Protective effect of Rhubarb on newborn rats with bronchopulmonary dysplasia / 中华实用儿科临床杂志

Objective To investigate the effect of Rhubarb on bronchopulmonary dysplasia(BPD) and its potential mechanism.Methods Neonatal Sprague-Dawley rats (postnatal day 4) were exposed to 600 mL/L 02 to induce BPD.The experimental rats were randomly divided into 4 groups with 16 in each group:air + saline group,air +Rhubarb (600 mg/kg)group,and hyperoxia + saline group,and hyperoxia + Rhubarb group.The rats were sacrificed and lung tissues were obtained on day 14 and 21 after birth.Hematoxylin-easin staining was used to detect the pathomorphology of the lungs.Apoptosis of the lung tissue was detected by means of TdT-mediated dUTP nick-end labeling (TUNEL).The expression of Fas was detected by adopting Western blot.The activity of Caspase-8 and Caspase-3was detected by using spectrophotometer.Results The lung structure of rats was markedly abnormal (decreased,enlarged and simplified alveoli) after being exposed to hyperoxia at any time point.The apoptosis indexes (39.91 ± 1.91vs.10.11 ± 1.64,48.80 ± 4.51 vs.12.90 ± 3.18),the expression levels of Fas (0.47 ± 0.02 vs.0.21 ± 0.01,0.55 ±0.02 vs.0.22 ±0.01) and the activities of Caspase-8 (52.59 ± 1.23 vs.40.74 ± 1.08,60.20 ± 3.48 vs.40.39 ±2.47) and Caspsase 3 (57.17 ± 1.88 vs.42.00 ± 1.19,64.57 ± 2.79 vs.41.54 ± 1.27) were all increased in the hyperoxia + saline group compared with those in the air + saline group on day 14 and 21,and the differences were statistically significant(all P ＜ 0.001).However,compared with the hyperoxia + saline group,Rhubarb administration dramatically decreased pulmonary apoptosis index (26.49 ± 2.65 vs.22.97 ± 3.66),Fas protein level (0.27 ± 0.03 vs.0.31 ± 0.01) and the activity of Caspase-8 (32.70 ± 2.69 vs.30.66 ± 4.48) and Caspase-3 (44.94 ± 1.60 vs.44.59 ± 1.66),and the differences were statistically significant (all P ＜ 0.001).Meanwhile,lung damage after hyperoxia was significantly attenuated in the hyperoxia + Rhubarb group.Conclusion Rhubarb can reduce the hyperoxic lung injury of BPD by reducing the apoptosis of newborn rat lung tissue cells,and the mechanism may involve the apoptosis pathway of Fas.

Comparison of transfection efficiency of lymphocytes from human peripheral blood by different methods / 白血病·淋巴瘤

Objective To explore the transfection efficiency of primary lymphocytes from human peripheral blood by different methods to acquire the method with higher transfection efficiency.Methods Mononuclear cells from human peripheral blood were isolated using Ficoll-Hypaque.Cell viability was detected by Trypan blue staining.Suspending lymphocytes were sucked out and were incubated in 24-well plate after cultured in 6-well plate for 2 h.Activated lymphocytes were transfected by electroporation with plasmid(PEGFP-N1).Resting or activated lymphocytes were transfected by lentivirus vector(LVGFP) single infection or repeated infection,respectively.Green fluorescence protein (GFP) was detected under the fluorescence microscopy and percentage of positive cells was checked by flow cytometry at different time points after infection.At the same time,the effectiveness of lentivirus infection was compared under different conditions.Results Purity of mononuclear cells isolated by Ficoll-Hypaque was 95 ％ and its viability was over 95 ％.The percentage of lymphocytes obtained with a uniform shape was 90 ％-95 ％.Scattered fluorescence was observed by electroporation under the conditions of voltage 2 100 V,pulse width 10 ms,pulse number 1 for lymphocyte,while fluorescent became weaker over time and no green fluorescent was observed after transfection for 72 h.After resting lymphocytes were infected once for 48 h by lentivirus vector,green fluorescent was not found and positive cells were less than 1％.1％-5 ％ of activated lymphocytes could express GFP after single lentivirus infection and the expression levels were enhanced with concentration increasing,while 5 ％-10 ％ of activated lymphocytes showed strong green fluorescent by repeated lentivirus infection.In contrast with electroporation,the fluorescent with lentivirus infection was stronger over time.Conclusion Repeated lentivirus infection could efficiently transfect exogenous genes into activated lymphocytes for stable expression.

