Studying the damages of mouse retina induced by 2,5-hexanedione / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To study toxic effects of 2,5-hexanedione (2,5-HD) on pathology and lipid peroxidation in mouse retina.</p><p><b>METHODS</b>Forty-eight mice were randomly divided into blank control group (12 mice), negative control group exposed to normal solution (12 mice) and group exposed to 2,5-HD for 2. 4 and 8 weeks, respectively (24 mice) by intraperitoneal injection (2.5% 2,5-HD) at the dose of 400 mg/kg. The pathological changes of mouse retina were examined under light microscope. The activity of superoxide dismutase (SOD) and the level of malondialdehyde (MDA) in mouse retina were detected.</p><p><b>RESULTS</b>The retinal structure in the blank and negative control groups was normal. In mice exposed to 2,5-HD for 8 weeks, the swelling of outer and inner segments and disorder arrangement of the segments without clear boundary were found. The staining of outer plexiform layers was uneven and the irregular loose structure appeared. The hyperchromatic pyknotic and necrosis nuclei were presented in ganglion cells layer. Compared with the control and blank groups, the activities of SOD gradually and significantly reduced and the concentrations of MDA increased in group exposed to 2,5-HD (P < 0.05).</p><p><b>CONCLUSION</b>2,5-HD can induce the injury of retina tissues of mice, which may be associated with the lipid peroxidation.</p>

The application of single-genome amplification and sequencing in genomic analysis of an attenuated EIAV vaccine / 病毒学报

Our previous studies found that the Chinese attenuated EIAV vaccine was composed of a pool of quasispecies, which showed a complicated diversity called "multi-species". Further determining the viral composition of these species in the vaccine should improve the identification of predominant viruses in the vaccine and facilitate the analysis of in vivo evolution of EIAV and the vaccine. In this study, the comparison of fidelities in amplifying and sequencing the V3 to V5 fragment of EIAV envelope gp90 gene by either a single-genome amplification (SGA) approach or the traditional RT-PCR (bulk PCR) was performed. Results revealed that the diversities were 1.84% and 1.88% for SGA- and bulk PCR-derived sequences, respectively. Futher analysis revealed that beside the sequences highly homologous to those derived by the bulk PCR, nine of 73 sequences derived by SGA contained a deduced amino acid domain that was identical to the corresponding domain in the virulent strain LN40. In addition, sequences with deletion of one predicted amino acid residual was detected by using SGA The presence of these less populated sequences provided additional evidence for the "multi-species" hypothesis for the action mechanism of the EIAV vaccine. Furthermore, based on the analysis of sampling bias, Our results that the difference in copy number of each viral specie in the pool of quasispecies resulted in the inefficiency to amplify viral sequences that were in low population by bulk PCR. Therefore, the sequences amplified by bulk PCR could not correctly represent the composition of quasispecies. As an approach based on the amplification and sequencing single isolated genome, SGA significantly improved the weakness of bulk PCR and appeared its advantage in analysis of EIAV genome composition with high variety.

A multi-center study of a modified open trocar first-puncture approach in 17 350 patients for laparoscopic entry / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Laparoscopic entry is of primary importance in laparoscopic surgery because of its potential association with serious complications such as visceral and vascular injuries. There are several approaches now available for laparoscopic entry. The present study reported a modified open trocar first-puncture approach (Yan's open technique) and validated its safety and practicability in a multi-center research.</p><p><b>METHODS</b>The study was performed in seven gynecological endoscopy centers for 8 successive years from September 1998 to March 2006 involving 17 350 patients, who received the modified open trocar first-puncture approach developed by Dr. LIU Yan as the study group (MOT group). The "Yan's open technique" is the umbilical incision with a scalpel and then a 10-mm trocar entry into the abdominal cavity through direct trocar puncture or insertion of the cannula sheath via the opened umbilicus under no resistance. Another 4570 patients received the traditional Veress needle puncture as the control (VN group). The first puncture procedures of both groups were performed by 28 experienced gynecologic laparoscopists and 170 learners.</p><p><b>RESULTS</b>In MOT group, the successful achievement rate (AR) of first puncture was 99.99% (17 348/17 350), including smooth manipulation in 17 326 cases and unsmooth manipulation in 22 cases. The remaining two cases failed. First-puncture associated complications occurred in two cases (0.01%). In VN group, the successful AR of first puncture was 99.89% (4565/4570), including smooth manipulation in 4542 cases and unsmooth manipulation in 23 cases. The remaining five cases failed. First-puncture associated complications occurred in four cases (0.09%). There was no significant difference in the successful AR between the experienced gynecologic laparoscopists of the two groups (100% vs 100%, P > 0.05), but the difference was significant between the learners of the two groups (99.98% vs 99.81%, P < 0.05). The complication rate of VN group was significantly higher than that of MOT group (0.09% vs 0.01%, P < 0.05).</p><p><b>CONCLUSIONS</b>Compared with the traditional Veress needle puncture, the modified open trocar first-puncture is easier to follow, especially for learners. In addition, it can avoid possible Veress needle-associated injuries. Opening the umbilical hole for the sake of minimizing or zeroing puncture resistance is a safer and more practicable maneuver for laparoscopic entry.</p>

