Role of mitochondria in cell apoptosis during hepatic ischemia-reperfusion injury and protective effect of ischemic postconditioning

AIM: To investigate the role of mitochondria in cell apoptosis during hepatic ischemia-reperfusion injury and protective effect of ischemic postconditioning (IPC).METHODS: A rat model of acute hepatic ischemia-reperfusion was established, 24 healthy male Wistar rats were randomly divided into sham-operated group, ischemia-reperfusion group (IR) and IPC group. IPC was achieved by several brief pre-reperfusions followed by a persistent reperfusion.Concentration of malondialdehyde (MDA) and activity of several antioxidant enzymes in hepatic tissue were measured respectively. Apoptotic cells were detected by TdT-mediated dUTP-biotin nick end labeling (TUNEL) and expression of Bcl-2 protein was measured by immunohistochemical techniques. Moreover, mitochondrial ultrastructure and parameters of morphology of the above groups were observed by electron microscope.RESULTS: Compared with IR group, the concentration of MDA and the hepatocellular apoptotic index in IPC group was significantly reduced (P<0.05), while the activity of antioxidant enzymes and OD value of Bcl-2 protein were markedly enhanced (P<0.05). Moreover, the injury of mitochondrial ultrastructure in IPC group was also obviously relieved.CONCLUSION: IPC can depress the synthesis of oxygen free radicals to protect the mitochondrial ultrastructure and increase the expression of Bcl-2 protein that lies across the mitochondrial membrane. Consequently, IPC can reduce hepatocellular apoptosis after reperfusion and has a protective effect on hepatic ischemia-reperfusion injury.

Expression of nuclear factor-kappa B and target genes in gastric precancerous lesions and adenocarcinoma:Association with Helicobactor pylori cagA (+) infection

AIM:To examine the expression of nuclear factor kappaB (NF-κB) and its target genes in intestinal metaplasia (IM),dysplasia (DYS) and gastric carcinoma (GC) infected with Helicobacter pylori (H pylori) and to investigate the mechanism underlying Hpyloricytotoxin associated gene A(cag A) infection leading to gastric adenocarcinoma.METHODS: Expressions of NF-κB/p65 and its target genes:c-myc, cyclinD1 and bcl-xl were immunohistochemically examined in 289 cases of gastric biopsy and resection specimens from patients with IM, DYS and GC infected with H pylori. H pylori in the above mentioned tissues was detected by Warthin-Starry stain and rapid urease tests.IgG antibody to cagA in sera of the patients was measured by ELISA.RESULTS:The positive rates of NF-κB/p65 were significantly higher in groups with cagA of IMI-Ⅱ(28/33), IM III(48/52),DYSI(27/31), DY5 Ⅱ-Ⅲ(28/32), GC(35/40) than in groups without cagA of IMI-Ⅱ(4/17), IMⅢ(3/20), DYSI(3/20),DYSⅡ-Ⅲ(6/21), GC(10/23). The expressions of c-myc,cyclinD1, and bcl-xl were significantly higher in groups with cagA of IM Ⅲ(47/52, 49/52, 46/52), DYSⅡ-Ⅲ(29/32, 26/32,25/32) than in groups without cagA of IM Ⅲ(8/20, 7/20,5/20), DYSⅡ-Ⅲ(10/21, 8/21, 3/21), which were in conformity with the expression of NF-κB in IM Ⅲ, and DYSⅡ-Ⅲ. Asignificantly higher expression level of NF-κB/p65, c-myc,cyclinD1 and bcl-xl was detected in intestinal type GC(27/28,18/28, 22/28, 24/28) than in diffuse type GC(8/12, 3/12,3/12, 6/12), respectively.CONCLUSION: There may be two different molecular mechanisms in the occurrence of intestinal and diffuse type gastric carcinomas. Intestinal type gastric carcinoma is strongly associated with high expression of c-myc, cyclinD1 and bcl-xl through NF-κB/p65 activated by Hpylori cagA.Inhibiting the activity of NF-κB is an effective and promising way to prevent intestinal type gastric carcinoma.

