Effect of reactive oxygen species on 1,4-benzoquinone-induced mitophagy / 预防医学

Objective To investigate whether the metabolite of benzene, 1, 4-benzoquinone (1, 4-BQ) , can activate PINK1/Parkin-mediated mitocphagy and the role of reactive oxygen species (ROS) in 1, 4-BQ induced mitophagy in vitro. Methods Human promyelocytic leukemia cells HL60 were used as the test cells, and were divided into control group, 1, 4-BQ group (10 μM 1, 4-BQ treated cells for 24 h), NAC group (5 mM antioxidant N-acetyl cysteine treated cells for 24 h) and 1, 4-BQ+NAC group (5 mM NAC preincubated for 1 h prior to the treatment with 10 μM 1, 4-BQ for 24 h) . The ultra structure of the cells were observed by transmission electron microscopy (TEM), and the expression of mitophagy related protein LC3, PINK1 and Parkin were detected by Western blot, and the intracellular ROS content was determined by DCFH-DA staining. Results The mitochondria in the control group showed a normal rod-shaped structure with clear mitochondrial cristae, while in the 1, 4-BQ group, the mitochondria showed a swollen structure with less mitochondrial cristae, and typical double-membrane mitophagosomes were observed. LC3-Ⅱ/LC3-Ⅰ ratio, the expression of PINK1, Parkin protein and ROS content in 1, 4-BQ group were increased compared with the control group (P <0.05) , and this increase was markedly blocked by the co-treatment of 1, 4-BQ and NAC (P <0.05) . Conclusion The 1, 4-BQ can induce PINK1/Parkin-mediated mitophagy and ROS plays a significant role in 1, 4-BQ-induced mitophagy.

Expression and significance of HIF-1 α and VEGF in rats with diabetic retinopathy

OBJECTIVE@#To investigate the expression of hypoxia inducible factor-1α (HIF-1α) and vascular endothelial growth factor (VEGF) in diabetic retinopathy (DR) rats and its effect on the DR occurrence and development.@*METHODS@#A total of 120 SD rats were randomly divided into trial group and control group with 60 in each. STZ i.p. was used in the trial group to establish the DM model, citrate buffer salt of same amount was used i.p. to the control group. 1, 3 and 6 months after injection, respective 20 rats were sacrificed in each group to observe expression of HIF-1α and VEGF in the rat retina tissue at different time points.@*RESULTS@#Expression of HIF-1α and VEGF were negative in the control group; expression of HIF-1α and VEGF protein in retinal tissue were weak after 1 month of DR mold formation. It showed progressive enhancement along with the progression in different organizations, differences between groups were significant (P<0.05).@*CONCLUSIONS@#Expressions of HIF-1α and VEGF were correlated with disease progression in early diabetic retinopathy. Retinal oxygen can induce over-expression of HIF-1α and VEGF. It shows that HIF-1α and VEGF play an important role in the pathogenesis of DR.

Influence of gastric bypass surgery on hepatic gluconeogenesis in type 2 diabetic Goto Kakizaki rats / 中华胃肠外科杂志

