Objective: To investigate the role of human umbilical vein endothelial cells (HUVEC) in supporting hematopoiesis and the expansion of hematopoietic stem/progenitor cells in vitro. Methods: According to the fact that HUVEC supernatant has colony stimulating activity shown by methylcellulose colony-forming assay and HUVEC can maintain the survival of mononuclear cells for at least four weeks in vitro, CD34+ cells from umbilical cord blood were seeded with (HUVEC group) or without (control group) HUVEC monolayer. Every week cells were collected and counted, the frequency of CFU-GM was measured by using methylcellulose colony-forming assay, and the percentage of CD34+ and CD41a+ cells was measured by flow cytometry. Results: In control group，all the CD34+ cells died in two weeks. However, in HUVEC group,most nucleated cells and CD34+ cells were expanded by 68.1±14.8 fold and 6.6±1.4 fold，respectively at the third week while CFU-GM expansion reached its peak (5.7±2.1 fold) at the week 2. Moreover, the percentage of CD41a+ cells was enhanced significantly, reaching a maximum (15.6%) at the week 3. Conclusions:HUVEC can support hematopoiesis in vitro and expand the hematopoietic progenitor cells and CD41a+ cells in direct contact coculture.

OBJECTIVETo investigate the effects of catecholamine hormone on the blood and brain of heroin addicts.

METHODSRats were divided into three groups and treated with the glucose (control group), the heroin (im) (heroin group), and the combination of the intramuscular injection of reserpine and heroin (reserpine group). Changes in the levels of the dopamine (DA), cAMP, and cGMP were detected by the radioimmunoassay (RIA) method in the blood and brain tissue.

RESULTSNo significant withdrawal symptoms were observed in the reserpine group. Compared with the control and heroin groups, the blood cAMP levels were increased by 35.36% and 15.53% in the reserpine group, respectively; the cAMP levels in the midbrain ventral tegmental area (VTA), prefrontal cortex (PFC), and hippocampus (Hipp) were increased by 24.08% & 8.53%, 15.66% & 8.13%, and 21.95% & 8.40%, respectively. While compared to the control and heroin groups, the DA levels of the PFC, Hipp, striatum, and nucleus accumbens (NAc) were significantly reduced in the reserpine group, decreasing by 74.09% & 82.86%, 81.06% & 82.23%, 91.62% & 86.55% and 84.35% & 90.63%, respectively. The concentrations of cGMP of the brain tissues in the reserpine group were lower than those in the control group. In addition, the neural electrophysiological testing showed that the electroencephalogram (EEG), electrocardiogram (ECG), and muscle spindle discharge diagram of rats in both the reserpine and heroin groups were apparently changed.

CONCLUSIONCatecholamine hormone plays an important role in heroin addiction.

Animals ; Brain ; drug effects ; metabolism ; Catecholamines ; physiology ; Cyclic AMP ; blood ; metabolism ; Cyclic GMP ; blood ; metabolism ; Dopamine ; blood ; metabolism ; Heroin Dependence ; metabolism ; physiopathology ; Male ; Rats ; Rats, Wistar

This study aims to construct a dynamic two-dimensional characterization technique for the hygroscopicity of traditional Chinese medicine extracts and investigate the effect of material properties of powders on hygroscopicity. The dynamic hygroscopicity-time curves of the powders were measured at 25 ℃ and 75% humidity, and the semi-equilibrium hygroscopicity time (t_1/2) and equilibrium hygroscopicity (F^∞) were derived as two-dimensional evaluation indicators. Finally, the correlation between the material properties and the hygroscopic behavior was analyzed by principal component analysis (PCA) and partial least squares analysis (PLS). The results showed that the dynamic two-dimensional characterization system of hygroscopicity constructed with 1/t_1/2 = 0.1 h^-1 and F^∞ = 15% as the center can classify the hygroscopic behavior of traditional Chinese medicine extracts into four categories: fast hygroscopicity with strong hygroscopicity, slow hygroscopicity with strong hygroscopicity, fast hygroscopicity with weak hygroscopicity and slow hygroscopicity with weak hygroscopicity. The moisture absorption was negatively correlated with D₅₀, D₉₀, ρ_b and ρ_t; the moisture absorption rate was negatively correlated with D₁₀, D₅₀, D₉₀, ρ_b, ρ_t, and positively correlated with moisture content. The hygroscopicity dynamic two-dimensional characterization indicators of Chinese medicine extracts (CMEs) constructed in this study matched with the physical properties. The method of dynamic multi-dimensional characterization technology is feasible and scientific, and the idea has strong promotional value.