NOD2 3020insC frameshift mutation is not associated with inflammatory bowel disease in Chinese patients of Hart nationality

AIM: An insertion mutation at nucleotide 3020 (3020insC) in the Caspase recruitment domain gene (CARD15), originally reported as NOD2, is strongly associated with Crohn's disease. The C-insertion mutation at nucleotide 3020 (3020inC) in the leucine-rich repeat (LRR) region results in a frameshift in the 10^th LRR followed by a premature stop codon. This truncation mutation is responsible for the inability to activate nuclear factor (NF)-κB in response to bacterial lipopolysaccharide (LPS). The present study aimed to genotype NOD2/CARD15 gene 3020insC frameshift mutation in Chinese patients with inflammatory bowel disease. METHODS: We genotyped an insertion polymorphism affecting the leucine-rich region of the protein product by the allele specific PCR in 74 unrelated patients with ulcerative colitis of Han nationality in Hubei Province of China, 15 patients with Crohn's disease and 172 healthy individuals. RESULTS: No significant differences were found in the genotype and allele frequendes of the C-insertion mutation of NOD2 gene among patients with Crohn's disease and ulcerative colitis and healthy controls. CONCLUSION: NOD2 gene 3020insC frameshift mutation is not a major contributor to the susceptibility to both Crohn's disease and ulcerative colitis in Chinese Han patients.

Effects of thalidomide on angiogenesis and tumor growth and metastasis of human hepatocellular carcinoma in nude mice

AIM: To investigate the effects of thalidomide on angiogenesis, tumor growth and metastasis of hepatocellular carcinoma in nude mice.METHODS: Twenty-four nude mice were randomly divided into therapy group and control group, 12 mice in each group. Thalidomide dissolved in 0.5% sodium carboxyl methyl cellulose (CMC) suspension was administered intraperitoneally once a day at the dose of 200 mg/kg in therapy group, and an equivalent volume of 0.5% CMC in control group. Mice were sacrificed on the 30th d, tumor size and weight and metastases in liver and lungs were measured. CD34 and VEGF mRNA in tumor tissue were detected by immunohistochemistry and semi-quantitative RT-PCR respectively and microvessel density (MVD) was counted. Serum concentrations of TNF-α and ALT and AFP were also tested.RESULTS: MVD and VEGF mRNA in therapy group were less than those in control group (31.08±16.23 vessels/HP vs 80.00±26.27 vessels/HP, 0.0538±0.0165 vs 0.7373±0.1297,respectively, P＜0.05). No statistical difference was observed in tumor size and weight and metastases in liver and lungs.TNF-α was significantly lower in therapy group than in control group (28.64±4.64 ng/L vs42.69±6.99 ng/L, P＜0.05). No statistical difference in ALT and AFP was observed between groups.CONCLUSION: Thalidomide can significantly inhibitangiogenesis and metastasis of hepatocellular carcinoma.Italso has inhibitory effects on circulating TNF-α.

Obesity and colorectal cancer risk: A meta-analysis of cohort studies

TO evaluate the association between obesity and colorectal cancer risk. METHODS： We searched PubMed, EMBASE, and the Cochrane Library up to January 1, 2007. Cohort studies permitting the assessment of causal association between obesity and colorectal cancer, with clear definition of obesity and well-defined outcome of colorectal cancer were eligible. Study design, sample size at baseline, mean follow-up time, co-activators and study results were extracted. Pooled standardized effect sizes were calculated.

Effects of low molecular weight heparin on platelet surface P-selectin expression and serum interleukin-8 production in rats with trinitrobenzene sulphonic acid-induced colitis