<p><b>OBJECTIVE</b>To investigate the influence and significance of gastric bypass surgery on hepatic gluconeogenesis in type 2 diabetic Goto Kakizaki(GK) rats.</p><p><b>METHODS</b>Forty GK rats were randomly divided into Roux-en-Y gastric bypass group(group A) and sham operation group(group B). Differences in glucose tolerance experiment(OGTT) at preoperative and postoperative 1, 2 and 4 weeks were compared and weight was recorded. Glycated hemoglobin levels were measured preoperatively and 4 weeks postoperatively. The animals were sacrificed 4 weeks after surgery and liver tissues were harvested to detect the relative expression of mRNA and protein of glucose 6 phosphatase(G-6-P) and phosphoenol pyruvate kinase(PEPCK) with RT-PCR and Western blot.</p><p><b>RESULTS</b>Fasting blood glucose levels were 6.5, 4.9, and 4.7 mmol/L in group A, and were 10.3, 10.4, and 12.5 mmol/L in group B, and the differences between two groups were statistically significant(P<0.05). The blood glucose level at 2 h after stomach lavage were 8.3, 6.4 and 5.5 mmol/L in group A, and were 21.4, 23.8 and 24.7 mmol/L in group B at postoperative 1, 2, 4 weeks, and the differences between two groups were statistically significant(P<0.05). The glycosylated hemoglobin at postoperative 4 weeks was(6.8±1.0)%, significantly lower than that in group B[(7.9±0.8)%, P<0.05]. Hepatic G-6-P and PEPCK mRNA relative expression at postoperative 4 weeks was reduced by 21.0% and 25.9% respectively as compared to group B, and the protein expression reduced as well. Immunohistochemistry showed that hepatic glycogen sedimentary in group A increased significantly.</p><p><b>CONCLUSION</b>The relative mRNA and protein level of key enzymes of hepatic gluconeogenesis are significantly decreased after Roux-en-Y gastric bypass surgery and hepatic gluconeogenesis is reduced, which may be a potential mechanism of the decrease of blood glucose.</p>

mRNA expression and methylation status of p15 promoter in mouse bone marrow cells exposed to 1,4-benzoquinone / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To detect the expression and the CpG island methylation status of tumor suppressor gene p15 after exposure to 1,4-benzoquinone (1,4-BQ) in primary cultivated C57BL/6J mouse bone marrow cells in vitro.</p><p><b>METHODS</b>The mouse bone marrow cells were isolated in vitro. The effect of 0, 0.1, 1, 5, 10, 20, and 40 µmol/L 1,4-BQ on cell viability (CKK-8) was detected. 0, 0.1, 1, 10 µmol/L 1,4-BQ were used to intoxicate the mouse bone marrow cells for 24 h; Real-time PCR was employed to analyze the mRNA expression level of p15; The bisulfite sequencing PCR (BSP) was used to look into the methylation status of CpG islands in p15 promoter region.</p><p><b>RESULTS</b>1,4-BQ exhibited dose-dependent toxicity to mouse bone marrow cells, and the LC(50) was 8.3 µmol/L (95%CI: 4.6 - 10.6 µmol/L). The mRNA expression of p15 in 10 µmol/L group was only equivalent to 43% of control group. Compared with control group, the decrease of p15 mRNA expression in1 and 10 µmol/L concentration were obvious, and the differences had statistical significance (P < 0.05 or P < 0.01). BSP sequencing results were same between the exposure groups and control group, the 56 CpG sites on CpG islands remained in the state of unmethylated.</p><p><b>CONCLUSION</b>mRNA expression of p15 gene decreases after exposure to 1,4-BQ, but the CpG islands methylation status in promoter is not affected, suggesting that methylation does not participate in 1,4-BQ-mediated p15 gene expression decrease, other effect mechanisms still need to be investigated.</p>

Sequencing of mitochondrial DNA CO II gene in carrion-breeding flies and larvae in Zhengzhou / 法医学杂志

OBJECTIVE@#Using CO II sequences to identify common species of carrion-breeding flies and larvae.@*METHODS@#flies and larvae were collected on the corpses of rats in Zhengzhou district, DNA was extracted, CO II sequences were amplified and sequenced. Clustalx and MEGA 4.0 software were used to analyze the gene sequences and to construct the phylogenetic trees.@*RESULTS@#There was no significant gene difference between adults and larvae. COII gene sequences could be used to identify Boettcherisca peregrina, Aldrichina grahami and Lucilia illustris but they could not distinguish Lucilia cuprina from the Lucilia sericata because of their close evolutionary distance and single nucleotide polymorphisms in aldrichina grahami and Lucilia illustris populations were found.@*CONCLUSION@#CO II sequence of mtDNA in Zhengzhou district can be used effectively to identify some common species of carrion-breeding fly. The method is simple and accurate.

