As a major component of the hematopoietic microenvironment,stromal cells have been proved to support hematopoiesis. This review describes the constitution, origin of stromal cells and its mrechanism of regulate hematopoiesis, and then elaborates that the stromal cells play a important role in the hematopoietic restitution of hematopoietic stem cell transplantation.

【Objective】 To investigate the feelings of blood donors during blood donation and its influencing factors, thus providing references for high quality blood donation service for blood banks. 【Methods】 A self-developed questionnaire concerning voluntary blood donation was randomly issued by the research group and recruited investigators among blood donors in 6 street blood donation sites of Nanjing Red Cross Blood Center at weekends during December 1~23, 2018. The basic information of blood donors, the difference of feelings during blood donation and the influencing factors were analyzed by descriptive analysis, chi-square test and binary Logistic regression analysis, respectively. 【Results】 A total of 405 questionnaires were issued, and all 405 copies were valid, with the response rate at 100% (405/405). Among the valid questionnaires, 46.67% (189/405) were first-time blood donors, 27.65% (112/405) had donated for 2~3 times, and 25.68% (104/405) donated more than 4 times. 53.59%(97/181), 23.7%(43/181) and 22.65%(41/181) of the above three groups of blood donors worried about the needles, and 55.48%(81/146), 22.60%(33/146) and 21.92%(32/146) worried about the blood outflow, 52.69% (88/167), 28.14% (47/167), and 19.16% (32/167 )worried about the pain during blood collection (P<0.05). The anxiety of unqualified blood test was similar to that of poor service (P>0.05). There were differences in blood donation experience among the three groups (P<0.05), and gender (P<0.05) was its influencing factor showed by binary Logistic regression analysis. 【Conclusion】 The majority of blood donors, who have donated at the street sites of Nanjing, are worried during blood donation collection. Therefore, the blood centers should provide high-quality services and humanized nursing interventions as well as strengthen the citizens′ awareness of blood donation.

Blood-brain barrier (BBB) precisely controls the material exchange between the blood and brain tissue, and plays a critical role in the maintenance of brain microenvironment homeostasis. Brain microvascular endothelial cells connect tightly with each other and intertwine with surrounding pericytes and astrocytes to form the BBB. These cells regulate the development and function of the BBB through expressing tight and adherens junction proteins, transporters, and relevant signal molecules. Neurons and microglia can also regulate the function of BBB in physiological and pathological conditions. Recent studies indicate that the occurrence and progress of various neurological diseases are accompanied with structural and functional impairment of the BBB. Therefore, elucidation of the mechanisms underlying BBB development and function will further benefit our understanding of neurovascular interaction and provide an important theoretical basis for the treatment of neurological diseases. In this review, we briefly summarize the progress of BBB research.
Astrocytes ; Blood-Brain Barrier ; Brain ; Endothelial Cells ; Homeostasis ; Microglia ; Neurons ; Pericytes