Mechanisms and effects of PM2.5 on diseases of respiratory system: Latest findings / 西安交通大学学报(医学版)

The chemical composition of PM2.5 is extremely complex and it can carry some viruses and bacteria, gather many toxic and hazardous substances. The respiratory system is the main target organ of PM2.5 exposure and impact. There are many different kinds of respiratory system diseases, which have complex etiologies and unpredictable outcomes. Previous reports have shown that PM2.5 plays an important role in the occurrence and development of respiratory obstructive, infectious, allergic and neoplastic diseases; of which mechanisms may be related to oxidative stress, inflammatory reaction, genetic toxicity, cell apoptosis, cell autophagy and cell cycle disorders.

Protective effect of paeoniflorin against PM2.5-induced damage in BEAS-2B cells / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the protective effects of paeoniflorin against PM2.5-induced damage in BEAS-2B cells and explore the possible mechanism.</p><p><b>METHODS</b>With a factorial design, this study was performed to observe the protective effects of different doses of paeoniflorin against PM2.5-induced BEAS-2B cell growth inhibition and the effects of paeoniflorin on the contents of malondialdehyde (MDA) and intracellular reactive oxygen species (ROS) in the cell cultures.</p><p><b>RESULTS</b>Exposure to increased PM2.5 concentrations caused significant decrease in the cell survival rate (P<0.05) with a clear dose-response relationship (r=-0.759, P<0.05). Treatment of the cells with paeoniflorin significantly attenuated PM2.5-induced inhibition of BEAS-2B cell survival (P<0.05), but the effect of paeoniflorin was not dose-dependent (P>0.05). PM2.5 exposure also significantly increased the contents of MDA and intracellular ROS (P<0.05), and paeoniflorin obviously antagonized these effects of PM2.5.</p><p><b>CONCLUSION</b>Paeoniflorin can protect BEAS-2B cells from PM2.5-induced growth inhibition, and the mechanism might be related to the anti-oxidant effects of paeoniflorin.</p>

Effect of low-selenium diet on expressions of CCR7, CD206 and CD163 in the liver and kidney of rats / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the effect of low-selenium diet on the liver and kidneys of rats and explore the role of macrophage polarization into M1 and M2 phenotypes in liver and kidney injuries.</p><p><b>METHODS</b>Twenty-four rats (12 female and 12 male) were randomly divided into control group and low-selenium group and fed with normal chow (dietary selenium of 0.18 mg/kg) and low-selenium diet (dietary selenium of 0.02 mg/kg) for 109 days. After the feeding, the rats were sacrificed for HE staining to observe liver and kidney pathologies, and immunohistochemistry was performed for analyzing CCR7, CD206, CD163-positive cell numbers in the liver and kidneys.</p><p><b>RESULTS</b>The rats in low-selenium group showed severer fibrosis in the liver and kidney than the control group. In either male or female rats in low-selenium group, CCR7 and CD206 expressions in the liver were comparable with those in control group, but CD163 expression was lower than that in the control group (P<0.05 for both female and male rats). In the kidney, the proximal tubule showed a slightly higher while the distal tubule showed a slightly lower CCR7 expression in low selenium group than in the control group (P>0.05). In low-selenium group, a significantly lower CD163 expression in the distal tubule and a significantly higher CD206 expression in the proximal tubule were noted as compared with the control group (P<0.05 in both female and male rats). Compared with the control rats, the male rats in low-selenium group, but not the female rats, showed a significantly lower CD163 expression in the proximal tubule of the kidney (P<0.05); the female but not the male rats in low-selenium group show a higher CD206 expression in the distal tubule (P<0.05).</p><p><b>CONCLUSION</b>Low-selenium diet can cause liver and kidney fibrosis in rats and may inhibit macrophage activation into the M2 phenotype.</p>

Survivin expression in midline T-cell lymphoma in relation to Epstin-Barr virus infection / 中国实验血液学杂志

To investigate the expression of survivin gene and its relationship with Epstin-Barr virus (EBV) infection in midline T-cell lymphoma (MTL), immunohistochemistry staining method was used to examine the expression of survivin and EBV-latent membrane protein (LMP-1) in the 41 cases. In situ hybridization (ISH) was used to detect EBV-encoded RNA (EBER1/2). The results showed that the expression of survivin was positive in 26 cases of midline T-cell lymphoma, but no positive was detected in 10 cases of reactive lymphoid tissues. The positive expression ratio of survivin was 12.5% in cases of MTL with low grade of malignancy, and was 75.76% in cases of MTL with middle and high grades of malignancy, the significant difference was found between these two groups (chi(2) = 8.55, P < 0.01). Positive expression ratios of EBER1/2 and LMP-1 were 70.73% and 41.46% respectively. Survivin expression was not significantly different between EBER1/2 positive and negative cases (P > 0.05). It is concluded that survivin expression is up-regulated in MTL, and survivin positive expression rate is associated with the degree of malignancy. Survivin may play a role in the pathogenesis of the MTL by influencing cell apoptosis. EBV infection is not significantly associated with survivin expression in the MTL.

