Humans ; Laparoscopy ; Proctectomy ; Rectal Neoplasms/surgery* ; Rectum/surgery* ; Transanal Endoscopic Surgery

OBJECTIVETo examine the changes of the mechanical properties of 7 different light-cured composite resins after thermal cycling and the correlations between these properties.

METHODSSeven different light-cured composite resins, including 2 microfilled composites (A110:AH and ESTELITE :ET), 3 microhybrid composites (AELITE:AT, Z250:ZS, and CharmFil plus:CP), and 2 nanohybrid composites (Z350:ZH and Grandio:GD), were prepared into test specimens with a diameter of 12 mm and a thickness of 1.0 mm. The specimens were stored in distilled water at 37 degrees celsius; for 24 h prior to 1 000 thermal cycles of 5 degrees celsius; for 15 s and 55 degrees celsius; for 15 s. The biaxial flexural strength (δ(f)) was tested using the ball-on-three-ball method at a crosshead speed of 0.5 mm/min (ISO4049). The fracture surface was observed under scanning electron microscope (SEM), and the remaining specimens underwent Knoop hardness test with a 50-g loading for 10 s.

RESULTSThe highest and lowest Weibull modulus was observed in AH (18.752) and AT (5.290) group, respectively. The highest and lowest biaxial flexural strength was observed in ZS (158.2 MPa) and ET (54.0 MPa) groups, respectively. The δ(f) of the tested materials decreased in the order of microhybrid composite, nanohybrid composite, and microfiller composite, and the δ(f) showed no significant difference between the composites with a similar filler (P>0.05). The fracture number was positively correlated to the strength of the material. The Knoop hardness numbers (H) was the highest in GD group (110.81∓14.77 kg/mm(2)) and the lowest in AH group (42.81∓1.91 kg/mm(2)). SEM showed that the interface region of the matrix and the filler was vulnerable to crack formation.

CONCLUSIONThe nanohybrid composite resins better suit clinical applications than microhybrid composites. The applicability of Knoop hardness test in hardness measurement of the composite resins needs to be further demonstrated.

Composite Resins ; chemistry ; Materials Testing ; Nanocomposites ; Nanoparticles ; Stress, Mechanical ; Temperature ; Tensile Strength

OBJECTIVETo investigate the clinicopathological characteristics of advanced colorectal cancer which was 30 mm or smaller in diameter.

METHODSRetrospective analysis documented 80 patients with small advanced colorectal cancer from May 1985 to May 2002. According to the diameter of tumors, all patients were divided into three groups: Group A (10 mm or less), Group B (11-20 mm), Group C (21-30 mm). Considering the number of patients in Group A was smaller, we combined Group A with Group B as Group D. Then various clinicopathological characteristics were compared between Group C and Group D.

RESULTSThe most common site of small advanced colorectal cancer was sigmoid colon and rectum that accounted for 36.2% and 35.0% of all cases. The average diameter of total tumors was 23.3 mm. Type 2 was the most common macroscopic type (63.7%) and the moderate differentiation was seen in 77.5% of cases. Thirty-eight (47.5%) cases had lymph node metastasis. Three (3.8%) cases had liver metastasis and three (3.8%) cases had peritoneal metastasis. The frequency of lymph node metastasis was found significantly different between Group C and Group D (54.2% vs. 28.6%, P < 0.05) , as well as between the groups with different depth of invasion (P < 0.05). Curability A resection was performed in 69 (86.2%) cases.

CONCLUSIONSTumor size and depth of invasion are related to lymph node metastasis in small advanced colorectal cancer. However, the small size of tumor may not always be a reliable parameter for estimating the risk of lymph node metastasis. Small colorectal cancers also do not always mean the early stage. Surgeons should be aware of the features of small advanced colorectal cancers to select ideal management and perform perfect resection.