Effect of 90 percentage portal branch ligation on liver regeneration and expression of metalloproteinase and tissue inhibitors of metalloproteinases in rats / 中华肝脏病杂志

<p><b>OBJECTIVE</b>To investigate the effect of 90% portal branch ligation on liver regeneration and expression of metalloproteinases and tissue inhibitors of metalloproteinases in rats.</p><p><b>METHODS</b>Ninety-six SD rats were randomly divided into Sham-PBL group and portal vein branches ligation group. The weight of both ligated and unligated lobes of liver were measured at post operation day (POD) 0.5, 1, 3, 5, 7, 14, 21 and 28. The morphological changes of the non-ligated liver lobes were observed by microscope. The expression of PCNA, MMP2, MMP9 and TIMP2 of the non-ligated liver lobes were studied by immunohistochemistry.</p><p><b>RESULTS</b>1) 95.8% rats survived from the ligation of 90% portal branch. Hepatic lobe at the ligated side diminished progressively after ligation, whereas the lobes of the unligated side underwent compensatory regeneration. The ratio of non-ligated lobes weight to the whole liver increased slowly within 1d, speeded up significantly during 1-5d period, increased slowly after POD5, and got the plateau stag at POD7; 2) PCNA index were markedly increased within POD 0.5-3 (P < 0.01). It reached the peak at POD5 and decreased slightly at POD7, but still higher than Sham-PBL group level, then gradually returned to normal. 3) The expression of MMP2,MMP9 and TIMP2 in the non-ligated liver lobes were markedly increased at 1d. It reached the peak at POD7 and gradually returned to normal within POD7-28. 4) The MMP2 and PCNA in liver had a positive correlation at POD 0.5, 1, 5, 7, 14. The expressions of MMP9 and PCNA had a positive correlation at POD 0.5, 1, 7, 21.</p><p><b>CONCLUSION</b>The expressions of TIMP2 and PCNA had a positive correlation at POD1, 7, 14, 21. The expression of MMP2, MMP9 and TIMP2 of the non-ligated liver lobes is markedly increased at POD1. It reaches the peak at POD7, and dropped to normal level gradually. The expressions of MMP2, MMP9 and TIMP2 and PCNA were correlated in 90% portal branch Ligation rats. The expression of MMP2,MMP9 and TIMP2 may play a pivotal role in liver regeneration.</p>

Interaction between warfarin and bovine serum albumin detected by spectrometry / 药学学报

The interaction between warfarin and bovine serum albumin (BSA) under pseudophysiological conditions was investigated by UV-Vis absorption spectrometry and spectrofluorimetry. The quenching mechanism of BSA by warfarin was discussed. It showed that the quenching process was a dynamic quenching, and the quenching constants were 6.05 x 10(4) L x mol(-1) at 16 degrees C and 6. 14 x 10(4) L x mol(-1) at 37 degrees C, separately. Based on the Förster theory of non-radiative energy transfer, the energy transfer efficiency and the distance of BSA to warfarin were calculated, which was 0.37 and 3.15 nm, respectively.

Dynamic observation of brainstem auditory evoked potential and pathological changes of the brain after closed brain injuries in rats / 法医学杂志

OBJECTIVE@#To investigate the dynamic experiences of pathological changes in brain and the injured role of brainstem auditory evoked potential (BAEP) after closed Mild Traumatic Brain Injury (MTBI) in rat.@*METHODS@#A closed diffuse brain injury model was successfully produced in rat by hit the parietal bone with a spring-droved steel stick. The auditory brainstem response evoked by click at 50Hz stimulating frequency were recorded at pre-trauma, 15 min and 1, 3, 6, 12 h and 1, 2, 4, 7, 10, 14, 21 d after brain injury. The pathological changes of brain were observed under light microscope and the brain edema was detected by wet weight/dry weight rations.@*RESULTS@#The I-V, III-V of BAEP wave inter peak latency (IPL) in MTBI group increased immediately in 15 minutes after injury. The III, V wave peak latency (PL) and I-V, III-V wave IPL became longer than the pre-trauma level in 6, 12 h post-injury (P<0.05). The III, V wave PL and I - III, I - V, III - V wave IPL became longer than the pre-trauma level in 1, 2 d after injury (P < 0.001), the BAEP retuned to normal level in 14 d after brain injury. At 15 minutes after injury, the water content in brain increased and met its peak in 1 d, decreased gradually in 4 d, then decreased slowly and returned to normal level in 10 d after injury.@*CONCLUSION@#The regular changes of BAEP could be an objective tool for evaluating hearing dysfunction after closed mild diffuse traumatic brain injury.