AIM:To observe the effects of low molecular weight heparin(LMWH) on platelet surface P-selectin expression and serum interleukin-8 production in rats with trinitrobenzene sulphonic acid (TNBS) induced colitis.METHODS:Colitis was induced in female Sprauge-Dawley rats by colonic administration of 2, 4, 6-TNBS. LMWH, a dalteparin (150U/kg, 300U/kg) was subcutaneously administrated one hour before induction of colitis and went on once a day for 6 days. Then a half dose was given for the next 7 days. Control animals received the same volume of normal saline once a day for 14 days after treated by TNBS.Animals were sacrificed at 24h, days 7 and 14 after induction of colitis. The colon was excised for the evaluation of macroscopic and histological findings and TNF-α immunohistochemical assay. Platelet surface P-selectin expression was determined by radioimmunoassay and serum IL-8 production was assayed by ELISA method.RESULTS:LMWH treatment in a dose of 300U/kg for 14 days significantly improved colonic inflammation by histological examination. Serum IL-8 production in the 300U/kg treatment group was more significantly decreased at day 14 than that at 24h (P<0.05). However, platelet surface P-selectin expression and TNF-α staining in colonic tissue were not significantly different among the three groups.CONCLUSION:LMWH has an anti-infiammatory effect on TNBS induced colitis in rats. The effect is possibly related to inhibition of proinflammatory cytokine IL-8, but not involved platelet surface P-selectin expression.

HLA-DRB1 allele polymorphisms in genetic susceptibility to esophageal carcinoma

AIM: To probe into the genetic susceptibility of HLA-DRB1 alleles to esophageal carcinoma in Han Chinese in Hubei Province.METHODS: HLA-DRB1 allele polymorphisms were typed by polymerase chain reaction with sequence-specific primers (PCR-SSP) in 42 unrelated patients with esophageal cancer and 136 unrelated normal control subjects and the associated HLA-DRB1 allele was measured by nucleotide sequence analysis with PCR.SAS software was used in statistics.RESULTS: Allele frequency (AF) of HLA-DRB1·0901 was significantly higher in esophageal carcinoma patients than that in the normal controls (0.2500 vs0.1397, P=0.028, the odds ratio 2.053, etiologic fraction 0.1282). After analyzed the allele nucleotide sequence of HLA-DRB1·0901 which approachs to the corresponded exon 2 sequence of the allele in genebank. There was no association between patients and controls in the rested HLA-DRB1 alleles.CONCLUSION: HLA-DRB1·0901 allele is more common in the patients with esophageal carcinoma than in the healthy controls, which is positively associated with the patients of Hubei Han Chinese. Individuals carrying HLA-DRB1·0901may be susceptible to esophageal carcinoma.

Prevention and therapy of fungal infection in severe acute pancreatitis:A prospective clinical study

AIM: To investigate the prevention and therapy of fungal infection in patients with severe acute pancreatitis (SAP).METHODS: Seventy patients with SAP admitted from Jan.1998 to Dec. 2002 were randomly divided into garlicin prevention group, fluconazole (low dosage) prevention group and control group. The incidence of fungal infection, the fungal clearance and mortality after treatment were compared.RESULTS: The incidence of fungal infection in garlicin group and fluconazole group was lower than that in control group (16 % vs30 %, P＜0.05 and 9 % vs30 %, P＜0.01,respectively). Amphotericin B or therapy-dose fluconazole had effects on patients with fungal infection in garlicin group and control group, but had no effects on patients with fungal infection in fluconzole group.CONCLUSION: Prophylactic dosage of antifungal agents (garlicin or low dosage fluconazole) can reduce the incidence of fungal infection in patients with SAR.But once fungal infection occurs, amphotericin B should be used as early as possible if fluconazole is not effective.

Effect of complex amino acid imbalance on growth of tumor in tumor-bearing rats

AIM: To investigate the effect of complex amino acid imbalance on the growth of tumor in tumor-bearing (TB) rats.METHODS: Sprague-Dawlley (SD) rats underwent jejunostomy for nutritional support. A suspension of Walker256 carcinosarcoma cells was subcutaneously inoculated.TB rats were randomly divided into groups A, B, C and D according to the formula of amino acids in enteral nutritional solutions, respectively. TB rats received jejunal feedings supplemented with balanced amino acids (group A),methionine-depleted amino acids (group B), valine-depleted amino acids (group C) and methionine- and valine-depleted complex amino acid imbalance (group D) for 10 days. Tumor volume, inhibitory rates of tumor, cell cycle and life span of TB rats were investigated.RESULTS: The G0/G1 ratio of tumor cells in group D (80.5±9.0) % was higher than that in groups A, B and C which was 67.0±5.1 %, 78.9±8.5 %, 69.2±6.2 %, respectively (P＜0.05). The ratio of S/G2M and PI in group D were lower than those in groups A, B and C. The inhibitory rate of tumor in groups B, C and D was 37.2 %, 33.3 % and 43.9 %,respectively (P＜0.05). The life span of TB rats in group D was significantly longer than that in groups B, C, and A.CONCLUSION: Methionine/valine-depleted amino acid imbalance can inhibit tumor growth. Complex amino acids of methionine and valine depleted imbalance have stronger inhibitory effects on tumor growth.