Aged ; Aged, 80 and over ; Carcinoembryonic Antigen ; blood ; Colorectal Neoplasms ; pathology ; surgery ; Female ; Humans ; Japan ; Laparotomy ; Lymphatic Metastasis ; Male ; Middle Aged ; Neoplasm Staging ; Retrospective Studies

OBJECTIVETo investigate the expression of reversion-inducing cysteine-rich protein with Kazal motifs (RECK), matrix metalloproteinase-9 (MMP-9), and vascular endothelial growth factor-C (VEGF-C) in colorectal cancer.

METHODSS-P immunohistochemistry was used to detect the expression of RECK, MMP-9 and VEGF-C in colorectal cancer specimen. Colorectal mucosal tissue at least 10 cm away from the tumor was used as control.

RESULTSThe positive expression of RECK in colorectal cancer was significantly lower than that in the controls(53.3% vs. 100%, P<0.05). Both MMP-9 and VEGF-C were over expressed compared with the controls(86.7% vs. 23.3% and 71.7% vs. 13.3% respectively, P<0.01). The expression of RECK was negatively correlated with that of MMP-9 and VEGF-C, and the expression of MMP-9 was positively correlated with that of VEGF-C. There were significant associations between the expression of these proteins and lymph node metastasis, distant metastasis, and TNM staging (all P<0.05).

CONCLUSIONSRECK expression is low in colorectal cancer, while MMP-9 and VEGF-C expressions are high. Combined testing of these 3 markers is important in the evaluation of tumor metastasis and invasion, and is helpful in the prediction of the prognosis.

Adult ; Aged ; Colorectal Neoplasms ; genetics ; metabolism ; pathology ; Female ; GPI-Linked Proteins ; metabolism ; Humans ; Male ; Matrix Metalloproteinase 9 ; metabolism ; Middle Aged ; Prognosis ; Vascular Endothelial Growth Factor C ; metabolism

OBJECTIVETo establish a novel Myc gene transgenic mouse model for spontaneously forming B-lymphoma and assessing its tumorigenesis potential.

METHODSFreshly isolated hematopoietic progenitor cells served as the target for Myc gene transfer mediated by a retrovirus vector. These cells were engrafted into C57BL/6 mice with (60)Co-gamma ray radiation in advance. Tumor latency was measured and the tumor loaded mice were followed for survival time. Tumor was identified with histology and immunostaining. The exogenous Myc gene was detected by Western blot (in liver, spleen, tumor tissue) and flow cytometry (FCM) \[in bone marrow (BM)\].

RESULTSMice BM-infected with mutant Myc gene more readily gave rise to B-cell lymphomas than those infected with wild type Myc gene did Myc gene was expressed highly in BM and tumor tissues but not in liver and spleen.

CONCLUSIONOur model will be a tool in assessing the transforming potential of Myc mutants and in studying cooperation between Myc and other oncogenes. Mutant Myc is more effective than wild-type Myc in promoting B cell lymphomagenesis in mice.

Animals ; B-Lymphocytes ; Cell Transformation, Neoplastic ; Flow Cytometry ; Lymphoma ; Lymphoma, B-Cell ; Mice ; Mice, Inbred C57BL ; Mice, Transgenic ; Retroviridae Infections

