BACKGROUND:Hemostatic dressing can directly contact with the body tissues on the wound surface. The biocompatibility is one of the important indicators of evaluating the advantages and disadvantages of dressing. The hemostatic dressing prepared with calcium alginate as raw material has become a research focus owing to its low cost and good compatibility. OBJECTIVE:To observe the cytotoxicity of calcium alginate hemostatic dressings and to compare the cytotoxicity between calcium alginate hemostatic dressing and gelatin hemostatic sponge, absorbing cotton, ordinary gauze. METHEDS:Leaching solution method: the DMEM high glucose culture solution was taken as the leaching medium. The calcium alginate hemostatic dressing, gelatin hemostatic sponge, absorbing cotton and ordinary gauze leaching solution were respectively prepared. Five concentration gradients of 100%, 75%, 50%, 25%, 50% were set. The fibroblast cels of L-929 mouse were cultured for 24 hours with the above material leaching solution. The volume fraction of 10% DMEM high glucose culture medium was taken as control group, and DMEM high glucose culture medium containing 5% DMSO was taken as positive control group to observe the cel proliferation and morphological changes. Direct contact method: The fibroblast cels of L-929 mouse were respectively seeded in calcium alginate hemostatic dressing, gelatin hemostatic sponge, absorbing cotton and ordinary gauze and cultured for 24 hours. The changes in cel morphology were observed.
RESULTS AND CONCLUSION: Leaching solution method: The cytotoxicity of alginate fiber hemostatic dressing, gauze, absorbing cotton leaching solution with different concentration gradients was grade 1, which was in line with GB/T16886/ ISO10993 biological evaluation standard of medical apparatus and instruments. The cytotoxicity of 100%, 75% gelatin hemostatic sponge extract solution was grade 3, causing severe inhibition of cel proliferation. Direct contact method: The cytotoxicity of gauze and alginate fiber hemostatic dressing was grade 1, absorbing cotton was grade 2, gelatin hemostatic sponge was grade 3. These results demonstrate that calcium alginate hemostatic dressing has no cytotoxicity.

BACKGROUND:In recent years, calcium alginate dressing has been widely used in surgical hemostasis, traumatic hemostasis, postoperative nasal hemostasis and puncture site hemostasis,etc.; however, there are few reports on their hemostatic mechanisms. OBJECTIVE: To preliminarily study the hemostatic mechanism of calcium alginate dressing. METHODS: Human anticoagulant blood was respectively dropped on sodium alginate dressing, nasopore dressing and medical cotton gauze. After 2 minutes, the interaction between materials and blood was observed at the room temperature using scanning electron microscopy. Calcium alginate dressing, nasopore dressing and medical cotton gauze were added in human red blood cel suspensions respectively. After 15 minutes, the interaction between materials and red blood cels was observed using scanning electron microscopy. The red blood cels were suspended by different concentrations (10, 5, 2.5 g/L) of alginate dressing extracts. The erythrocyte sedimentation rate was observed at different time points (30, 60, 120 minutes). Platelets rich plasma was incubated with different concentrations (10, 5, 2.5 g/L) of alginate dressing extract at 37℃, then CD62P positive platelet percentage was measured by flow cytometry after 10 minutes of incubation. RESULTS AND CONCLUSION: Dense fibrin network was formed after calcium alginate dressing contacting with an anticoagulant. A large number of blood cels were recruited. There were only a smal amount of red blood cels and platelets adhesion in the nasopore dressing and medical cotton gauze groups. After the calcium alginate dressing interacting with red blood cels, red blood cel deformability was visible, with a pseudopodia-like change. The red blood cel morphology was unchanged in the nasopore dressing and medical cotton gauze groups. The calcium alginate dressing extract dose-dependently and time-dependently increased the red blood cels aggregation, comparative differences between groups was statisticaly significant(P < 0.01). The calcium alginate dressing extract dose-dependently enhanced the CD62P positive platelet percentage, comparative differences between groups was statisticaly significant (P< 0.01). These results demonstrate that calcium alginate dressing promotes hemostasis and coagulation process by releasing of calcium ions, causing red blood cel aggregation and deformation and activating platelets.

The elbow is more susceptible to motion loss than other joints after trauma,and elbow stiffness leads to functional impairment in the upper limb and interferes with daily activities.Open arthrolysis is the most common and classical treatment for post-traumatic elbow stiffness.In this paper,we review the treatment protocols like preoperative clinical evaluation,arthrolysis strategies and postoperative rehabilitation program for post-traumatic elbow stiffness,discuss relevant issues and assess their prospects.