Hypermethylation of CpG island in O^6-methylguanine-DNA methyltransferase gene was associated with K-rasG to A mutation in colorectal tumor

AIM: To investigate the functions of promoter hypermethylation of O6-methylguanine-DNA methyltransferase (MGMT) gene in colorectal tumorigenesis and progression.METHODS: The promoter hypermethylation of MGMT gene was detected in 27 sporadic colorectal adenomas,62 sporadic colorectal carcinomas and 20 normal colorectal mucosa tissues by methylation-specific PCR. At the same time, the expression of MGMT protein was carried out in the same samples using immunohistochemistry. Mutantallele-specific amplification was used to detect K-rasG to A point mutation in codon 12.RESULTS: None of the normal colorectal mucosa tissues showed methylated bands. Promoter hypermethylation was detected in 40.7% (11 of 27) of adenomas and 43.5% (27 of 62) of carcinomas. MGMT proteins were expressed in nucleus and cytoplasm of normal colorectal mucosa tissues. Loss of MGMT expression was found in 22.2% (6 of 27) of adenomas and 45.2% (28 of 62) of carcinomas. The difference between them was significant (P = 0.041). In the 6 adenomas and 28 carcinomas losing MGMT expression, 5 and 24 cases presented methylation,respectively (P = 0.027, P＜0.001). Thirteen of the 19 colorectal tumors with K-rasG to A point mutation in codon 12 had methylated MGMT(P = 0.011). The frequencies of K-rasG to A point mutation were 35.3% (12 of 34) and 12.7% (7 of 55) in tumors losing MGMT expression and with normal expression, respectively.CONCLUSION: Promoter hypermethylation and loss of expression of MGMT gene were common events in colorectal tumorigenesis, and loss of expression of MGMT occurs more frequently in carcinomas than in adenomas in sporadic patients. Hypermethylation of the CpG island of MGMT gene was associated with loss of MGMT expression and K-ras G to A point mutation in colorectal tumor. The frequency of K-ras G to A point mutation was increased in tumors losing MGMT expression. It suggests that epigenetic inactivation of MGMT plays an important role in colorectal neoplasia.

Relationship between nuclear morphometry,DNA content and resectability of pancreatic cancer

AIM: To investigate the association of nuclear morphometry and DNA content with resectability of pancreatic cancer.METHODS: A total of 36 patients with pancreatic adenocarcinoma were divided into resectable group and unresectable group. The nuclear morphometry and DNA contents of tumor cells were analyzed by IBAS autoimagine analyzer from paraffin-embedded materials. Localization size,histological type and grade, and clinical stage of the tumor were evaluated. Factors influencing resectability of pancreatic cancer were investigated using stepwise regression analysis.RESULTS: Statistical significance was found in nuclear DNA content (integrated optical density, IOD) of tumor cells (1.64±0.41 vs 2.96±0.55), DNA ploidy, ages (46.5±5.3 years vs 58.6±0.7 years) and tumor volumes (298.1±101.5 cm3 vs 634.7±512.5 cm3) in both groups (P＜0.05), and no difference was found in the nuclear morphometry (P＞0.05). The rates of diploid/tetraploid and aneuploid were 66.7 % and 33.3% in resectable group respectively, and 38.9 % and 62.1%in unresectable group, respectively (P＜0.05). IOD (X12), ploidy status (X13) and clinical stage (X3) were radical resectable indicators with statistical significance. The regression equation for resectability was Y=-9.2053+3.5428X12+2.5390X13-2.3001X3(RR=0.8780, P＜0.01).CONCLUSION: There is a high correlation between resectability of pancreatic cancers and their DNA contents,DNA ploidy status and clinical stage.

