BACKGROUND: A large number of studies mainly concern the proliferation effect of mesenchymal stem cells on hematopoietic stem cells in vitro and that bone marrow mesenchymal stem cell transplantation can reduce the death of hematopoietic cells caused by irradiation, increase the survival of bone marrow cells and repair hematopoiesis, while few of them investigate the repair of human umbilical cord blood mesenchymal stem cells transplantation on bone marrow hematopoiesis injury. OBJECTIVE: To explore the repair of hematopoietic microenvironment of bone marrow by human umbilical cord blood mesenchymal stem cells. METHODS: Male BALB/c mice were randomly divided into three groups. The mice in experimental group and control group were irradiated with total dose of 6-Gy X-ray to establish a mouse model of bone marrow hematopoietic injury. The normal group contained untreated normal mice. In the experimental group, CM-DiL labeled human umbilical cord blood mesenchymal stem cells were injected into the tail vein of each mouse at 5×106 (0.2 mL). The control group and the normal group received normal saline 0.2 mL through the tail vein. The peripheral blood hematology and bone marrow hematopoietic microenvironment repair were observed at 1, 5, 7, 14 and 21 days after cell transplantation. RESULTS AND CONCLUSION: Peripheral blood condition: At 1, 5 and 7 days after transplantation, the leucocyte, platelet, erythrocyte count and hemoglobin concentration in the experimental group and control group decreased progressively compared with the normal group. The most obvious decrease occurred on day 7. The trilineage recovered on day 14 after transplantation, basically returned to normal on day 21 after transplantation. Compared with the experimental group, the decrease of the trilineage in the control group was more obvious. The recovery was obvious faster in the experimental group than in the control group on day 14 after transplantation. Bone marrow smears: Bone marrow smears showed that the hematopoietic function was inhibited in the experimental group and the control group at 1, 5, 7, and 14 days after transplantation, especially on day 7. Bone marrow proliferation recovered on day 14 after transplantation. It was better in the experimental group than in the control group. On day 21 after transplantation, the hematopoietic function of bone marrow of mice in the experimental group and the control group recovered, and there was no difference between the experimental group and the control group compared with the normal group. Bone marrow pathological section: Bone marrow pathological sections showed that at 1, 5, 7, and 14 days after transplantation, the hematopoietic function of bone marrow in the experimental group and the control group was inhibited. On day 14 after transplantation, the bone marrow hematopoietic function of the experimental group and the control group began to recover, but the bone marrow proliferation of the experimental group was better than that of the control group. On day 21 after transplantation, there was no difference in the bone marrow proliferation between the experimental and the control groups and the normal group. The results suggested that human umbilical cord blood mesenchymal stem cells can promote the recovery of hematopoietic function of bone marrow.

Objective To investigate the association between non-Hodgkin lymphoma (NHL) and hepatitis B virus (HBV). Methods The serum HBV markers in 305 NHL patients who were diagnosed in the Affiliated Hospital of Southwest Medical University from January 2014 to December 2016 was detected by automatic chemiluminescence immunoassay. The infection rate of HBV in NHL patients was compared with that in 312 colorectal cancer patients and the national general population (81775 peoples). Results The positive rates of hepatitis B surface antigen (HBsAg), hepatitis B surface antibody (HBsAb) and hepatitis B core antibody (HBcAb) in 305 patients of NHL were compared with the general population [19.0 ％ (58/305) vs. 7.2 ％ (5888/81775), 44.3 ％ (135/305) vs. 50.1 ％ (40969/81775), 45.9 ％ (140/305) vs. 34.1 ％(27885/81775)], and the differences were statistically significant (χ2 values were 63.1, 4.1, 18.8, all P<0.05). The positive rate of HBsAg in NHL patients was compared with colorectal cancer patients and the general population, and the differences were statistically significant (χ2= 65.7, P< 0.01). The positive rate of HBsAg in B-cell NHL was statistically different from T-cell NHL [21.3％(51/239) vs. 10.6％(7/66),χ2=3.869, P<0.05]. But the positive rate of HBcAb and HBsAb in B-cell NHL were compared with T-cell NHL, and there was no statistically significant difference (both P> 0.05). Among 133 NHL patients, the HBV DNA positive rate was 33.1 ％ (44/133), and 74.1 ％ (43/58) in 58 cases of HBsAg-positive NHL, while 4.2 ％ (1/24) in 24 cases of HBsAg-negative but HBcAb-positive NHL. Conclusions The infection rate of HBV in NHL patients is higher than that in colorectal cancer patients and the general population, in which the occult HBV infection is worthy of much attention. The positive rate of HBsAg in T-cell NHL patients is lower than that in B-cell NHL patients. For NHL patients with HBV infection, anti-HBV treatment to prevent reactivation of the virus should be given before the anti-tumor treatment.