Taking Duke University as an example, this article makes a comparison between the major of biomedical engineering in the Southeast University and that in American universities in term of subject direction, faculty, teaching principle and status of publishing academic papers. Through the comparison and analysis, the problems we face were explored. From the comparison and summary the future improvements in four aspects, such as strengthening the interdisciplinary among different majors, etc. so as to provide an inspiration on the future perspectives of research and teaching in biomedical engineering in China.
Biomedical Engineering ; education ; China ; Curriculum ; Education, Medical, Continuing ; Education, Medical, Undergraduate ; United States ; Universities

OBJECTIVETo construct a lentiviral vector of repressor element-1/neuron-restrictive silencer element (RE-1/NRSE) double-stranded RNA (dsRNA).

METHODSThe RE-1/NRSE cDNA containing both sense and antisense oligo DNA fragments of the targeting sequence was synthesized and cloned into the pGC-LV vector. The obtained lentiviral vector containing RE-1/NRSE dsRNA was confirmed by PCR and sequencing. A total of 293T cells were cotransfected with lentiviral vector of L-smNRSE/RE-1, pHelper 1.0, and pHelper 2.0. The titer of virus was measured based on the expression level of green fluorescent protein. The transfection efficiency of green fluorescent protein into rat mesenchymal stem cells was calculated.

RESULTSPCR and DNA sequencing demonstrated that the constructed lentivirus vector of L-smNRSE/RE-1 produced RE-1/NRSE dsRNA.The titer of the concentrated virus was 4x108 TU/m1. The virus was stably transfected into rat mesenchymal stem cells, and the infection efficiency reached 100% when the multiplicity of infection was 80.

CONCLUSIONThe lentivirus vector of RE-1/NRSE dsRNA is successfully constructed.

Animals ; Bone Marrow Cells ; Cells, Cultured ; Genetic Vectors ; Lentivirus ; genetics ; Mesenchymal Stromal Cells ; Plasmids ; genetics ; RNA, Double-Stranded ; genetics ; Rats ; Repressor Proteins ; genetics ; Silencer Elements, Transcriptional ; genetics ; Transfection

This study was designed to explore the RNA interference technique in inhibition of the expression of the mouse fibrinogen like protein 2 (mfgl2), which has been reported to be involved in the development a variety of diseases including fulminant viral hepatitis. A plasmid named p-mfgl2shRNA,complementary to the sequence of mfgl2 was constructed, while another short hairpin RNA (shRNA)which was a mutated form of the mfgl2shRNA sequences was used as a control. A plasmid named pEGFP-mfgl2 expressing the mfgl2-EGFP fusion protein was also constructed for the screening of the effect of p-mfgl2shRNA on mfgl2 expression. By cotransfection of p-mfgl2shRNA and pEGFP-mfgl2 or pcDNA3.1-mfgl2 expression construct into CHO cells or HeLa cells, the inhibition of mfgl2 expression by mfgl2shRNA was analyzed by direct observation through fluorescent microscopy, FACS, RT-PCR and immunohistochemistry staining. The experiments showed the significant inhibitory effect of p-mfgl2shRNA on mfgl2 expression at 48h post-transfection in both CHO and Hela cell lines with the inhibitory efficiency as high as 80.1%. The study demonstrated that the construct of p-mfgl2shRNA successfully interfered with the mfgl2 expression in vitro.