The effects of adenovirus-mediated human COX-2 antisense RNA on the growth of hepatocellular carcinoma / 中华肝脏病杂志

<p><b>OBJECTIVE</b>To investigate the relationship between the expression of COX-2 and liver cancer and construct a recombinant adenovirus encoding human COX-2 antisense RNA, and then to investigate its effects on liver cancer cell proliferation.</p><p><b>METHODS</b>The expression of COX-2 in 34 cases of hepatocellular carcinoma and in SMMC-7402 and SMMC-7721 cell lines was studied by using immunohistochemical techniques. The shuttle plasmid encoding anti-sense COX-2 was constructed by using cloning COX-2 cDNA fragment in the reverse direction into the pHCMVSPIA. Then the plasmid pJM17 and the shuttle plasmid were co-transferred into 293 cells with lipofectamine for homologous recombination to acquire recombinant adenovirus (Ad-AShcox-2), which was confirmed by PCR. Human hepatocellular carcinoma cell lines SMMC-7402 and SMMC-7721 were transduced in vitro. The cell apoptosis and cell cycle were analyzed by flow cytometry. The cell proliferation was determined by colony-forming efficiency.</p><p><b>RESULTS</b>We observed COX-2 expression in 82.4% of the hepatocellular carcinomas and SMMC-7402 cell line, but no COX-2 expression in the SMMC-7721 cell line. In addition, the recombinant adenovirus encoding anti-sense COX-2 fragment Ad-AShcox-2 was obtained with a titer of 1.06 x 10(12) PFU/ml. Ad-AShcox-2 reduced the expression of COX-2 and enhanced the percentage of cells into G1/G0 phase in the SMMC-7402 cell line. The difference of apoptotic index between the Ad-AShcox-2 group and the control group was statistically significant in SMMC-7402 but not in SMMC-7721. Similarly, colony-forming rates of SMMC-7402 and SMMC-7721 cell lines after Ad-AShcox-2 being transferred were (2.7+/-0.94)% and (33.6+/-4.24)%, respectively.</p><p><b>CONCLUSION</b>By reducing the expression of COX-2 in hepatocellular carcinoma cells with the expression of COX-2, the cells could be inhibited.</p>

Experimental study of contralateral testicular changes after unilateral testicular torsion in rats / 中华男科学杂志

<p><b>OBJECTIVE</b>To study the changes of the contralateral testicular histology and germ cell apoptosis after unilateral testicular torsion (UTT) and to determine whether the contralateral testis is injured or not.</p><p><b>METHODS</b>Sixty SD male rats were divided into control group (12 rats) and experimental group(48 rats). The former underwent sham operation of the left testis under general anaesthesia. The latter underwent left testis torsion(720 degrees) for 6 h, and then 4 of them were sacrificed and the other 44 were subdivided into the torsed testis untwisted group (22 rats) and the torsed testis removal group (22 rats), 7-8 rats were sacrificed and both testes (twisted and untwisted) were removed 1 day, 1 week and 4 weeks after surgery. All testes underwent histological and germ cell apoptosis examination.</p><p><b>RESULTS</b>There were significant histological changes in the contralateral testis, and the germ cell apoptosis was increased greatly in the contralateral testis.</p><p><b>CONCLUSIONS</b>UTT can cause contralateral testicular injury, whose mechanism may be related to reperfusion, and torsed testis removal can prevent or reduce damage to the contralateral testis.</p>

A randomized controlled clinical study of lower-dose peginterferon alfa-2b in combination with ribavirin in the treatment of chronic hepatitis C / 中华传染病杂志

Objective To compare the effecacy and safety of lower dose peginterferon alfa-2b plus ribavirin versus standard interferon alfa-2b plus ribavirin for treatment of chronic hepatitis C in China.Methods 192 patients with chronic hepatitis C were assigned peginterferon alfa-2b 0.5?g/kg each week plus ribavirin 750～1050 mg/d or standard interferon alfa-2b 3 MIU TIW plus ribavirin 750～1050 mg/d for 48-week treatment and 24-week fellow-up.Results The sustained virological response (SVR)rate in lowe-dose peginterferon alfa-2b plus ribavirin group was 53.8%,and the SVR rate in standard interferon alfa-2b plus ribavirin was 58.1%.The SVR was similar between the two treat- ment group(P=0.966 for both comparisons).The adverse event rate was higher in peginterferon al- fa-2b plus ribavirin group than in standard interferon alfa-2b plus ribavirin group(P=0.033 for both comparisons),but there was no new or unique adverse event in related to pegylation of interferon alfa-2b. Conclusion The effecacy and safety was similar between lower-dose peginterferon alfa-2b plus ribavirin and standard interferon alfa-2b plus ribavirin for treatment of chronic hepatitis C.

Immunophenotypic Features of NK/T Cell Lymphoma in Children and Its Association with Epstein-Barr Virus / 实用儿科临床杂志

Objective To study the immunophenotypic features of NK/T cell lymphoma in children and its association with Epstein-Barr virus (EBV) infection. Methods Five cases of children′s NK/T cell lymphoma were studied. CD45RO, CD3?, CD56, CD20, TIA-1 and granzyme B were detected by immunohistochemistry staining for investigating immunophenotype. The expression of EBV-latent membrane protein (LMP-1) were detected by immunohistochemistry. EBV-encoded RNA (EBER1/2) were detected by in situ hybridization (ISH). Results CD45RO, CD3?, TIA-1 and granzyme B were positive in 5 cases, CD56 was positive in 2 cases, while CD20 negative in 5 cases.EBER1/2 positive in 4 cases and LMP-1 positive in 3 cases.Conclusions NK/T cell lymphoma in children is strong associated with EBV infection,and EBV infection may play an important role in the pathogenesis of children NK/T cell lymphoma.