Aim To explore the role of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase in high fat-induced oxidative stress injury in human umbilical vein endothelial cells (HUVECs).Methods HUVECs were exposed to different concentrations of palmitic acid(0.1,0.2,0.4,0.8 mmol · L-1) for 24 h and different time points of 0.4 mmol · L-1 palmitic acid(0,12,24,48 h).Cell viability was measured by Cell Counting Kit 8,and the protein expression of NADPH oxidase subunits such as p22phox,p47phox,p67phox and gp91phox were determined by Western blot.The expression of reactive oxygen species (ROS) in HUVECs was detected by immunofluorescence.Results Cell proliferation rate of HUVECs stimulated by 0.4 mmol · L-1 palmitic acid for 24 h and 48 h was significantly reduced.In the next experiment,model group was accordingly set as HUVECs stimulated by 0.4 mmol · L-1 palmitic acid for 24 h.The expression of NADPH oxidase subunits such as p22phox,p47phox,p67phox and gp91phox significantly increased at 24 h and 48 h after 0.4 mmol· L-1 palmitic acid stimulation (P ＜ 0.05),and the difference.between the 24 h group and the 48 h group was not significant (P ＞ 0.05).The expression of ROS in HUVECs significantly increased at 24 h and 48 h after O.4 mmol · L-1 palmitic acid stimulation (P ＜ 0.05),and the difference between 24 h group and 48 h group was not significant (P ＜ 0.05).Compared with the model group (0.4 mmol · L-1 palmitic acid stimulation for 24 h),the NADPH oxidase inhibitor diphenyliodonium (DPI,10 μmol · L-1) pretreatment could significantly decrease the expression of ROS in vascular endothelial cells (P ＜ 0.05).Conclusion Activated NADPH oxidase might play an important role in treatment of high fat-induced oxidative stress injury in vascular endothelial cells.

OBJECTIVETo explore the risk factors for hepatoblastoma.

METHODSA case-cohort study using Logistic regression multiple variables analysis of medical record data sets was conducted to examine infant and perinatal risk factors for hepatoblastoma.

RESULTSBirth weight less than 1,000 g was associated with a strongly increased risk of hepatoblastoma (odds risk, OR = 26.0, 95% confidence interval, CI: 14.0 to 65.7). After adjustment of birth weight, a moderately increased risk of hepatoblastoma was found for older maternal age ( > 35 years vs. 20 to 34 years: OR = 2.6, 95% CI: 0.9 to 5.9), maternal smoking (OR = 2.9, 95% CI: 1.1 to 4.2) and higher maternal pregnancy body mass index (OR = 3.2, 95% CI: 1.0 to 6.7).

CONCLUSIONVery low birth weight and maternal characteristics including overweight, smoking are associated with hepatoblastoma risk.

Case-Control Studies ; Child ; Child, Preschool ; Confidence Intervals ; Female ; Follow-Up Studies ; Hepatoblastoma ; epidemiology ; etiology ; prevention & control ; Humans ; Infant ; Infant, Newborn ; Infant, Very Low Birth Weight ; Liver Neoplasms ; epidemiology ; etiology ; prevention & control ; Male ; Overweight ; Pregnancy ; Retrospective Studies ; Risk Factors ; Smoking ; adverse effects

OBJECTIVETo summarize the diagnostic and therapeutic experiences of acute mesenteric venous thrombosis (MVT).

METHODSThe clinical data of 27 cases of acute MVT treated between 1983 and July 2007 were analyzed retrospectively.

RESULTSThe courses of disease were from 1 to 14 days (mean, 6.1 days). Eighteen cases (66.7%) had the history of portal hypertension, deep vein thrombosis, acute MVT or other hypercoagulability. The diagnostic sensitivity of ultrasonography, CT, angiography and serum D-Dimer level were 70.6% (12/17), 75.0% (6/8), 100% (6/6), 100% (6/6), respectively. Bowel necrosis occurred in all the 16 cases with bloody ascites. The thrombolytic and anticoagulation therapy are effective in 36.4% of cases (4/11). Twenty-two cases received operation, and resection of necrotic bowel was performed in all and thrombectomy in 3 cases. The main postoperative complications included 3 cases of deep vein thrombosis, 1 acute cardiac infarction, 3 short bowel syndrome. MVT recurred in 4 cases within a week after operation. Eight patients died within a month after confirmed with acute MVT, in which 7 patients died after operation. Anticoagulation medication was implemented in all the 19 survived patients. Fifteen patients were followed-up for 1-120 months (mean, 39.2 months), 7 of them continued the anticoagulation therapy during this period.