Objective To evaluate X-ray,CT and MRI findings of soft tissue infections in AIDS. Methods Three cases of soft tissue infections with AIDS were retrospectively analyzed by comparing the imaging findings with pathological results.All patients were performed MRI,X-ray was in 1 case,CT was in 1 case.Results Cellulitis was in 1 case:MRI showed extended thickening of subcutaneous tissues, ill-defined hypointense areas on T_1WI and hyperintensity on T_2WI,and reticular pattern on GRE. Necrotizing fasciitis was in 1 case:MRI showed obvious thickening of subcutaneous tissues and deep fasciae, abnormally increased signal intensity on T_1 and T_2WI.Fluid collections were within muscles and muscles interval on fat-suppressed T2 WI.Tuberculosis was in 1 case:CT demonstrated multiple low density areas in the subcutaneous tissues and clear peripheral rim enhancement.MRI appeared hypointense on T_1WI and hyperintensity on T_2WI,and peripheral rim enhancement following gadolinium injection.Conclusion Infections of soft tissue are common complication in patients with AIDS,radiology is important in early diagnosis and treatment planning in this population.

A reliable, low-cost, and highly efficient nonviral gene delivery system using lower molecular weight polyethylenimine (LMW-PEI) is provided. LMW-PEI was linked to an expressing plasmid with green fluorescence protein gene (gfp), the transfection activity mediated by PEIs were examined in the CM7721 cell line and the skin tissue of mouse, respectively. The cytotoxicity of PEIs, the localization and continuance time of gfp expressed in the skin tissue of mouse were also studied. Results showed that the transfection rate of gfp mediated by LMW-PEI in the CM7721 cell line was about 55% . However, with the increasing PEI molecular weight, the cytotoxicity of PEI increased, but its transfection activity decreased. The tissue transfection results showed that LMW-PEI induced a significant expression of the gfp in the cells of hair vesicle and sweat gland of mouse skin tissues following transfection of 24 h, and the expression of gfp lasted 7 - 9 d. When the tissue of mouse was treated with retinoic acid and nitrogenous ketone, respectively, gfp was transferred to the granule layer of mouse skin tissue. The LMW-PEI described here is a new, highly efficient vector; it would be a useful nonviral vector for gene delivery technology.
Animals ; Cell Line, Tumor ; Cell Survival ; drug effects ; Gene Transfer Techniques ; Green Fluorescent Proteins ; genetics ; metabolism ; Immunohistochemistry ; Mice ; Microscopy, Fluorescence ; Molecular Weight ; Plasmids ; chemistry ; genetics ; Polyethyleneimine ; chemistry ; toxicity ; Skin ; metabolism

Acquired Immunodeficiency Syndrome ; Blood Donors ; China ; HIV Infections ; Humans ; Prejudice ; Rural Population

Objective To analyze the pathogenic epidemiological characteristics of acute lower respiratory tract infection(ALRTI) in children in Gansu Province from 2012 to 2015. Methods The surveillance data of 458 children infected with ALRTI in 10 sentinel hospitals in Gansu province from 2012 to 2015 were collected, and infection status and epidemiological characteristics of each virus and bacteria were analyzed by descriptive study methods. Results The male to female ratio of the 458 children with ALRTI was 1.81:1, and the positive detection rate of the virus was 33.62%（95% CI：29.28%-37.97%), among which the positive detection rate of respiratory syncytial virus was the highest (12.23%).The positive detection rate of bacteria was 24.84%（95% CI：20.04%-29.65%),among which the positive detection rate of streptococcus pneumoniae was the highest (18.47%).There was significant no difference in the positive detection rate of virus and bacteria between children of different genders (P>0.05).There was significant no difference in the positive detection rate of virus among children of different age groups ( 2=5.980,P=0.050), but the positive detection rate of bacteria was different ( 2=12.078,P=0.002).Positive detection rates of virus infection and bacterial infection were different in distinct seasons (all P<0.05). By using logistics regression analysis, season, age and sentinel hospital were the influencing factors of ALRTI virus infection in children (all P<0.05), and sentinel hospital and years were the influencing factors of ALRTI bacterial infection in children (all P<0.05). Conclusion Respiratory syncytial virus, influenza virus and parainfluenza were the main causes of ALRTI virus infection in children aged 0-14 years in Gansu province, and the main bacterial infections were streptococcus pneumoniae and haemophilus influenzae, the number of virus infection was more than that of bacterial infection. Viral and bacterial infection had the same peak incidence.