Investigation of Microcystin-LR Pollution in Large Reservoirs in Taiyuan / 环境与健康杂志

Objective The aim of this paper is to know about the pollution of microcystin-LR(MC-LR)in Fenhe First reservoir and Fenhe Second reservoir in Taiyuan and provide reference for making the policy of prevention microcystin-LR pollution.Methods During the low water period(May,2005)and common period(Oct,2005),5 liter water was sampled in the entrance,the center and the exit in Fenhe First reservoir and Fenhe Second reservoir respectively.The concentrations of MC-LR in two reservoirs were determined by the high-performance liquid chromatography(HPLC).Results The average concentration (0.875 ?g/L)of MC-LR in low water period was 3 time of that(0.283 ?g/L)in common period in Fenhe First reservoir.The average concentration(0.815 ?g/L)of MC-LR in low water period was 17 time of that(0.048 ?g/L)in common period in Fenhe Second reservoir.The level of MC-LR in the entrance was the highest,that in the exit was the lowest,that in the center was middle. The concentration of MC-LR of the entrance in low water period was more than the MC-LR limit(1 ?g/L)in Life drinking water hygienic guide(2001).Conclusion MC-LR pollution has been found in Fenhe First reservoir and Fenhe Second reservoir and the pollution is serious in low water period.

Caspase-12 expression and activation in the pathogenesis of acute hepatic failure induced by lipopolysaccharide and D-galactosamine / 中华肝脏病杂志

<p><b>OBJECTIVE</b>To study the role of caspase-12 expression on hepatocyte apoptosis in an experimental model of acute hepatic failure (AHF).</p><p><b>METHODS</b>A mouse experimental model of AHF was developed by intraperitoneal injection of lipopolysaccharide (LPS) and D-galactosamine (D-Gal). Hepatocyte apoptosis was examined by DNA agarose gel and liver pathology. Caspase-12 mRNA expression in liver was detected by reverse transcriptase PCR (RT-PCR) method. The expression of caspase-12, GRP78 proteins in livers was determined by Western blot.</p><p><b>RESULTS</b>Caspase-12 mRNA expression in the livers increased significantly from 5 to 7 hours after administration of LPS and D-Gal. Typical manifestation of hepatocyte apoptosis appeared at 5 hours after the drug administration. After 5 hours the level of serum ALT and AST were remarkably increased, and they reached the peak at 7 hours. The expression of procaspase-12 protein decreased obviously at 7 hours. Seven hours after the drug administration, hepatocyte apoptosis and necrosis both started. The marker of endoplasmic reticulum (ER) stress, Bip/GRP78 was activated during the development of hepatocyte apoptosis. The level of Bip/GRP78 protein was gradually increased at 5 hours after the drug induction.</p><p><b>CONCLUSION</b>Hepatocyte apoptosis plays an important role in the pathogenesis of AHF. Caspase-12 induced ER stress involves in hepatocyte apoptosis. It suggests that inhibition of caspase-12 activation might be a potential strategy in the treatment of AHF in the future.</p>

Inhibition of mouse hepatocyte apoptosis by anti-caspase-12 small interfering RNA / 中华肝脏病杂志

<p><b>OBJECTIVES</b>To study the inhibition of primary mouse hepatocyte apoptosis by small interfering RNA (siRNAs) against caspase-12.</p><p><b>METHODS</b>The Balb/c mouse primary hepatocytes were isolated in situ with two-step liver perfusion with 0.5 g/L collagenase type IV, and apoptosis were induced with 4 micromol/L thapsigargin (TG). The three kingds of siRNAs targeting different gene sites (130, 214, 521) were synthetized chemically. The single-stranded RNAs were annealed to produce double-stranded siRNAs, then the mouse primary hepatocytes were transfected by oligofectamine package. The inhibition of caspase-12 was analyzed with RT-PCR and Western-blot. The viable hepatocytes following the induction of apoptosis were evaluated with MTT.</p><p><b>RESULTS</b>All the three kinds of siRNAs could obviously inhibit normal mouse hepatocyte caspase-12 mRNA. The siRNA (214) were more effective than the other two when the concentration was 100 nmol/L. The caspase-12 mRNA expression was inhibited by 52.08%, while that of siRNA (521) was 30.73% (t=4.30, P <0.05). However when the concentration was 200 nmol/L, the inhibitions were similar (88.07%, 86.22% and 89.41% respectively). siRNA (214) could downregulate the expression of apoptotic hepatocytes procaspase-12 by 51.43% ( t=4.30, P <0.01). Contrasted with apoptotic hepatocytes, the cell activity, which was analyzed with MTT, increased by 48.76% (t=2.23, P <0.01).</p><p><b>CONCLUSION</b>siRNAs could effectively downregulate the expression of caspase-12 at mRNA and protein levels and prevent mouse primary hepatocytes from apoptosis.</p>