CONCLUSIONSThe determination of serum D-Dimer level and such adjuvant examinations as ultrasonography, CT and angiography are important diagnostic means for acute MVT. Anticoagulation and thrombolysis should be considered firstly if there is no active bleeding and bowel necrosis. We recommend laparotomy when bowel necrosis is suspected.

Adult ; Aged ; Female ; Follow-Up Studies ; Humans ; Male ; Mesenteric Veins ; Middle Aged ; Retrospective Studies ; Venous Thrombosis ; diagnosis ; therapy

OBJECTIVETo investigate the polymorphism of loci DXS6800, DXS6797, GATA172D05, DXS986 four loci in Hebei Han population.

METHODSThe genome DNA of unrelated individuals,the families and rotten materials were extracted with phenol-chloroform method and Chelex-100 method,respectively. The PCR products were detected by the polyacrylamide gel electrophoresis and DNA sequencing analysis.

RESULTSAmong 150 unrelated males and 150 unrelated females from Hebei Han population, 25 alleles were found in the 4 loci. One hundred and thirty-eight haplotypes of the male were detected. The haplotype diversity reached 0.9986.

CONCLUSIONThe findings provided the polymorphic data of DXS6800, DXS6797, GATA172D05, and DXS986 loci in Hebei Han population. The four loci are relatively abundant in polymorphic information for identification and the obtained data of Hebei Han population can be applied to the X-STR genetic data bank.

Alleles ; Chromosomes, Human, X ; Female ; Genetics, Population ; Humans ; Male ; Polymorphism, Genetic ; Tandem Repeat Sequences ; genetics

OBJECTIVETo investigate the effects of promoter methylation of p16, death-associated protein kinase (DAPK) and retinoic acid receptor-beta (RAR beta) genes on clinical data in non-small cell lung cancers, and to study the effect of smoking on the risk of gene methylation.

METHODSThe promoter methylation of p16, DAPK and RAR beta genes in 200 primary non-small cell lung cancers and the corresponding nonmalignant lung tissues were determined by methylation-specific PCR.

RESULTSMethylation in the tumor tissues was detected in 51.0% for p16, 60.0% for DAPK, and 58.0% for RAR beta gene, with significant differences (P < 0.05) when compared with those in the corresponding nonmalignant tissues(12.5%, 11.5% and 15.0%) respectively. p16 gene methylation in tumor tissue was associated with age significantly in unconditional logistic regression analysis (P < 0.01) and histologic type (P < 0.05). DAPK gene methylation in tumor tissue was associated significantly with age (P < 0.05), gender (P < 0.05) and clinical type (P < 0.05). RAR beta gene methylation in tumor tissue was associated with clinical type (P < 0.05) and tumor stage (P < 0.05) significantly. The interaction odds ratio (OR) for the gene-gene interaction in tumor tissue between p16 and DAPK was 1.987 (95%CI:1.055-3.743). The results of the gene-smoking analyses revealed that a relationship existed between cigarette smoking and p16 gene methylation (OR = 3.139, 95%CI: 1.046-9.419), the OR for the relationship of DAPK gene methylation and cigarette smoking was 3.585(95%CI: 1.270-10.123) in tumor tissue. The RAR beta gene methylation did not differ based on the smoking status of patients in tumor tissue.

CONCLUSIONThe p16, DAPK and RAR beta genes methylation are strongly associated with clinical data of non-small cell lung cancer, and methylation of p16 and DAPK genes are associated with tobacco smoking.

Apoptosis Regulatory Proteins ; genetics ; Calcium-Calmodulin-Dependent Protein Kinases ; genetics ; Carcinoma, Non-Small-Cell Lung ; etiology ; genetics ; pathology ; DNA Methylation ; Death-Associated Protein Kinases ; Genes, p16 ; Logistic Models ; Lung Neoplasms ; etiology ; genetics ; pathology ; Neoplasm Staging ; Promoter Regions, Genetic ; Receptors, Retinoic Acid ; genetics ; Smoking ; adverse effects