[The effect of platelet infusion on the repair of bone marrow hematopoietic niche damage in mice induced by (60)Co radiation and hematopoietic reconstruction after bone marrow transplantation].

Objective: To observe the effect of platelets on hematopoietic stem cell (HSCs) implantation in mice with radiation-induced bone marrow injury and bone marrow transplantation models. Methods: ①Male C57BL/6 mice were divided into a single irradiation group and a radiation infusion group after receiving (60)Co semimyeloablative irradiation for 18-10 weeks. The irradiation infusion group received 1×10(8) platelets expressing GFP fluorescent protein. ② The allogeneic bone marrow transplantation model was established. The experimental groups included the simple transplantation group (BMT) and the transplantation infusion group (BMT+PLT). The BMT group was infused through the tail vein only 5 × 10(6) bone marrow cells, the BMT+PLT group needs to be infused with bone marrow cells at the same time 1× 10(8) platelets. ③ Test indicators included peripheral blood cell and bone marrow cell counts, flow cytometry to detect the proportion of hematopoietic stem cell (HSC) and hematopoietic progenitor cells, bone marrow cell proliferation and apoptosis, and pathological observation of vascular niche damage and repair. Results: ①On the 3rd, 7th, 14(th), and 21st days after irradiation, the bone marrow cell count of the infusion group was higher than that in the single irradiation group (P<0.05), and the peripheral blood cell count was also higher. A statistically significant difference was found between the white blood cell count on the 21st day and the platelet count on the 7th day (P<0.05). In the observation cycle, the percentage of bone marrow cell proliferation in the infusion group was higher, while the percentage of apoptosis was lower. ② The results of bone tissue immunofluorescence after irradiation showed that the continuity of hematopoietic niche with red fluorescence was better in the irradiation infusion group. ③The chimerism percentage in the BMT+PLT group was always higher than that in the BMT group after transplantation.④ The BMT+PLT group had higher bone marrow cell count and percentage of bone marrow cell proliferation on the 7th and 28th day after transplantation than that in the BMT group, and the percentage of bone marrow cell apoptosis on the 14th day was lower than that in the BMT group (P<0.05). After the 14th day, the percentage of stem progenitor cells in the bone marrow cells of mice was higher than that in the BMT group (P<0.05). ⑤The immunohistochemical results of bone marrow tissue showed that the continuity of vascular endothelium in the BMT+PLT group was better than that in the BMT group. Conclusion: Platelet transfusion can alleviate the injury of vascular niche, promotes HSC homing, and is beneficial to hematopoietic reconstruction.

[The function of NLRP1 in noninfectious pulmonary injury following allogeneic hematopoietic stem cell transplantation].

Objective: To explore the function of NLRP1 in noninfectious pulmonary injury (nonIPI) after allogeneic stem cell transplantation (allo-HSCT) . Methods: In this study, we established the model of allo-HSCT with C57BL/6 and NLRP(-/-) mouse as recipients. Chimera rate was measured by flow cytometry. The HE staining was used to observe the pathology changes in the lungs. NLRP1 and relevant inflammatory proteins were measured by Western Blot. Results: On the day 14 after allo-HSCT, the chimera rate was more than 96%, HSCs of donors had been successfully transplanted into recipients. HE staining showed that nonIPI occurred after allo-HSCT. The degrees of injuries reached the peak on day 21. In addition, the expressions of MPO, NLRP1, p20, Mature-IL-1ß and Mature-IL-18 had same tends with the degrees of nonIPI. When we knocked out NLRP1 gene of recipients, the degrees of nonIPI reduced and the expressions of MPO, p20, Mature-IL-1ß and Mature-IL-18 were less than in non-knockout group. Conclusion: allo-HSCT could cause nonIPI and high expressions of MPO, p20, IL-1ß, IL-18, NLRP1. Knocking out NLRP1 gene could alleviate the degrees of nonIPI and reduce the expressions of relevant inflammatory proteins, indicating that NLRP1 might be one of factors contributed to nonIPI after allo-HSCT.

[Effects of allogeneic hematopoietic stem cell transplantation in combination with infusion of endothelial progenitor cells on bone marrow inflammatory injury].