Effect on T cell subsets and secretion of IFN-γ and IL-17 after exposure to ⁶⁰Co lethally total body irradiation in mice / 中华血液学杂志

<p><b>OBJECTIVE</b>To investigate the effects of letherally total body irradiation (TBI) on distribution of T-lymphocyte subtypes and their cytokine expression.</p><p><b>METHODS</b>The BALB/c mice were divided randomly into ⁶⁰Co gamma rays TBI group and control group. Mice were sacrificed 7 days after irradiation. The lymphocytes in spleens, mesenteric lymphonodes, livers and bone marrow were collected and counted. Changes of CD4(+) T and CD8(+) T cell subsets as well as the expressions of IFN-γ and IL-17 were analyzed by flow cytometry.</p><p><b>RESULTS</b>(1)Compared with control group, the total number of lymphocytes in marrow, spleen, lymph node and liver distinctively decreased in TBI group [(5.34±1.14)×10⁵ vs (3.08±1.13)×10⁷, (2.10±0.54)×10⁵ vs (2.71±0.83)×10⁷, (5.89±1.07)×10⁵ vs (7.92±1.15)×10⁷ and (3.45±1.01)×10⁵ vs (7.44±0.79)×10⁶, respectively, and the significant differences were observed between two groups in each organ (P<0.05)]. (2)The level of IFN-γ produced by CD4(+) T in spleen, lymph node and liver elevated in TBI group compared to control group, which were (20.77±2.03)% vs (3.69±3.13)%, (6.28±0.46)% vs (1.11±0.17)%, (27.24±5.79)% vs (9.01±1.24)% respectively, the differences between two groups in each organ were significant (P<0.05). (3)Percentages of IFN-γ(+)CD8(+) T in spleen, lymph node and liver in TBI group increased compared to control group [(52.40±9.26)% vs (43.06±1.04)%, (33.56±5.02)% vs (21.83±4.22)%, and (44.27±8.97)% vs (19.32±3.11)%, respectively, and the differences between two groups in each tissue were significant (P<0.05)]. (4)However, IL-17A expressions in CD4(+) T and CD8(+) T cells from spleen and liver were lower than those in control group.</p><p><b>CONCLUSION</b>TBI induced the reduction of lymphocytes and the expansion of IFN-γ producing Th1 and Tc1 effector cells in mice.</p>

The role of IL-22 on thymus recovery and its function in mice following allogeneic bone marrow transplantation / 中华血液学杂志

<p><b>OBJECTIVE</b>To explore the role of IL-22 on the recovery and function of thymus from graft-versus host disease (GVHD) mice after allogeneic bone marrow transplantation (allo-BMT).</p><p><b>METHODS</b>GVHD model was established by using of recipient male BALB/c and donor male C57BL/6 mice(6-8 W) respectively. The mice were divided into normal group, GVHD with IL-22 group (BS+IL-22) and without IL-22 group (BS+PBS). Numbers of thymus cells were detected at different time points. The ratio of T cell subsets from thymus was observed by flow cytometry. Percentages of IFN-γ-producing and IL-17-producing CD4+ T or CD8+ T cells were detected.</p><p><b>RESULTS</b>The total number of thymus cells in BS+IL-22 mice [(14.6±5.1)×10⁴] was significantly higher than that in BS+PBS mice [(6.2±2.9)×10⁴] at 14 days after allo-BMT. Thymus cells in BS+IL-22 mice expanded continuously and reached at the level of normal mice, which were still higher than that in BS+PBS group. Although there was no impact on the ratio of mature CD4+ and CD8+ T cell from thymus, the percentage of immature CD4+CD8+ T cell increased obviously in mice treated with IL-22. Percentages of IFN-γ+CD4+ T cell [Th1:(2.42±0.75)%] and IFN-γ+CD8+ T cell [Tc1:(5.44±0.47)%] were up-regulated by IL-22 treatment, whereas no changes were detected in IL-17+CD4+ T cell (Th17) and IL-17+CD8+ T cell (Tc17).</p><p><b>CONCLUSION</b>IL-22 accelerates the progress of thymus recovery, and increases the IFN-γ-producing ability of thymus CD4+ and CD8+ T cells from GVHD mice.</p>

Study on the binding sites of radiosensitivity associated transcription factor in the promoter region of Ier5 gene / 中华放射医学与防护杂志

Objective To clarify the mechanism of immediate early response gene 5 (ler5)transcription induced by radiation. Methods Deletant construction, site-specific mutagenesis,electrophoretic mobility shift assay (EMSA) and chromatin immunoprecipitation (ChIP) were used to forecast the promoter region,binding sites and transcription factors of Ier5 gene in HeLa cells.Results The promoter region of Ier5 gene might be in the region of Ier5 -8 deletant ( -408 - -238 bp).The Ier5 gene had two transcription factors of GCF and NFI,and GCF had two binding sites located in the region of - 388 - - 382 bp and - 274 - - 270 bp of Ier5 promoter.The binding site of NFI was located in - 362 --357 bp of Ier5 promoter. GCF could inhibit the expression of Ier5 gene and this inhibition was diminished when the radiation dose increased. In contrast, NFI increased the expression of Ier5.Conclusions The most possible region of Ier5 promoter is from -408 to - 238 bp which has two binding sites for the radiosensitivity transcription factors of GCF and NFI that could negatively and positively regulate the expression of Ier5 respectively.

Progress on Fluorescent Probes for Thiols / 分析化学

Thiols, which are components of many proteins and simple molecules, play an important role in the cellular antioxidant defense system. The quantitative determination of thiols is important in biochemistry and clinical chemistry. Fluorescent probes, which have its apparent advantages in sensitivity and, most importantly, in imaging thiols in vivo, even in single living cells, appear to be particularly attractive. In this review, we classify the fluorescent probes based on their different reaction mechanisms with thiols and summarize the recent progresses of thiols fluorescent probes with fifty-one