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 investigate the polymorphisms of 9 non-DNA combined index system (CODIS) short tandem repeats (STRs), i.e., D7S3048, D8S1132, D11S2368, D2S1772, D6S1043, D13S325, D12S391, GATA198B05, D18S1364 in Hebei Han population, and evaluate the usage of them in paternity testing.

METHODSOne hundred and forty-seven unrelated healthy individuals from the Han population of Hebei province were genotyped using STRtyper10G kit including 9 STR loci on ABI 3130 Genetic Analyzer. Hardy-Weinberg equilibrium and population genetic parameters were calculated. Fourteen cases of motherless paternity testing and 2 cases of standard trios with mutation in 1 locus were detected using STRtyper10G.

RESULTS(1) Ninety-nine alleles and 336 genotypes were observed in the 9 STR loci in the population. The cumulative discrimination power(DP) was higher than 0.999,999,999. The cumulative probability of exclusion (PE) for trios and duos were 0.999,974 and 0.998,759 respectively. Departure from Hardy-Weinberg equilibrium was not observed in any of the 9 loci. (2) The combined paternity index (PI) of the 14 cases of motherless paternity testing ranged from 10³-10⁶ for 15 STR loci in ID, whereas it reached 10⁵-10⁹ for 22 independent STR loci included in ID and STRtyper 10G. Possible mutation in FGA and vWA was observed in 2 cases of trios, and the combined PI was 5945 and 1840 respectively for 15 STR loci in ID. Adding STRtyper 10G to detect these 2 cases, the combined PI reached 2.76 × 10⁷ and 4.88 × 10⁷ respectively.

CONCLUSIONThe genetic polymorphism of the 9 non-CODIS STR loci included in STRtyper 10G was quite high in Chinese Hebei Han population, indicating the 9 STR loci are valuable as complement markers for ID and PP16 kit in motherless paternity testing, paternity testing with mutation and other kinds of complicated paternity testing.

China ; ethnology ; Gene Frequency ; Genetics, Population ; Humans ; Microsatellite Repeats ; Mutation ; Paternity ; Polymorphism, Genetic

OBJECTIVETo investigate the prognostic value of proton magnetic resonance spectroscopy (1H-MRS) in the study of warm ischemia reperfusion injury to the regeneration of hepatic cells of the livers following their orthotopic transplantation in rats.

METHODSA rat orthotopic liver transplantation (OLT) model with warm ischemia, the experimental group, was established and the same was done with a control group but without warm ischemia of the livers. They were studied at 6 time points (6 hours, 1, 3, 7, 14, and 30 days after OLT). All rats took axial T1 weighted and T2 weighted imaging scans and 1H MR spectroscopies.

RESULTSThe positive rate of proliferating cell nuclear antigen (PCNA) and the mean peak choline/water ratio in the experimental group were significantly higher than those in the control group and the peak choline /water ratio had a positive correlation with the positive rate of PCNA. Serum ALT and AST increased significantly after OLT, especially during the 6 hour to 3day period. The levels of ALT and AST were markedly higher in the experimental group compared to the control group.

CONCLUSIONWarm ischemia reperfusion injury of OLT has a significant effect on the regeneration of hepatic cells, and the choline peak of 1H-MRS can be used to evaluate the regeneration of hepatic cells non-invasively.

Animals ; Graft Survival ; Hepatocytes ; cytology ; Liver Regeneration ; Liver Transplantation ; Magnetic Resonance Spectroscopy ; Male ; Rats ; Rats, Sprague-Dawley ; Reperfusion Injury ; diagnosis ; Warm Ischemia

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