Objective: To explore effects of allogeneic hematopoietic stem cell transplantation (HSCT) in combination with infusion of endothelial progenitor cells (EPC) on bone marrow inflammatory injury. Methods: 6-8 weeks BALB/c (H-2K(d)) mice after lethal dose of irradiation (TBI) were subjected to allogeneic bone marrow transplantation (BMT group) or co-transplantation of EPC (EPC group) . Samples of bone marrow cells of mice in each group on days 7,14,21,28 after transplantation were obtained to detect EPC cultural and cell chimeric rates by flow cytometer. Mice were sacrificed on days 7, 14, 21 and 28 post HSCT to analyze bone marrow pathology by H&E staining, the infiltration of macrophages and neutrophils by Western blot, validation expression levels of inflammatory complexes nlrp1、nlrp6 and its downstream molecules casepase-1 by Q-PCR and Western blot. Results: Cell chimeric rate on day 7 after transplantation in EPC group[ (91.65±2.77) %] was significantly higher than in BMT group[ (83.69±1.26) %]. Alleviated osteomyelitis injury and inflammatory cell infiltration in EPC group were observed when compared with BMT mice. Also significant reductions of the levels of nlrp1、nlrp6、casepase-1 transcription complexes in EPC mice were noted when compared with BMT ones. Conclusion: Co-transplantation of HSC and EPC could alleviate inflammatory cell infiltration and activation of the complex to promote the repair of bone marrow.

Development of a new animal model of liver cirrhosis in swine.

This study aimed to develop a new experimental model of liver cirrhosis in swine by using carbon tetrachloride (CCl(4)) and ethanol. Liver cirrhosis was induced by intraperitoneal injection of CCl(4) twice a week for 9 weeks. Maize flour was the only food provided and the animals drunk a 5% alcohol-water mixture. Alanine aminotransferase (ALT), aspartate aminotransferase (AST), albumin, bilirubin and portal venous pressure (PVP) levels were determined throughout CCl(4) treatment. The animals were sacrificed under general anesthesia at week 9 and liver samples were collected for histological analysis. 83.3% of the swine had liver cirrhosis and 33.3% had died. There was no change of body weight during the course of the experiment (p > 0.05). The AST and ALT levels increased significantly in the early stage of the study but had a trend to decrease during the late phase. The level of bilirubin increased greatly and albumin decreased during the whole experiment (p < 0.05). PVP levels decreased in the early stage in CCl(4)-treated swine, but increased significantly at the late phase. In conclusion, this study was successful in producing liver cirrhosis and offers an ideal experimental model for observing surgical therapeutic efficacy.

Spectroscopic study on the photoinduced reaction of fullerene C60 with aliphatic amines and its dynamics--strong short wavelength fluorescence from the adducts.

The photoinduced electron donor acceptor interactions of C60 with eight kinds of aliphatic amines, namely dicthylamine (DEA), triethylamine (TEA), tri-n-amylamine (TAA), propylethylamine (PPA), n-butylamine (BTA), n-heptylamine (HPA) and dodecylamine (DDA) and ethylenediamine (EDA) are reported by a comprehensive spectroscopic study. Experiments show that there is a good discipline with different structure and the length of n-alkyl group both in their ground and excited states. At the same time, a slow reaction takes place between C60 and various amines with a gradual increase in the concentration of various aliphatic amines or the standing of solution, which can be dramatically catalyzed by UV-radiation. The final products can all emit a strong fluorescence at the relatively shorter wavelength around 519 nm. On this basis, the dynamic properties of C60/aphaliticamines including the enthalpy of activation (deltaH++et) and entropy activation (deltaS++et), together with all sorts of influence factors are firstly investigated in this work. The possible reaction mechanisms are explored, also.

Recognition and simultaneous determination of ofloxacin enantiomers by synchronization-1st derivative fluorescence spectroscopy.

Under controlling pH 3, R-(+)- and S-(-)-ofloxacin (OFLX) enantiomers can be well recognized and resolved by the synchronization-1st derivative fluorescence spectroscopic techniques, and the interference from urine blank also can be eliminated. The linear dynamic ranges are 0.36-2.16 (R), 0.36-2.89 and 3.16-31.6 mug/ml (S), respectively, for determining OFLX in urine samples. The limits of detection are 0.36 mug/ml (R) and the recoveries of R-(+)- and S-(-)-OFLX in urine samples are 97-104%. Relative standard deviation is <6.6%. Pharmacokinetic study of OFLX and levofloxacin shows that R-(+)- and S-(-)-ofloxacin reach their peak concentration in urine samples after a healthy subject has taken tablets for approximately 3 and 6 h, respectively. R-(+)-OFLX can be obviously detected in 5-6 h after a healthy subject has taken tablets, indicating the transformation of S-(-)- to R-(+)-OFLX enantiomer in human body (in vitro).