【Objective】 To investigate the resource allocation status of blood testing laboratories in 14 blood stations in Gansu Province, explore the impact of differences in basic conditions on the comprehensive testing ability of laboratories, so as to promote the homogenization and standardization of blood screening capacity in blood stations in Gansu and improve blood safety and effectivenes. 【Methods】 An evaluation index system of laboratory resource allocation was constructed and a question-naire was designed. The data of human resources, infrastructure and key equipment of 14 blood stations were collected. The entropy weight -TOPSIS method was used to evaluate and rank the resource allocation of 14 blood stations. 【Results】 In the comprehensive evaluation of blood testing laboratory resource allocation in 14 blood stations in Gansu, the top three were laboratories A, B and I, and the last three were laboratories G, M and J. On the whole, the main issue was unreasonable structure of human resources: most laboratories had unreasonable age structure; except for Laboratory A, there was no personnel with bachelor's degree or above in laboratories; most laboratories had not established a team with intermediate professional titles. In terms of infrastructure, the size of seven laboratories could not meet the needs of modern laboratory testing, and all eight blood stations had no spare nucleic acid laboratories nor a mutual spare laboratory with other blood stations As for the key equipment, 5 laboratories had no automatic blood grouping diagnostic instrument, 5 laboratories only had one set of enzyme immunoassay detection system, 3 laboratories had no spare equipment for the key equipment, which means if the equipment failure could not be repaired in time, the release of results would be affected. 【Conclusion】 There were significant differences in human resources, infrastructure and key equipment of blood testing laboratories in 14 blood stations in Gansu, which had a great impact on laboratory testing capacity and subsequent development. It is suggested that governments at all levels and health administrative departments optimize the input of laboratory resource allocation according to the blood collection volume of blood stations to gradually narrow the differences in resource distribution between different regions, improve the degree of laboratory automation and optimize the personnel structure, so as to build high-quality and efficient blood testing laboratories and ensure the safety of clinical blood use.

ObjectiveTo observe the therapeutic effect of BD-77 by nebulized inhalation on animal models of various respiratory viral infections and investigate the mechanism of broad-spectrum antiviral action of BD-77 using proteomics. MethodThe influenza virus H1N1/FM1 experiment used ICR mice and divided them into a normal group， model group， Tamiflu group， and BD-77 groups of 75 and 37.5 g·L^-1 for inhalation of 20 min and 25 min. Human coronavirus 229E and OC43 experiment divided the BALB/c mice into a normal group， model group， chloroquine phosphate group， and BD-77 groups of 75， 37.5， 18.75， and 9.375 g·L^-1， with 10 mice in each group. Influenza virus H1N1/FM1 and human coronaviruses 229E and OC43 infection-induced pneumonia models were used to detect mouse lung index， and real-time fluorescence quantitative polymerase chain reaction （Real-time PCR） was used to detect the viral load in lung tissue. Enzyme-linked immunosorbent assay （ELISA） was used to detect related inflammatory factors in lung tissue， and proteomics analysis was performed on the lung tissue of OC43-infected mice. ResultCompared with that in the normal group， the lung index of mice in each infection group was significantly increased （P<0.01）， and viral nucleic acid could be detected in the lung tissue of mice infected with human coronaviruses 229E and OC43. The levels of interleukin-6 （IL-6）， IL-10， and tumor necrosis factor-α （TNF-α） in the lung tissue of mice infected with human coronavirus 229E were all significantly increased （P<0.01）. BD-77 could significantly reduce the lung index of mice infected with influenza virus H1N1/FM1 and human coronaviruses 229E and OC43 （P<0.05， P<0.01）， cut down the viral load in the lungs of mice infected with human coronaviruses 229E and OC43 （P<0.01）， and lower the contents of IL-6， IL-10， and TNF-α in the lung tissue of mice infected with human coronavirus 229E （P<0.01）. Proteomics analysis of the lung tissue of OC43-infected mice showed that BD-77 regulated the AMPK signaling pathway， TNF signaling pathway， NOD-like signaling pathway， IL-17 signaling pathway， Forkhead box protein O （FoxO） signaling pathway， transforming growth factor-β （TGF-β） signaling pathway， and other signaling pathways. ConclusionNebulized inhalation of BD-77 is effective in treating pneumonia caused by influenza virus H1N1/FM1 and human coronaviruses 229E and OC43 infection in mice and may exert its antiviral effects by regulating the balance of cellular metabolism， enhancing the immune function of the host， and attenuating inflammatory responses.