (P<0.01), and the Hb absorbance in group C were also lower than that in group A (P<0.05). CONCLUSION:With the increase in HbA1c level, the morphology along with the deformation function of erythrocytes in T2DM changes and declines gradually , and the structure of Hb may also change .