Objective To investigate the impact of low intensity pulsed ultrasound (LIPUS) with different intensities on the migration of bone marrow mesenchymal stem cells (BMSCs) in vitro.Methods BMSCs were divided into control group,30 mW/cm2 group,60 mW/cm2 group and 90 mW/cm2 group.Control group was treated by sham LIPUS exposure,and the other three groups were treated by LIPUS with corresponding intensities.The impact of LIPUS on scratch healing was tested with scratch assay,and the interference of proliferation was eliminated with MTT assay.The migration of BMSCs were evaluated with transwell migration assay.The expression of F-actin was analyzed with fluorescein isothiocyanate (FITC) fluorescent coloration.Results 24 h and 48 h after LIPUS exposure,there were statistical differences of scratch area among groups (F=26.559,106.110,both P＜0.001),and the scratch area of control group was the largest ([0.93 ± 0.26)mm2 of 24 h after LIPUS exposure and [0.70 ± 0.11]mm2 of 48 h after LIPUS exposure),while that of 30 mW/cm2 group was the smallest ([0.47 ±0.21]mm2 of 24 h after LIPUS exposure and [0.19±0.10]mm2 of 48 h after LIPUS exposure).There was no statistical difference of scratch area among the four groups immediately after LIPUS exposure (F=2.921,P=0.063).MTT assay results showed there was no statistical difference of absorbance among the four groups immediately,nor 24 h,48 h after LIPUS exposure (F=1.616,0.720,1.408;P=0.196,0.544,0.378).Significant difference was found in the number of cells migrated through the transwell chamber among the four groups (F=43.145,P＜0.001),and the cell number of 30 mW/cm2 group was the largest (212.53±35.32),while that of the control group was the least (89.53±19.27).F-actin fluorescence staining results showed the morphology of F-actin was changed after LIPUS exposure.The cytoskeleton became narrow and elongated.Statistical difference of relative fluorescence intensity was found among the four groups (F 64.350,P＜0.001).The relative fluorescence intensity of 30 mW/cm2 group was the largest (125.43 ± 17.43),while that of control group was the least (51.94± 12.76).Conclusion LIPUS can promote the migration ability of BMSCs in vitro with the best intensity was 30 mW/cm2.

Polyhydroxyalkanoates (PHA) synthesis by activated sludge using volatile fatty acids (VFAs) in fermentation liquid of excess sludge as carbon source is a hotspot in the field of environmental biotechnology. However, there is no unified conclusion on the effects of non-VFAs, mainly dissolved organic matter (DOM), on PHA production. Thus, this critical review mainly introduces the main characteristics and common analysis methods of DOM in anaerobic fermentation liquid. The effects of DOM on PHA production are analyzed from the aspects of microbiology, metabolic regulation and sludge properties. The results of different studies showed that high concentration of DOM is bad for PHA production, but an appropriate amount of DOM is conducive to the stability of sludge properties, reducing the final PHA purification cost. Finally, suitable strategies were proposed to regulate the PHA synthesis by activated sludge with DOM for PHA production by anaerobic fermentation liquid.
Anaerobiosis ; Bioreactors ; Fatty Acids, Volatile ; Fermentation ; Polyhydroxyalkanoates ; Sewage

OBJECTIVE: To investigate the effect of low-intensity pulsed ultrasound (LIPUS) on hematopoietic function in rats after combined chemotherapy with doxorubicin and cyclophosphamide. METHODS: Eighty rats were randomized into control group and LIPUS group (=40) for treatment with intraperitoneal injection of doxorubicin (2 mg/kg)+cyclophosphamide (20 mg/kg) for 4 consecutive days and continuous irradiation with LIPUS for 7 days following the injections, respectively. The white blood cells, red blood cells and platelets counts in each group were measured at 0, 4, 7, 9, 11, 14 and 18 days after the start of drug administration. The pathological sections of the bone marrow were examined at 0, 4 and 11 days, and the flow cytometry was performed for detecting the cell apoptosis; qPCR was performed for detecting the expressions of SCF, ICAM-1, and VCAM-1 mRNAs, and ELISA was used to detect the expressions of IL-3 and GM-CSF. RESULTS: The white blood cell count was significantly higher in LIPUS group than in the control group ( < 0.05). Histopathological examination of the bone marrow revealed significantly increased hematopoietic tissue in LIPUS group ( < 0.05). Flow cytometry demonstrated an obviously lower cell apoptosis rate in the bone marrow in LIPUS group than in the control group ( < 0.05). Compared with those in the control group, the mRNA expression levels of ICAM-1 and VCAM-1 as well as the protein levels of IL-3 and GM-CSF were significantly increased in LIPUS group ( < 0.05). CONCLUSIONS LIPUS can alleviate the hematopoietic damage after combined chemotherapy with doxorubicin with cyclophosphamide probably by increasing the expressions of ICAM- 1, VCAM-1, IL- 3, and GM-CSF.
Animals ; Bone Marrow ; Cyclophosphamide ; Doxorubicin ; Hematopoietic Stem Cell Transplantation ; Rats ; Ultrasonic Waves