Risk Factors of Cervical Carcinoma and Countermeasures against Them in Mountainous Area of Wufeng County, China

Cases (n=44) with squamous cell cervical cancer (SCCA) and age-matched healthy controls (n=176) were analyzed. Significant difference due to human papillomavirus (HPV) infection, ages at the first marriage, ages at the first sexual intercourse, ages at the first birth given to baby, number of gravidities, number of deliveries, Body Mass Index (BMI), education level of women and their husbands (p<0.05) was observed. According to multivariate logistic regression analysis, four factors have entered the model (p<0.05), including HPV infection [OR (odds ratio)=26.13, 95%CI (confidence interval)=9.40?72.60], education level of women (OR=0.41, 95%CI=0.21?0.79), education level of spouses (OR=0.45, 95%CI=0.22?0.94), BMI (OR=0.73, 95%CI=0.57?0.93). Moreover, HPV infection is relative to education level of women (r=?0.14), and their spouses (r=?0.21), age at the first marriage (r=?0.20), age at the first birth given to baby (r=?0.20) and BMI (r=?0.15).

Rapid Diagnosis with FISH for Chromosomal Abnormality of Fetal Pyelectasia

Fluorescence in situ Hybridization （FISH） was used to investigate whether the chromosome of the fetus prenatally diagnosed as pyelectasis was normal or not. Amniotic fluid was taken from the pregnant woman whose fetus was detected with pyelectasia by prenatal examination. The chromosome of the amniotic fluid cell without culture was examined with FISH. The result shows that compared with the traditional amniotic fluid cell culture, FISH has the advantages of more rapid, higher sensitivity and specificity, and was 10-12 days earlier to complete the diagnosing than the traditional method. The fetuses detected chromosomal abnormality in each groups were induced during the middle and late trimester, while those fetuses with normal chromosome continued pregnancy, the rate of spontaneous disappearance of pyelectasia decreased as the severity of pyelectasia increased. FISH can satisfy the urgent need in the clinical prenatal diagnosis due to its rapidity to determine whether fetus with pyelectasia was accompanied with chromosomal.

Development of rapid advice guideline and standard and continuous updating guideline:experiences and practice

We published rapid advice guidelines and updated guidelines for coronavirus disease 2019(COVID-19)management on February 6,2020,and September 4,2020,respectively.These two guidelines vary widely in their developmental background,type of evidence,grade of recommendation and so on.We shared our experience for the development of these two guidelines to help clinical practitioners better understand and implement guidelines and to help guideline developers facilitate communication and discussion for guideline development during the pandemic.

Activation of Proteinkinase ERK Mediates Induction of Macrophage MMP-12 by OxLDL

The present study was undertaken to investigate the effect of oxidized low density lipoprotein (oxLDL) on the expression of macrophage matrix metalloproteinase-12 (MMP-12), and the possible mechanisms. Activation of extracellular signal-regulated kinase 1/2 (ERK1/2) was detected by Western blot Analysis. Enzymatic activity of MMP-12 was determined by β-casein zymography. RT-PCR analysis was used to measure the mRNA expression level of MMP-12. OxLDL-stimulated macrophages produced increased casein-degrading activities and oxLDL also significantly increased the mRNA level of MMP-12 in a dose-dependent manner. OxLDL stimulated the phosphorylation of ERK1/2 in macrophages. The use of the specific inhibitor indicated that the ERK1/2 signaling pathway was required for the induction of MMP-12. These data demonstrated that oxLDL induced MMP-12 expression in macrophages through an ERK1/2-dependent pathway. Key words oxidized low density lipoproteins - macrophage - matrix metalloproteinases CLC number Q 556+.9 Foundation item: Supported by the Natural Science Foundation of Hubei Province (99J138)Biography: He Chun-yan (1970-), female, Ph. D candidate, research direction: biochemistry diagnosis of atherosclerosis.

Overview of the Basic Research on Vascular Surgery in China

This paper sums up the fundamental research projects on Vascular Surgery supported by National Natural Science Foundation of China from 1996 to 2000, and presents the experimental results and advances in the aspects of ischemia disease, the formation mechanism and prevention of restenosis, the development of abdominal aorta aneurysm and portal hypertention.