To estimate early postmortem interval by investigating changes of rats' gastrocnemius excitability / 法医学杂志

OBJECTIVE@#To investigate the changes of excitability of rats' gastrocnemius after rats were died from mechanic asphyxia, so as to make an objective evidence for estimating of the early postmortem interval.@*METHODS@#After rats were sacrificed by mechanic asphyxia, the reaction of rats' gastrocnemius to variable electric stimulation at different period after death were recorded by electricphysiological method.@*RESULTS@#Changes in the properties of excitable tissue to electric stimulate in rats' gastrocnemius after mechanic asphyxia seems to be well correlated with the early postmortem interval and appeared a linear relation in certain period.@*CONCLUSION@#The regular changes of excitability in muscle might be a useful means for estimating of early postmortem interval.

Expression of c-fos protein after muscle contusion in experimental rats / 法医学杂志

OBJECTIVE@#To study the relationship between the expression of c-Fos protooncogene and skeleton muscle contusion of rats, and to search for a sensitive marker of timing for skeleton muscle contusion.@*METHODS@#Fifty Sprague-Dawley rats were randomly distributed into control group and experimental groups. The expression of c-fos was microscopically observed by immunohistochemical method.@*RESULTS@#With the time prolonged the c-fos positive intensity and area were increased. Positive expression of c-fos protein appeared at 15 min after skeleton muscle contusion, and reached to the peak at 1h after skeleton muscle contusion, then decreased gradually and returned to the normal level on 1d after skeleton muscle contusion.@*CONCLUSION@#The detection of the expression of c-fos protein could be a sensitive marker for timing skeleton muscle contusion.

Learning curve of laparoscopic resection for rectal cancer / 南方医科大学学报

<p><b>OBJECTIVE</b>To evaluate the surgical outcomes of laparoscopic resection for rectal cancer and to investigate how surgeons without previous training of laparoscopic cholecystectomy(LC) can quickly learn laparoscopic resection for rectal cancer.</p><p><b>METHODS</b>Clinical data of 105 cases of laparoscopic rectal resection performed by a group of surgeons without previous training of LC were reviewed. The cases were divided equally into 3 groups (groups A, B and C) according to the sequence of the operations. The operating time, blood loss, lymph node harvest, length of specimen, conversion rate to open surgery, intra- and postoperative complications and hospital stay were compared between the 3 groups.</p><p><b>RESULTS</b>There were no significant differences between the 3 groups with respect to age, gender, Dukes'stage or surgical approach (P>0.05). The operating time in group A was 196.1+/-30.3 min, significantly longer than that in group B (164.8+/-22.7 min) and group C (158.7+/-20.9 min) (P<0.001), but the operating time did not vary significantly between groups B and C (P>0.05). The blood loss was significantly greater in group A than in groups B and C (72.4+/-21.5, 48.2+/-16.3, and 46.6+/-15.4 ml, respectively, P<0.001), but showed no significant difference between the latter two groups (P>0.05). The rate of conversion to open surgery decreased from 11.4% in group A to 2.9% in group B and group C, but the difference was not statistically significant (P>0.05). The rate of intraoperative complications declined from 17.1% in group A to 5.7% in group B and group C, showing no significant difference either. The lymph node harvest, length of specimen, and postoperative complications showed no significant variation between the 3 groups (P>0.05), but group C had significantly shorter mean hospital stay in comparison with groups A and B (P<0.001). The 35 patients in group A received the operation within a time period of 17 months (2.1 cases per month), and operations in groups B and C were done in 7 months (5 cases per month).</p><p><b>CONCLUSION</b>The learning curve of laparoscopic rectal resections is approximately 35 cases, and the surgeons without previous experience of laparoscopic cholecystectomy can learn the surgical skills after performing 35 laparoscopic resections for rectal cancer at the monthly frequency of 2.1 cases.</p>